Compost Use In Florida
Produced by the Florida Center for Solid and Hazardous Waste Management for the Florida Department of Environmental Protection, December, 1998
Printed on recycled paper ~~~ Contributors...... 5 Figures and Tables...... 6
Introduction Beyond the Backyard Compost Pile...... 7
Part I: The Basics Chapter 1:Compost and Waste Management in Florida...... ~ . . . .9 Mitch Kessler and Allison Searccy Chapter 2: What Is Compost?...... 12 Margie Lynn Stratton and Jack E. Rechcigl Chapter 3:Developing a Market for Compost Products...... 15 Aziz Shiralipour
Part II: Regulatory and Quality Assurance Issues Chapter 4:Regulations Affecting Compost Production and Use . . . .18 Francine Joyal Chapter 5:Compost and Quality Assurance...... 21 George E. Fitzpatrick Chapter 6:How to Produce High Quality Compost ...... 24 Patrick D. Byers
Part Ill: Agricultural Uses for Compost in Florida Chapter 7:The Effects of Compost on Soil...... 27 Aziz Shiralipour Chapter 8:The Benefits of MSW Composts in South Florida ...... 30 Dean Richardson Chapter 9:How Compost Benefits Citrus Crops...... 32 J.H. Graham Chapter 10:Growing Field Crops with Compost...... 36 R.N. Gallaher Chapter 11:Use of Composts on Florida’s Vegetable Crops ...... 39 Monica P. Ozores-Hampton and Thomas A. Obreza Chapter 12:Compost Uses for the Landscape and Nursery Industries...... 43 George E. Fitzpatrick and Dennis B. McConnell Chapter 13:Use of Compost on Turfgrasses...... 45 John L. Cisar and George H. Snyder Chapter 14:Compost Use on Forest Lands...... 48 H. Reikerk Chapter 15:Reclamation of Phosphate Mine Lands with Compost...... 51 James Ragsdale Glossary...... 55 References...... 57
COMPOST USE IN FLORIDA 3 . . Patrick Byers i Thomas A. Obreza .! Searcy (not pictured) Solid Waste Authority : University of Florida, i TIA Solid Waste Management . of Palm Beach . Institute of Food and .: Consultants, Inc., Tampa, Fla. County, West Palm ! Agricultural Sciences, i . Beach, Fla. . Southwest Florida i. . . Aziz Shiralipour . Research and . University of Florida, i Education Center, Immokalee, Fla. i Center for Biomass John L. Cisar University of Florida, Monica P. Ozores- . Gainesville, Fla. Fort Lauderdale Hampton . Research and University of Florida, i Education Center, Institute of Food and : George H. Snyder (not pictured) Fort Lauderdale, Fla. Agricultural Sciences, ! Southwest Florida i University of Florida, Everglades Research and Education George E. Research and Education Center, . . Center, Belle Glade, Fla. Fitzpatrick . Immokalee, Fla. University of Florida, i. . . Margie Lynn Stratton (not pictured) Fort Lauderdale : Andrew S. Pike (not pictured) University of Florida, Institute of Research and . Sun-Ray and Southern Farms, Food and Agricultural Sciences, Education Center, [ Lake Placid, Fla. Range Cattle Research and Education Fort Lauderdale, Fla. : . Center, Ona, Fla. . James Ragsdale ; R.N. Gallaher ; Sanitation Produced by the Florida Center ~ Department of i Department, . for Solid and Hazardous Waste Agronomy, . City of St.Petersburg, i Management, University of University of Florida, : St. Petersburg, Fla. i Florida, College of Engineering, Gainesville, Fla. : . Gainesville, Fla. . . . Jack E. Rechcigl / Executive Director, John Schert J.H. Graham . University of Florida, ! University of Florida, i Institute of Food and i Technical Editor, Diana Tonnessen Citrus Research and .i Agricultural Sciences, i . Education Center, : Range Cattle . Graphic Design, Production Ink Lake Alfred, Fla. .i Research and . . . . Joyal i H. Reikerk . Florida Department i. School of Forest i. of Environmental i. Resources and i . Protection, . Conservation, Tallahassee, Fla. i. University of Florida, i . Gainesville, Fla. .i Mitch Kessler (not pictured) . TIA Solid Waste Management Dean Richardson i. Consultants, Inc., Tampa, Fla. Reuter Recycling of i . Florida, Pembroke / / Dennis B. McConnell i Pines, Fla. and . Tropical Treescapes, i University of Florida, .i \ . Miami, Fla. . Environmental . . Horticulture . Department, Gainesville, Fla. i.
COMPOST USE IN FLORIDA 5 ACKNOWLEDGMENT
The Center for Biomass Programs, of the University of Florida's Institute of Food and Agricultural Sciences coordinated the development of the guide by identifying contributors, editing the papers, obtaining illustrative photographs and served as the general liaison with the authors in developing their papers. Specifically, we would like to note the day-to-day efforts of Dr. Aziz Shiralipour and Ms. Sharon Thurlow, staff of the Center for Biomass Programs.
COMPOST USE IN FLORIDA 6a .
Figure l-l: Composition of Florida’s Waste Stream...... 10 13 ; Figure 2- 1: Food Web of the Compost Pile...... Figure 5- 1: Compost Used as a Growing Medium with Container Plants...... 22 . . Figure 9- 1: Increased Growth of Compost-Treated Tangelo . . Trees ...... 35 . Figure 9-2: Applying Compost to Citrus Trees...... 35 Figure 1 l-l: Watermelon Grown in Sandy Soil With and . 41 ; Without Compost Application...... Figure 1 l-2: Compost Application Eliminates Ashy Stem Blight : in Bush Beans...... 41 ; Figure 12- 1: Compost Used as a Growing Medium for Container-Grown Dwarf Oleanders...... 44 . Figure 12-2: Compost Used as a Growing Medium for Container-Grown West Indian Mahogany ...... 44 Figure 14-1: Compost Applied as a Topdressing Between Tree i Rows in a Slash Pine Forest...... 49 ;
Table 3-l: Steps for Successful Compost Market . Development...... 16 ! . 19 ! Table 4- 1: Quality Limits for Compost...... Table 4-2: Classification of Compost Made from . Solid Waste...... 19 ; . Table 10- 1: Compost Use and Corn Silage Yield ...... 38 . Table 1 l-l: Physical Properties of Compost used in . Vegetable Production...... 40 Table 13-1: Effects of Compost on Nutrients in Turfgrass ...... 46 Table 13-2: Relationship Between Turfgrass Topdressing Rates and Depth...... 46 ;
6COMPOST USE IN FLORIDA PART I: THE BASICS/INTRODUCTION
Beyond the Backyard William Hinkley, ct Compost Pile THE BUREAU OF SOLID AND HAZARDOUS WASTE FLORIDADEPARTMENTOF ENVIRONMENTALPROTECTION The use of compost is proving to be an environmentally- TALLAHASSEE$?LORIDA friendly, potentially profitable business forcl Florida 3 JOHND.SCHERT,EXEC~TI~DIRECTOR agricultural interests. FLORIDACENTERFORSOLIDAND HAZARDOUSWASTEMANAGEMENT UNIVERMTYOF~ORIDA GAINESVILLE,FLORIDA
n 1992, to address the problem . tons of urban plant debris . of decreasing space in Florida’s . annually. And solid waste . I landfills, the State of Florida . managers are targeting other prohibited the disposal of grass i organic materials as potential . . clippings and other yard refuse in : candidates for cornposting, . lined landfills. However, the ban .i including food, liquid, and animal i . also gave rise to a promising .: residues. . industry based on a natural . This guide presents an WILLIAM HINKLEY JOHND. SCHERT process as old as life itself: .i overview of some of the benefi- cornposting. Compost, a mixture i cial uses of composts in Florida consisting largely of decayed i and discusses the factors that . organic material, occurs naturally ! influence the production, quality, . every time trees shed their . and use of compost. Included are autumn leaves. As the dead leaves : the results of 10 scientific studies decompose, they protect and .! by researchers at the Institute of enrich the soil underneath. Now i Food and Agricultural Sciences this simple, natural process is i (IFAS), demonstrating how being transformed into a sophisti- : compost can have a positive cated science, one that extends far i impact on agricultural operations beyond the backyard compost ; in Florida. The information is heap and that offers numerous i intended to help agricultural benefits for Florida’s agricultural .! interests, regulatory agencies and interests and the environment. [ the general public better under- Given Florida’s year-round !. stand cornposting and the use of growing season and porous, : compost products, and its great . sandy soils, the humus-like . potential in improving Florida’s substance which results from . soils and environment. 0 cornposting has numerous practical applications in the state. . . These include field crops and . . vegetables, landscaping and horticulture, citrus groves, golf [ . courses, forest lands, and . phosphate mine reclamation. i Florida now has 12 permitted .i cornposting facilities and dozens i of mulching facilities, which help i to recycle more than 1.3 million i
COMPOST USE IN FLORIDA 7 PART I: THE BASICS/CHAPTER 1
Compost and Waste Management in Florida Florida’s growing population, year-round growing season, and large agricultural industry provide a unique environment for the development of organic recycling/ composting programs. MIT~HKESSLERANDALLI~~N S~mcy TIASOLID Wfwm MANAGEMENTCONSULTANTSIN~. TAMPA,FLORIDA
lorida is the fourth most serve as disposalfacilities for non- next decade. They continue to populous state and one of recovered materi.als. expand their programs to target F the fastest-growing in the In an effort to maximize the new materials and to explore United States. Its mild climate recovery of valuable materials i other sources for the recovery of and year-round sunshine attract from the waste stream, in 1988, : additional materials. To maximize hundreds of new residents to the the Florida legislature enacted the [ recovery rates, solid waste profes- state every day and over 40 Solid Waste Management Act .i sionals have turned their attention million tourists each year. For that mandated a 30 percent to materials which have been Florida’s solid waste managers, recycling goal for Florida . relatively neglected. These include this booming population, plus the counties. The impact of this ; paper, comprising 26.3 percent of load from tourists, translates into legislative initiative has been i. all municipal solid waste (Figure a growing waste stream. In 1995, impressive. In response, counties i l-l), and construction and Florida’s population was more have implemented curbside and i demolition debris, comprising than 14 million, and the total drop-off recycling programs, .i 22.6 percent of the waste stream. municipal solid waste (MSW) encouraged recycling participa- i With Florida’s warm climate generated that same year was tion within the commercial sector, i and lush subtropical landscapes, close to 23 million tons - a and developed a variety of urban i urban plant debris (UPD) presents waste generation rate of approxi- plant debris mulching and the most interesting potential for mately 9 pounds per person per cornposting programs. Today, increased recycling in the state. day. These figures are approxi- Florida has more than 300 As Figure l-l indicates, UPD mately twice the national average curbside recycling programs, 12 i represent 14.4 percent of of about 4.3 pounds per person permitted cornposting facilities, i Florida’s MSW stream. In 1992, per day. and numerous other mulching i to encourage recycling of this facilities. According to Florida i valuable organic material, the Keeping Pace With a Department of Environmental i Florida Legislature passed a law Growing Population Protection (FDEP) statistics, : prohibiting the disposal of UPD To manage this burgeoning more than half of Florida’s 52 i in landfills designed to accept waste stream, Florida relies on a counties have achieved recycling / municipal solid waste. In variety of methods, including rates of 25 percent or higher. : response, the majority of . waste reduction and recycling, . Florida’s counties have imple- landfilling, and combustion. Expanding the Focus i mented source-separated UPD Waste reduction programs are From 1989 to present, the / collection systems. Researchers designed to limit the production amount and percentage of . estimated that by 1995 more than of waste, reducing the need to materials recycled in Florida has ! 3.3 million tons of UPD were manage it. Recycling programs increased steadily. Despite the : generated in Florida every year. recover valuable materials from success of existing recycling i Yet studies indicated that only the waste stream so that the programs, Florida’s solid waste i approximately 53 percent of these materials can be reused. Landfills managers have their eyes on the .: organics were recycled.
COMPOST USE IN FLORIDA 9 CHAPTER I: COMPOST AND WASTE MANAGEMENT IN FLORIDA
Office Paper 0th:; itPer composting projects. . 0 Food Waste . Corrugated Paper I 5.4% Other recent projects have moved beyond traditional urban . plant debris processing and composting to target other . organic materials, including food, liquid, and animal residuals. Florida’s organic recycling . . programs continue to expand . with the support of innovations in collection methods (especially . co-collection of organics in split collection vehicles), and increased White Goods . C & dDebris . on-site processing. 0.9% Tires A An, 22.6% For organics recycling to . .. occur, compost safety standards must be defined, and safe, eco- nomically sound uses for compost . must be identified through coordi- nated research programs. Such a Figure l-l: Composition of Florida’s Waste Stream (Jan. 1, 1995-Dec. 31, 1995) market development research . effort is under way through a Undeniably, there was room for example, the Florida Department ! partnership involving the Florida improvement. . Department of Environmental . of Transportation has adopted i That improvement began in . specifications for composted i Protection, the Florida Center for . 1995, when the FDEP approved materials and mulches made from : Solid and Hazardous Waste the deregulation of UPD com- . urban plant debris, and has . Management, and the University posting, a move that cleared the . demonstrated the cost effective- i of Florida’s Institute of Food and way for industry expansion. At . ness and superior performance of i Agricultural Sciences. the same time, cornposters have organic compost materials in its : Perhaps the most important . begun focusing their efforts on . Right-of-Way landscaping and : factor influencing developments . establishing consistent product maintenance programs. In this i in Florida’s solid waste manage- definitions, quality control . supportive environment, Florida : ment practices is the increasing standards, and uniform testing. can expect to experience contin- : pressure to improve the efficiency If Florida’s emerging compost ued growth in urban plant debris i and accountability of municipal industry is to flourish economi- processing and cornposting. i solid waste management . cally, buyers of composted . programs. Variable rate collection organic material need to know . Anticipating Future Trends i programs are expected to grow, exactly what they are buying and Florida’s growing resident i driven by the push for greater . be assured that each product’s . and non-resident population, ! reduction in sources, and an quality is consistent. . year-round growing season, and ! increase in return on investment. At the same time, researchers . large agricultural industry / In Florida’s present economic, have focused their attention on . combine to provide a unique i legislative and regulatory environ- evaluating the composting process environment for the development ! ment, the future for recycling and exploring opportunities for of other organic recycling/ i organics looks particularly bright. expanding its use. The commer- i composting programs. In addition i In sum, Florida’s composting cial marketing of compost to UPD, other organic materials ! industry is like a sleeping giant products has been encouraging. i are gaining notice as potentially i about to awaken to a coming Compost has found one niche in ’ recoverable portions of the waste i decade of healthy growth and agricultural applications in the ; stream. This renewed interest in i energetic activity, when recycling cattle and citrus industries. organics has spawned a variety of i of organics will play an increas- Additionally, favorable govern- ! innovative research and develop- : ingly important role in managing ment purchasing policies have ment projects, including MSW i Florida’s MSW stream. 0 helped to expand markets. For composting and vermi-
l()COMPOST USE IN FLORIDA CHAPTER I: COMPOST AND WASTE MANAGEMENT IN FLORIDA
COMPOST USE IN FLORIDA 11 PART I: THE BASICS/CHAPTER 2
What isCompost? Once consideredwaste products, composted urban plant debris and otherorganic materials have the potential to breathe new life into Florida’s sandy, nutrient-poor soils.
MAJXGIE LYNN STRATTON AND JACK E. RECHCIGL
UNIWWTY OF FLORIDA/INSTITUTE OF FOOD AND
AGRICULTURAL SCIENCES
RANGE CATTLE RESEARCH AND EDUCATION CENTER
ONA, FLORIDA
omposting is a biological . breaking down complex carbohy- i millions of years. In natural . process in which microor- . drates into simpler forms, which / settings, such as under forest C ganisms convert organic bacteria can use for food. The ! canopies, cornposting occurs as matter into a stabilized, humus- nutrients that become available leaf litter decomposes into like substance. Many of the . during decomposition remain in ! humus. With the advent of crop organic materials used for com- . . the compost within the bodies of i cultivation and animal husbandry, posting are inappropriate in their . new microorganisms and as . the resulting plant residues and raw form for use on land or . humus. Not all decomposition is ! animal manures were sometimes around living organisms because . microbial; in fact, it starts with : decomposed by gathering them of the presence of odors, weed macroorganisms, including earth- / into mounds or piles to allow seeds, human pathogens, and . worms, grubs, millipedes, spring i cornposting to occur. storage and handling constraints. . tails, and centipedes, which assist i Farmers, greenhouse . . Cornposting helps to break down . in the process by digging, operators, nursery crop managers, .. organic residues, stabilize . chewing, and mixing compostable i landscapers, orchardists, backyard . . nutrients, destroy weed seeds, and materials. . and organic gardeners have been control possible toxins or diseases . The cornposting process does i making small compost heaps . (Barker, 1997; Stratton et al., . not stop at a specific point but i informally for decades, often 1995; Hoitink and Keener, 1993; continues until the remaining i simply to save the cost of Haug, 1993). The resulting com- nutrients are consumed by the last i transporting and disposing the post has numerous horticultural . remaining organisms and until i materials. During the past few and agronomic benefits and is . most of the carbon is converted i decades, cornposting has become environmentally safe for use on into carbon dioxide and water a sophisticated and somewhat . soils around plants, humans, and (Rynk, 1992). well-researched science. And animals (Stratton et al., 1995; Compost has many beneficial i while cornposting is still practiced Barker, 1997). . uses. Compost improves soil ! on a backyard or small-farm scale, . Controlled decomposition aeration, soil drainage, the water- i more and more often, it is now . occurs as the result of the activi- . holding capacity of sandy soils, ./ carried out on a large scale as part . . ties of naturally occurring macro- . the percentage of organic . of local municipal waste manage- . and microorganisms (Figure 2- 1). . materials in soils, and the ability i ment programs. On a municipal Bacteria, actinomyces, and fungi . of soils to absorb and hold level, cornposting operations are the primary microorganisms nutrients. usually require sophisticated involved in decomposition. To machinery and engineering . grow and multiply, these micro- Cornposting Past and (Stratton et al., 1995; Hoitink and . organisms require carbon as an Present Keener, 1993; Haug, 1993). . energy source, nitrogen to build . The simplest form of corn- 1 The first recorded method of proteins, moisture, and oxygen. posting -the decomposition of : cornposting community wastes Enzymes, the active proteins, are , plant materials where they fall - i was developed in India by Sir produced by bacteria and assist in has been occurring naturally for i Albert Howard in 1925. This
IZCOMPOST USE IN FLORIDA CHAPTER 2: WHAT IS COMPOST? . . method, called the Bangalore or ! Ken McEntree personal commu- ; composted and applied to many Indore system, simply involved i nication). During the 14 years .i crops, including forage pastures, alternate layering of wastes in : prior to 1997, biosolids com- ; with improved yields and other trenches. Over time, as the scope i posting facilities have increased i benefits (Shiralipour et al., 1992a; . and scale of cornposting from 90 total projects nationwide i Stratton and Rechcigl, 1997). increased with the amounts and i (61 operating facilities) to 332 .i Coal bottom and fly ash, cement types of waste products handled, total projects (262 operating .i kiln dust, biosolids, water treat- innovative methods were devised facilities) as reported by Goldstein i ment sludges, food processing to speed or ease the process. The and Block (1997’0). Seven states i by-products, animal and plant layers were mounded, spread, reported a decrease in biosolids i residues, by-products from metal aerated with forced air, turned, cornposting from 1996 to 1997 i smelting, paper and wood indus- enclosed, exposed, chopped, (Goldstein and Block, 1997b). i tries by-products, tannery sludges, ground, dried, wet, sifted, i textiles production by-products, dumped from platforms, conveyed i i rock dusts, chemical and drug . Compost Materials up belts, or separated at the . Any number of materials, or i production by-products have all source, for example. For the most i feedstocks, can be composted, i been composted and land-applied part, the various processes were : including grass clippings and i (Stratton and Rechcigl, 1998). named for the company or . other types of urban plant debris, Unfortunately, not everything inventor involved with the latest i biosolids (commonly known as i that can be composted is com- innovation and are summarized i sewage sludge), and other i posted. Barker (1997) estimates organic materials. Recently, there i that 827 million tons of com- in a review article by Stratton et .i al. (1995). . has been an increased interest in : postable materials are produced In the United States during a i cornposting municipal, industrial, .i each year, largely by agriculture, recent 5 year period, cornposting i and agricultural by-products : municipalities, and industry. facilities have increased from ! (Stratton and Rechcigl, 1998). i However, only 140 million tons, . 2,200 to almost 3,500 Municipal solid waste, commonly .i or 17 percent, of those are (Christopher and Asher, 1994; i called trash or garbage, has been i collected for cornposting.
Figure 2-1: Food Web of the Compost Pile
umers
Source: Dr. Daniel Dindal, cited in Michigan Department of Natural Resources (1989). Yard Waste Composting Guide
COMPOST USE IN FLORIDA 13 CHAPTER 2: WHAT IS COMPOST?
. . Cornposting Methods : biosolids. With proper mixing . refers to properties of the . Currently, some of the best .i and ratios, and attention to compost that include, but are not . . processes for cornposting . aeration, particle size, moisture . limited to municipal solid waste or biosolids i content and other engineering . n lack of plant toxins, such include separating the source : considerations, the resulting as acetic acid, phenols, and materials at their point of origin : carbon-to-nitrogen ratio helps to ammonia speed and enhance the compost- n stabilization (temporary (source separation), reducing the .[ size of the materials (size ing process while also producing immobilization) of nutrients such reduction), and carefully mixing, a high quality end product as nitrate-N, phosphorus, iron or aerating, and curing the compost (Stratton et al., 1995; Haug, 1993; other elements which could for a few to several months to Barker, 1997). In Florida, the otherwise enrich ground or ensure compost maturity and i Palm Beach County Solid Waste surface waters stability. Authority’s cornposter is such a n the absence of detrimental The composition and method i facility. bacteria, fungi and noxious odors of processing compost varies : For each combination of n the presence of desirable greatly with the feedstock i materials, compost mixes and microorganisms, and composted (Stratton et al., 1995; [ ratios of feedstocks, as well as n a noticeable reduction of Barker, 1997). If two or more i methodology and processes, are heating upon rewetting (Stratton materials are composted together, specifically engineered for the et al., 1995). a method known as co-composting, materials being composted and Several quick bioassays have the cornposting process may be i may be site-specific (Haug, 1993). been developed to check compost Much research is currently maturity. An easy method is a accelerated and the composition .i of the final product may be . directed at cornposting of seed germination test on compost greatly enhanced as a soil amend- .i previously disposed resources and extract. (A. Shiralipour, ment and conditioner (Stratton i by-products of several industries University of Florida, personal and Rechcigl, 1997). For example, i (Stratton and Rechcigl, 1998). communication). Others prefer two materials composted together i Compost maturity has been carbon dioxide release (Graetz, may include one high in carbon, : determined in a number of ways 1996) or oxygen uptake such as woody plant materials, i by a number of different measurements. 0 and one high in nitrogen, such as i researchers. In general, maturity
14COMPOST USE IN FLORIDA PART I: THE BASICS/CHAPTER 3
Developing a Market for Compost Products The potential market for compost products in Florida is great. The challenge is convincing the consumer to use compost. AZIZ sHIRALIPouR CENTERFOR BIOMASS PROGRAMS UNIVERsITYOF~ORIDA GAINESVILLE,~?LORIDA
he growth of the compost statewide, as many as 42 million i requirements of end uses, which industry in the United States tons of compost could be used i may vary widely. Many commu- T and Florida is being driven annually within a 50-mile radius [ nities are finding it necessary to by the increasing cost of land- of urban centers with populations i meet or exceed all the require- filling waste, public support for of more than 100,000. The . ments, and then put additional . resource conservation, and . researchers imposed the distance i efforts into marketing strategies legislative mandates for waste constraint of a 50-mile radius ! that involve education and market . diversion - not by demand for based on the perceived limited i development. compost products. Yet if compost economic viability of shipping i The long-term feasibility of . is to become a valuable resource . farther than 50 miles. In other i commercial cornposting depends to be managed for profit, new . words, the potential use for largely upon building a market by . markets for its use must be composted products in Florida is i demonstrating safe use and estab- developed. more than 7.5 times the amount i lishing benefits, both practical and . of compost that could be . financial. Table 3-l outlines the . How Much Compost Can produced each year. . steps recommended for successful compost market development. Florida Handle? . In 1992, the average annual : . In 1996, about 23 million rate of compost penetration in i tons of MSW were collected in U.S. markets was less than 2% of i Establishing Market its potential uses (Slivka et al., i Niches and Overcoming Florida (FDEP, 1997). . Researchers estimate that, if the 1992). If the rate of compost i Barriers . organic fraction of this waste . penetration in the Florida market i New commercial cornposters stream were to be biologically follows the national trend, .i are discovering that not all com- . compost use in the state is only i decomposed, about 5.5 million . post users are created equal. Each tons of compost would be about 840,000 tons a year. requires a specific product, and generated. But key questions . Clearly, Florida has a market [ the range of quality may vary remain. Specifically, is the market development challenge, not a lack [ widely. For example, high-value capacity in Florida sufficient to . of market. . end-uses, such as a growing . use the compost produced? What . medium for landscape nurseries, is the present market capacity for . Developing a Viable require refined, mature, high . composted products? And how . Market quality composts. On the other can Florida build markets for For any type of compost to i hand, lower-value end-uses, composted products? . be marketable, regardless of .i including use as a landfill cover or . According to one study . origin, it must pass minimum : in reclamation of surface mines, . (Slivka et al., 1992), the state’s . product standards for protection : can accept any class of general- agricultural industry alone could of public health and the environ- i use compost. Experienced com- use more than 20 million tons of ment. And commercial compost i post marketers have discovered . . compost each year. And . must consistently meet the . that a low-quality compost will
COMPOST USE IN FLORIDA 15 CHAPTER 3: DEVELOPING A MARKET FOR COMPOST PRODUCTS
Table 3-1. be mature, with high organic-mat- ter content, and be free of pathogens and weed seeds. One of the most important steps in improving compost quality is minimizing the presence of hazardous materials such as heavy metals. The highest quality compost with the lowest levels of potentially harmful contaminants - particularly heavy metals and physical contaminants - is derived from source-separated organic materials that were not mixed with other materials during collection or cornposting. Following the trend in Europe, the United States is beginning to move away from mixed MSW and toward source-separated organic cornposting. (For more on quality assurance of compost, see page 21.)
Meeting the Needs of the Consumer As with all successful products in the marketplace, compost must meet the requirements of the end-user. Three factors are of particular importance to compost users: availability, cost, and quality. Compost must be consistently ’ available for end-users when they need it. If they choose to haul it themselves, it must be in an easily accessible location. The cost of compost is a composite of the . costs of the product, its trans- . portation and its application. not be marketed successfully to of compost include a dark color, : Although availability and cost high-value end-users, nor will a uniform particle size, a pleasant i . are important factors in the low-value end-user pay the earthy odor, the absence of . development of compost markets, premium price for high quality physical contaminants (such as i it appears that quality may be the compost. Yet both groups will glass or plastics), consistency, i decisive factor. It is often stated require a safe and reliable and moisture content of approxi- i that high-quality compost will product. mately 50%. Desirable chemical / always find a market. characteristics include balanced i Easing Concerns Over nutrient levels (nitrogen- Compost Quality phosphorus-potassium, and other i Teaching Consumers to Quality is a function of the i elements) and low levels of heavy i Trust Compost physical, chemical, and biological : metals, PCBs, pesticides and salts. [ Communities with commer- . characteristics of compost. In terms of desirable biological .i cial cornposting facilities have Desirable physical characteristics i characteristics, the compost must .i discovered that producing the
IGCOMPOST USE IN FLORIDA CHAPTER 3: DEVELOPING A MARKET FOR COMPOST PRODUCTS . finest product and making it i (Gallaher 1995b). First, the IFAS i physical and chemical properties conveniently available are not i team designed a set of projects to i of soils for vegetable crops, enough to entice some potential i demonstrate the absence of pesti- .i assisted in retention of water and consumers to try compost. A ’ cides in commercial composts i nutrients in turfgrass soils, and solid educational program is and is now studying the process / helped establish woody ornamen- necessary in order to substantiate for biological remediation during i tals in landscape beds. Through the benefits of using the product. cornposting. Additionally, the i the efforts of IFAS scientists, Fortunately, scientists and educa- scientists proved that they could / communities now have the educa- tors at the Institute of Food and measure compost maturity and i tional tools they need to convince Agricultural Sciences at the stability and indicate nitrogen [ potential consumers that applying University of Florida (Smith and i availability. Next, they demon- i mature compost is a beneficial Shiralipour, 1997) have done ; strated low levels of compost i and economically viable much work in communities to i toxic metal contents and the low i alternative to conventional soil build convincing arguments that i levels of these metals in crop i treatments. Q+ commercial composts are safe i parts. Finally, they established i and can be used beneficially / that applying compost improved i
COMPOST USE IN FLORIDA 17 PART 2: REGULATORY AND QUALITY ASSURANCE ISSUES/CHAPTER 4
Regulations Affecting Compost Production and Use Federal and state regulations focus on safety of compost products.
FRANCINEJOYAL FLORIDADEPARTMENT OF ENVIRONMENTALPROTECTION TALLAHASSEE,~?LORIDA
. egulations affecting compost . landscaping, erosion control, and ; State Requirements for . and its use address both . soil reclamation. Title 40 . Product Procurement product procurement . regulations can be accessed at the i R . Florida recognizes that provisions and environmental EPA web site at compost is an important . requirements. Procurement http: //www.epa.gov/epacfr40/ i component of recycling. Section provisions are aimed at . (Environmental Protection CFR .i . . 403.7065, Florida Statute (ES.), encouraging markets for recycled . Pilot). . . requires state agencies, as well as products. Environmental The EPA has also developed .: others who use state funds, to . regulations set limits needed to a series of fact sheets for its . procure products or materials classify compost so it can be used “Buy-Recycled” program. The i . with recycled content where they safely. Both federal and state fact sheet for landscaping are reasonably available. Note regulations address these issues. products, EPA530-F-97-034, i that the definition of “recycled and other information, including i content” includes composted a list of manufacturers, may be / Federal Regulations for . . materials. Further, specific . accessed at Product Procurement . provisions for state procurement . http://www.epa.gov/epaoswer/ .i of compost are found in Section The Environmental . . non-hw/procure. htm. . 403.714, ES. This section Protection Agency (EPA) guide- . lines for procurement of compost . specifies that state agencies must . . Federal Regulations for “procure compost products when are contained in Title 40 of the . . Environmental they can be substituted for, and Code of Federal Regulations, Part . 247. Only one provision specifi- . Requirements cost no more than, regular soil . cally mentions compost - . The two federal regulations : amendment products, provided . the compost products meet all Section 247.15, which concerns . concerning compost are 40 CFR i landscaping products. This . Part 257 and Part 503. Section : applicable state standards, . provision includes compost 257.3-5 contains provisions for .i specifications, and regulations.” “made from yard trimmings, the application of municipal solid [ This provision further requires the leaves, and/or grass clippings for waste to land used for growing i development of uniform product . use in landscaping, seeding or . food-chain crops. This section i specifications for procurement . . grass or other plants on roadsides . appears to need revisions to and use of compost by all state . and embankments, as a nutritious . reflect adoption of federal agencies. Copies of these . specifications may be obtained by mulch under trees and shrubs, . biosolids regulations. and in erosion control and soil . 40 CFR Part 503 addresses contacting the Florida . reclamation.” This section also . biosolids (also known as sewage Department of Management . includes hydraulic mulch products . sludge or domestic wastewater Services, Division of Purchasing . containing recovered wood used residuals). These regulations can at 4050 Esplanade Way, for hydroseeding and as an be accessed at the EPA web site Tallahassee, Florida 32399-0950. over-spray for straw mulch in mentioned above.
18COMPOST USE IN FLORIDA CHAPTER 4: REGULATIONS AFFECTING COMPOST PRODUCTION AND USE .. . TABLE 4-1 State Environmental . Quality Limits for Compost Requirements . . Two Department of . . Environmental Protection (DEP) . . regulations specifically address . . compost use in Florida, depend- . ing on the feedstock processed . into the compost product. These . are Chapter 62-709 (Criteria for . .. . the Production and Use of . . Compost Made from Solid . . TABLE 4-2 Waste) and Chapter 62-640 Classification of Compost made from Solid Waste (Domestic Wastewater Residuals), . Florida Administrative Code . . Types of Compost (F.A.C.). Copies of these rules . Made from Solid Waste can be obtained from the . . Department’s web site at: . . http://www.dep.state.fl.us or from one of the DEP District . . . Offices. . . . Solid waste . State regulations governing . the use of compost made from . .. solid waste are found in Chapter . . 62-709, F.A.C. The majority of . . this chapter contains requirements . for the compost-producing facility . . itself. However, this rule also con- .. .. tains a classification scheme and . <10mm;; organic matter>25% (fine) . use restrictions based on the type of compost produced. Compost made from solid . . waste is classified based on the . .. type of waste processed, compost . maturity/stability, the presence of . . foreign matter, the size of holes in . the sieve used to screen the com- . . * This material may not contain any foreign matter, such as glass or metal shards, of post, the organic matter content, . a size and shape that can cause injury. and the concentration of heavy . . metals. The concentration codes .* Compost maturity, for purposes i use by commercial, agricultural, used in the classification scheme of this regulation, is determined i institutional or governmental . . are identified in Table 4- 1. The . by whether the compost will i operations. In other words, the . values for “Exceptional Quality” . reheat to more than 20 degrees only restriction placed on Types B . . limits specified in the federal reg- . Centigrade (36 degrees . and C is that they cannot be . . ulation are included in this table . Fahrenheit) above ambient distributed for use by the general for comparison. temperature and the percent . public. Further, only Type B can . . Table 4-2 illustrates the classi- . reduction in organic matter. . be used in situations, such as in a . fication scheme for composted .. Classification of a compost . park, where contact with the . . . made from solid waste affects general public is likely. Compost materials. The requirements for . Type Y and Type YM are identi- . how it can be used. Only such classified as Type D can only be . . cal. However, a classification for . composts classified as Y, YM or . used at landfills or land reclama- . . “yard trash only” was mandated . A have unrestricted distribution. tion projects where contact with . . by the Florida legislature. . Types B and C are restricted to . the general public is not likely.
COMPOST USE IN FLORIDA 19 CHAPTER 4: REGULATIONS AFFECTING COMPOST PRODUCTION AND USE . . Finally, any solid waste compost i were also used in the DER's ! Chapter 2 of that document classified as Type E must be ! Residuals Rule, Chapter 62-640, i “Regulations Affecting the disposed of in a landfill unless it i F.A.C. Further, not only are the .i Beneficial Use of Residuals,” can be demonstrated that its use : classification concentrations in ! addresses residuals classified as will not harm the public or the i the Solid Waste Compost Rule i “Class A” or “Class B" under environment. Most compost i out-of-date, they are also based on i both state and federal regulations, products made from solid waste i different risk assumptions and : and residuals classified as “Class have been classified as Types Y, .i methods of calculation than are i AA” under state regulations. YM or A. the Soil Cleanup Target Levels i In summary, only biosolids . There are also restrictions : used for other reuse-type . that have received the highest regarding the total amount of i decisions within the Division of / degree of treatment for pathogen heavy metal that can be applied to i Waste Management. Given that i reduction and that also meet the soils. These restrictions, expressed / Rule 62-709.600(8), F.A.C., i most stringent pollutant limits as pounds per acre, are cadmium i stipulates that “compost shall not i specified in the regulation are - 4.45; nickel and copper - 111; i be used in any manner that will i designated as Class AA. Most or zinc -222; and lead -- 445. As i endanger public health and all of the biosolid compost these values are based on the .i welfare and the environment,” ! currently produced in Florida . most restrictive soil cation . and given the need for meets the Class AA requirements. exchange, the rule also contains a : consistency within the Division [ These residuals are subject to the provision that allows a user to .i for approving reuse projects, it is i “Exceptional Quality” limits demonstrate, through an analysis .i anticipated that rule development [ specified in the federal regulations of the cation-exchange capacity i will be initiated to update this i and the Class AA limits listed in and other physical and chemical i rule and to incorporate the Soil i the state rule. While use of characteristics of the receiving i Cleanup Target Levels for heavy i biosolids meeting these criteria . soil, that a higher application rate : metals in compost. . does not require an Agricultural . would still provide an equal i . Use Plan, nutrient content . . degree of protection. . Biosolids . information and recommended While this section discusses .: State of Florida regulations : application rates must be the current requirements, the : governing the use of biosolids are : provided to the user. concentrations for heavy metals i contained in Chapter 62-640, i in the classification scheme were i F.A.C. The DEP Division of i A Matter of Safety established in 1989 and were : Water Facilities provided a i It is important to remember based on the criteria used to i summary of regulations affecting i that the criteria established in the . . regulate biosolids prior to . residuals use in Biosolids . environmental regulations address adoption of 40 CFR Part 503 by i Management in Florida: Beneficial i product safety and not the . the Environmental Protection i Use of Domestic Wastewater . requirements of a particular Agency. These EPA standards i Residuals (DEP May 1997).* i end-user. 0
*Copies are available free of charge from the DEP's Bureau of Water Facilities, 2600 Blair Stone Road, Tallahassee, FL 32399.
20COMPOST USE IN FLORIDA PART 2: REGULATORY AND QUALITY ASSURANCE ISSUES/CHAPTER 5
Compost and Quality Assurance Compost products made with an emphasis on quality and consistency will have no shortage of uses or users.
GEORGEE.FITZPATRICK UNIVERSTYOFFLORIDA FORTLAIJDERDALERESEARCHANDEDUCATIONCENTER FORTLAUDERDALEJLORIDA
omposts are made from a ; growing medium for all crops .; quality compost. When compost changing assemblage of i under all growing conditions, i products are used as components C organic feedstocks. For this i. numerous authors have described i in growing medium mixtures or reason, there can be a great deal ! general recommendations. For : are applied directly to agricultural of variation in the chemical and [ example, for container grown i soils, a lower quality of compost physical parameters of compost. i foliage crops, Joiner (198 1) i product may be acceptable. For The quality of the compost can .: recommends the following . example, Rynk et al. (1992) influence the soil’s pH, soluble ! general parameters: bulk density: / indicate that a soluble salt salt levels, exchange capacity, : 0.30 grams per centimeter cubed .: concentration of less than 2.5 aeration, particle size distribution, i (g/cm3) (dry), 0.60-1.20 g/cm3 i decisiemen per meter (dS/m) is bulk density and water-holding .i (wet); percent pore space: 5-30%; i necessary for a stand-alone capacity. Consequently, the percent water-holding capacity: i container medium, but a value of highest quality compost products i 20-60%; pH: 5.5-6.5; soluble i less than 6.0 (dS/m is acceptable frequently compare favorably with i salts: 400-l ,000 ppm; cation- i when the compost product is to peat and other high value organic i exchange capacity: 1 O-l 00 i be used as a component in a . . substrates. The low quality meq/ 100 cm3. growing medium mixture, and a compost materials may retard i A variety of plant species are .: value of less than 20 dS/m is plant growth, and, in extreme .! sensitive to high salt concentra- i acceptable when the compost cases, may contribute to plant tions. Salts in the growth medium i product is to be used as an mortality. disrupt water uptake or directly i incorporated soil amendment. If Plant producers should be affect the physical functions of i salt levels are a concern, it is wise aware that certain quality plants. If these types of plants are i to wait until a rain or other parameters can make the exposed to high salt concentra- : watering event occurs to dilute difference between successful and tions, their growth might be : the salts. unsuccessful use of compost suppressed or seized. Therefore, i Numerous factors can .. composts with high salt influence the likelihood that any products. . concentrations could cause .. compost product will have Assessing Compost Quality .i toxicity in sensitive plant species. i sufficient quality as a rooting .. Parameters . Even a high rate of compost i medium. These include the parent Compost products are used in i application with low salt content [ material from which the compost four general ways: (1) as a stand- .i might cause injury in such plants. / product was made, the pre- alone container growing medium, ! Thus, a high quality compost ! processing and postprocessing (2) as a component in a container / physically may be low quality if / procedures to which the substrate growing medium mixture, (3) as i the salt concentration is high. ! was subjected, the amount of an organic top dressing, and i Of the four general uses for i time of active cornposting and the . . (4) as an incorporated soil .. compost, the stand-alone maturity of the compost product, . amendment. . container growing medium . the amount of inert material in Although there is no perfect i category requires the highest : the compost product, the
COMPOST USE IN FLORIDA 21 CHAPTER 5: COMPOST AND QUALITY ASSURANCE
concentration of regulated in the compost with higher solu- i elements (heavy metals), and ble salt levels were significantly i . the presence of pathological smaller than plants grown in microbiological organisms. . composts with lower soluble salts (Figure 5-l). However, both Parent Material . The composition of the ! parent material can sometimes [ influence the quality of the . Figure 5-1: Spathiphyllum ‘Mauna Loa' 40% peat, 50% pine bark and 10% grown in a compost product that had an compost product. The parent / . sand (Fitzpatrick, 1986). . average electrical conductivity of 3.9 material may affect the particle i dS/m (left) attained an average size of size, nutrient content and soluble i Other processing procedures, i 1.39 times the control. Plants grown in salts in the final product. Very i such as screening, can influence ! compost with 7.5 dS/m conductivity fine composts tend to separate .i the physical quality of the corn- i (middle) attained an average size of 1.19 and block drainage in pots, while : post products by making them times the control. Control medium more homogenous and, conse- conductivity averages 3.5 dS/m a compost with coarse, fibrous i (Fitzpatrick, I 986). properties creates a porous medi- i quently, easier for the grower to urn that facilitates drainage. For / mix and apply. Smaller plants with immature composts. These example, a compost made from i usually require composts that include biological blockage of have passed through small diame- biosolids (sewage sludge) supports .: nitrogen uptake (nitrogen-rob), ter screens. Plants grown in large more rapid growth in container- i . deformity or death of plant parts grown viburnum (Viburnum / tubs or in soil with incorporated by phytotoxic chemicals in imma- suspensum) than do composts : composts may do well with ture composts, increased mobility made from nitrogen-poor coarser material. of certain toxic elements in the materials such as garbage, urban .i soil, and similar effects (Jimenez plant debris, and stable sweepings Active Cornposting Time ; and Garcia, 1989). Many growers (Fitzpatrick and Verkade, 199 1). and Compost Product .; who use compost products store Maturity . newly delivered material for 6-12 Preprocessing and The earliest references on ! months, allowing it to decompose Postprocessing cornposting time published in the / further, as insurance against Procedures employed at the modern era (e.g., Howard and i possible phytotoxic effects. cornposting facility before and i Wad, 193 1) indicate an optimum ‘i. . after the active cornposting period : cornposting time of approxi- . Inert Material Content can sometimes influence compost i mately 6 months for mixtures ! Certain types of parent quality. For example, sludges i containing 25% of high nitrogen .! materials are often likely to frequently are stabilized and i material, such as animal manure, i contain noncompostable sub- conditioned prior to cornposting. i and 75% of high carbon material, .i stances, such as particles of glass, . If a sludge is stabilized by treat- i such as plant debris. Many . plastic, and metal objects. These ment with ferric chloride and : current commercial compost materials may be unsightly and lime, a common practice in many .i producers promise a stabilized hazardous, particularly if the wastewater treatment facilities, i end product in a much shorter inert materials have sharp edges. the level of soluble salts in the i period because of the capability If a compost is made exclusively finished compost product may be : for preprocessing, mixing, from materials such as yard trim- significantly higher than in aerating and managing moisture [ mings, leaves, or other plant compost made from sludge that [ content. Producers may feel a i debris, inert material usually is had been stabilized using a wet- .i strong economic incentive to .i not a problem. If, however, a air oxidation process. When corn- i accelerate active cornposting into [ compost is made from municipal posts made from sludges treated i the shortest possible time period. : solid waste, inert materials might . with stabilization and . If the processing time is too short, i cause problems, particularly if the .. . conditioning preprocessing . an immature compost may result. i parent materials had not been procedures were used to grow the ! Commercial plant producers who i subjected to sufficient preprocess- non-salt-tolerant container crops i purchase compost products from i ing to segregate inert materials. Spathiphyllum ‘Mauna Loa' and i such sources must be mindful of : Some states have passed environ- Schefflera arboricola, plants grown .i the negative effects associated mental regulations limiting the
22COMPOST USE IN FLORIDA CHAPTER 5: COMPOST AND QUALITY ASSURANCE amount of inert materials allowed i practiced by commercial compost temperature, 37 degrees C, is the in compost products. In Florida, : producers and monitored by optimum temperature for its state regulations mandate that i governmental regulatory growth (Oliver, 1994). However, inert materials may not exceed i authorities. the relatively small number of 2%, by weight, in compost prod- i confirmed cases of aspergillosis, ucts marketed for unrestricted i Biological Status coupled with the ubiquity of A. horticultural uses. In other areas, .i A common concern held by fumigatus in the environment, compost producers and brokers i many people relative to compost implies that the susceptibility of have developed self-regulation i use is the possible presence of humans is rather low. A recent programs. For example, compost ! pathogenic organisms. The high review of the literature indicates producers in Ohio will not sell a i temperatures reached during that humans with suppressed compost product for nursery use i active cornposting (from 130 to immune systems may become ill if the inert material level exceeds ; 140 degrees Fahrenheit) have after only minimal exposure to A. OS%, by weight (Tyler, 1993). i been shown to reduce to insignifi- fumigatus. But healthy individuals ; cant levels any pathogens that from the general population Regulated Elements i might have been present in the appear to show no significant One of the almost universal i parent material (Burge, 1983; health impacts from exposure to concerns related to compost use is : Haug, 1993). However, since this fungus (Maritato et al., 1992). the question of regulated ele- i commercial cornposting is Moreover, the average horticul- ments. The U.S. Environmental : frequently conducted on a large tural worker is exposed to many Protection Agency has issued scale, involving hundreds of tons substrates containing A. fumigatus, recommendations for the per day, questions have been such as soil, peat, sawdust, wood maximum permissible levels of : raised about whether cool spots chips, and other products. If 10 heavy metals in compost i exist in places within active com- horticultural workers do not products: arsenic, cadmium, .! post piles and whether pathogenic experience any aspergillosis chromium, copper, lead, mercury, i organisms could reinoculate the symptoms from contact with molybdenum, nickel, selenium i final product. These issues are these kinds of products, it is not and zinc. Many states have passed i normally addressed by examining any more likely that they would their own regulations, using the i representative samples of experience symptoms as a result federal recommendations as i compost products and conducting from exposure to compost guidelines. While there can be .i microbiological screenings. products. substantial differences in heavy ! Usually, the pathogens themselves Weed seeds are also a metal concentrations between i are not cultured. Rather, the concern. Shiralipour (1990) and different types of compost ! compost samples are tested for McConnell placed weed seeds in products that may be attributable i the presence of indicator plastic mesh bags, which were to the parent material and the i organisms, such as fecal coliform then placed in cornposting piles. relative level of preprocessing, ; bacteria. Indicator organism tests Exposure of the weed seeds to the overwhelming majority of i are simple, reliable and are temperatures of 150 degrees compost products available at the : required by both federal and state Fahrenheit for only a few hours present time fall well within i regulations. They serve as an was adequate to kill the weeds. federal and state guidelines .i additional safeguard to insure the (Chaney and Ryan, 1993). In fact, i maintenance of compost quality I Growing Possibilities for commercial composts in Florida i and safety. Quality Compost are required to meet these guide- ; Another microbiological issue . The potential for using lines. . of concern is the presence of the compost by agricultural interests The safety of compost i ubiquitous thermo-tolerant fungus is great. If compost products are products is further assured by the ’ Aspergillus fumigatus, a saprophyte made with an emphasis on reduction of toxic heavy metals in frequently found in decaying quality and consistency, it is likely waste streams brought about by organic materials. A. fumigatus is that use of these materials will the implementation of industrial one of the relatively few fungi continue to expand in crop pretreatment programs, as well as that can be pathogenic to production. 0 by quality control programs humans, since the human body
COMPOST USE IN FLORIDA 23 PART 2: REGULATORY AND QUALITY ASSURANCE ISSUES/CHAPTER 6
How to Produce High Quality Compost The right mix of raw materials combined with state-of-the- art technology yields a high quality end product.
PATRICK D. BYERS SOLID Wa AUTHORITY OF PALM BEACH COUNTY WESTPALMBEACHJLORIDA
compost recipe usually is a i homogenous mix. Many combi- .i introduction of ambient air and combination of organic : nations can be tried and mixes i requires no turning of the organic A materials, or feedstocks, / can be changed often, based on [ mixture once the pile is formed. capable of producing a balanced i the availability and uniformity of i By controlling air mechanically, end product, one that is nontoxic i the raw materials and the needs of ’ this process allows the use of to plants, people, and animals and .i the market. larger piles. When cornposting . that improves soil quality. . . with this method, an air plenum Common fodder for cornposting i Common Cornposting . is constructed and the organic . . includes tree bark, manure, leaves, i Systems . mixture is placed in piles on top cardboard, food waste, soiled i Cornposting technology can of the air plenum. Piles are built . paper, wastewater residuals : be as simple as using a pitchfork . as high as equipment allows, (biosolids), grass clippings, tree i and people power, or as sophisti- normally eight to twelve feet. trimmings -in effect, just about ! cated as computer-controlled, . Air is either pushed into or pulled . anything organic and biodegrad- ! state-of-the-art machines will . from the pile by a blower able in nature. A balanced recipe .! allow. Generally speaking, the . connected to the air plenum must also factor in such parame- i better the technology that is used, . system. Aerated static piles can be . ters as proper moisture levels, : the higher is the quality of the . constructed individually or in carbon-to-nitrogen ratio, particle / compost. Three types of compost extended piles. Individual piles, size, and porosity of the final i technologies currently are the . constructed all at once, allow the . . mix. :. most widely used: . processing to occur in batches. . Sometimes, it is necessary to i Windrow composting, the least . Extended piles consist of a series analyze the physical and chemical i sophisticated of the three, of cells created over the course of . . characteristics of individual . involves placing a mixture of . many days and stacked against . organic sources to help develop i organic waste materials into long, . each other to form one long recipes. Certain organic materials, ! narrow piles approximately six rectangular pile. A temperature for instance, may contain contam- i. feet high by twelve feet wide and . sensor placed within the pile . . ination from sources such as . as long as is necessary. The . works in conjunction with the heavy metals, pesticides, plastics, i compost process is accelerated by blower to control temperature and . or salts. Care must be taken to i frequent turning of the windrow . oxygen concentrations within the limit the contamination of raw .i with a front-end loader or custom pile. materials. designed machinery built for this In-vessel composting involves . After the raw materials have purpose. Turning fluffs the pile . confining the compost process to been selected, they must be .i and increases porosity of the . a variety of containers or vessels. . combined prior to cornposting. ! mixture, which helps to improve . Different in-vessel systems use a Mixing can be done in special i the introduction of ambient air . variety of methods to enhance units designed for this purpose or i into the windrow. and accelerate the compost . by front end bucket loaders that i Aerated static pile composting . process. However, each system . pick up and toss materials into a .i provides for mechanical . usually includes some method for
24COMPOST USE IN FLORIDA CHAPTER 6: HOW TO PRODUCE HIGH QUALITY COMPOST aeration, mixing, compost process been met and the desired compost more on block stockpiling, see temperature control, and contain- produced. Common test methods page 26.) . ment of odors. In-vessel systems measure the carbon-to-nitrogen . . generally are the most costly of ratio, respiration rate, moisture, . Finishing . the three major technologies pH, and weed seeds. Additional . Finishing, or post-processing, .. because of high capital construc- tests are run based on regulatory, . is usually undertaken to provide a . tion costs. Most are proprietary environmental, or end-use uniform and customized product systems that require greater requirements. . that is acceptable and marketable operation and maintenance to customers. Considerations . expenses and a higher skill level Curing . include particle size, moisture . to operate. The curing process further . content, carbon-to-nitrogen ratio, . Once a recipe has been assures that a uniform and well- . color, texture, removal of contam- established, the mixture will be digested compost is produced. . inants, and nutrient and bacterial . incorporated into the compost The length of the curing period . content. Finishing can include technology chosen, either depends on how well the organic screening, blending, introducing windrow, aerated static pile, or materials were decomposed additional nutrients and bacteria, in-vessel cornposting. These . during the digestion process and drying, and bagging. . technologies were designed to . on the ultimate end-use of the The most common finishing . accelerate the decomposition .. compost. practice is screening, which can . process of organic materials. How *. During the curing period, the significantly improve the value . these processes are managed will . compost continues to decompose and quality of compost to be dis- . . either speed up or slow down the .. but at a slower rate than that .. tributed. Screening can improve . . decomposition process, ultimately . which occurs during digestion. . the appearance, texture, nutrient . . influencing the quality and cost of . This continued decomposition . content, and carbon-to-nitrogen . the product. . improves the compost characteris- ratio of the compost, as well as . . tics and is an important part of remove unwanted materials. . Digestion . the overall cornposting process . Screening also creates fractions . During the cornposting . quality control program. . for specific end uses. . . process, microorganisms occur- . Maintaining aerobic condi- . The economics of finishing . . . . also should be considered. The ring naturally in organic materials . tions in curing piles is usually . . transform them into compost . difficult to achieve. Anaerobic . costs of finishing should be through digestion. That is, the . conditions can develop which . evaluated along with the value . . . . microorganisms break down the . may lead to odors and the . and demand for the product. . . various organic materials into . development of compounds that . simple compounds that are more . could be detrimental to plants. If Storage .. . uniform and biologically less . compost is to be distributed from . Maintaining some inventory . . active. In order to accelerate the . curing piles, it should be turned . of finished compost products is . cornposting process, these two to three times to release . usually inevitable. Storage of . organisms need an environment odors and reintroduce aerobic . compost materials may also be . . that allows them to flourish. . conditions prior to distribution. . accomplished throughout the . . The main aspects for proper . Curing can occur outside or . curing, finishing, and distribution . . management in the cornposting . under-cover. Under-cover . processes. . . process include temperature, . operations usually have fewer Storage of materials can be . aeration, and moisture control. . problems because rainfall does . under-cover, in containers, or Low temperatures are indicative . not factor into the curing process. . outside. Under-cover and . of reduced microorganism . When curing outside, considera- container storage will help . activity and could indicate a lack tion should be given to the effects prevent the effect of weather of oxygen or inadequate moisture of rainfall, which can be either . conditions on materials. . conditions. Most often, low beneficial or detrimental, . Container storage will also allow . temperatures are the result of lack . depending on the moisture . the potential for control of odors, . of oxygen. . content of the compost. Good if necessary. Outside storage . . Once the cornposting process . drainage, a solid base for . usually is the least costly but can . . is believed to be complete, testing . equipment operations, and large . be the most problematic. Outside . . should be performed to ensure . block curing stockpiles will storage considerations include the . that the cornposting goals have . maintain compost quality. (For type of storage pad, stormwater
COMPOST USE IN FLORIDA 25 CHAPTER 6: HOW TO PRODUCE HIGH QUALITY COMPOST drainage and collection, odor i use of block stockpiling. Block i materials, higher heat levels are . potential, and Mother Nature. An i stockpiling is the process of . also maintained within the . improved area that manages . making piles as high as possible i storage pile to prevent the stormwater to reduce the effects i without running equipment up on _ reintroduction of weed seeds and . on the materials is essential. . the sides of stockpiles, and as : human disease-causing bacteria. Movement of materials when the i long and wide as possible, taking : Typically, the heat generated wind direction is away from into consideration fire prevention i from the cornposting process will homes, businesses, or other i needs. Block stockpiling reduces [ also prevent rainfall from receptors is important. the surface exposure of materials i affecting the compost. Most Sizing of stockpiles to ! to outside weather conditions. .: moisture that falls on the block prevent weather conditions from i Because of the insulating stockpile will evaporate within a affecting materials includes the i characteristics of compost . few days. (I)
26COMPOST USE IN FLORIDA PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 7
The Effects of Compost on Soil When used as a soil amendment, compost can improve soil quality, help conserve watev, and may reduce the need for fertilizers and pesticides. AZIZ sH.IRALIPouR CENTERFOR BIOMASS PROGRAMS thIWRZI-YOF~ORIDA GAINESVILLE,FLORIDA
hen used in sufficient :. water-holding capacity increased Soil Erosion amounts, compost has ; by 43 percent (McConnell et al., Compost plays an important W both an immediate and .i 1993). In Gallaher’s usage of role in control of erosion by both long-term positive impact on soil : compostin a corn crop, the water and wind. The degree of properties. Compost products : composttreatment increased soil soil erosion by water depends on provide a more stabilized form of / water storage by an amount the strength of soil aggregates to organic matter than raw wastes ! equivalent to two acre-inches of withstand raindrop impact and and can improve such physical i rainfall or irrigation (Gallaher surface flow. Composts with high properties as water-holding i and McSorley, 1994). organic matter content perform capacity, water infiltration, water / In sandy soils of Florida with well for controlling erosion by content, aeration and permeabili- ; low water retention, both the water. ty, soil aggregation and rooting .! frequency of irrigation in For controlling wind erosion, depth. Compost products also agricultural farms and energy long-term research has shown decrease soil crusting, bulk consumption resulting fromwater that use of normal-size MSW density, runoff, and erosion. The i pumping should decrease asa compost is more effective than the chemical properties of soils that : result of compost application. very fine variety’ Small particle have been treated with compost i size and lightweight compost are often improved, as well, as are i. products are susceptible to wind . Soil Bulk Density soil biological activities. The use of heavy equipment erosion under arid conditions. for crop planting and harvesting Water-Holding Capacity : increases soil bulk density of Soil pH The application of compost .: agricultural soils due to Soil pH affects the availability products can markedly increase i compaction. This causes and absorption of nutrients by the water-holding capacity of ! limitation of pore spaces, which plants, particularly micronutri- soils. The increase is attributed to i decreases the aeration and water- ents. Most compost products have improved pore size distribution i holding capacity of soils. The a near neutral or slightly alkaline (Pagliai et al., 1981). Pores in the i incorporation of compost pH with a high buffering capacity. range of OS-50 micromillimeters i products in compacted soils, on Elevation of pH by compost (mm), called storage pores, hold i the other hand, decreases bulk application can bring about strong water necessary for growth of i density and increases pore absorption of and, in some cases, plants and microorganisms. i volume, the rate of water precipitation of cadmium (Cd), Most mineral soils used for : infiltration and the volume of air manganese (Mn), lead (Pb), and an agricultural purpose should i in the soil medium (McConnell et zinc (Zn) in soil particles, result- receive compost rates of 10 to 15 .i al., 1993). The reduction in bulk ing in lower accumulations of tons/acre to increase water- i density of mineral soils depends these elements in plant tissues. holding capacity by five to 10 i on the rates of compost Most agronomic crops grow percent. When 146 tons/acre of : application, the soil type, and well when the soil pH is between MSW compost was applied, the i the degree of soil compaction. 6.0 and 7.0. Addition of compost
COMPOST USE IN FLORIDA 27 CHAPTER 7: THE EFFECTS OF COMPOST ON SOIL
. to acid soils and subsequent pH . low. One reason is that release of technology used to produce the elevation reduces or eliminates . nitrogen from an organic source compost. The nitrogen- aluminum (Al) or manganese such as compost is in a mineral .. phosphorous-potassium (N-P-K) (Mn) toxicity, which can occur . form that is unavailable to plant . ratio of most composted MSW is when soil pH is below 5.5. roots. Compost nitrogen is a such that application to soils at a . (Hernando et al., 1989). valuable slow released nitrogen . rate selected to satisfy the . . The change in pH values of .* source. The rate of microbial nitrogen needs of a crop might . mineral soils by compost applica- mineralization and release of result in excess additions of tion depends upon the composted . available nitrogen from structural . phosphorus and insufficient levels . . material and the initial soil pH forms in the compost depend on . of potassium. Consequently, the and the soil’s buffering capacity. the local climate and the soil type. . use of supplemental fertilizers Incorporation of compost at rates . The first year rate may vary from . may be required to bring the . of 10 to 20 tons/acre usually . 5% to more than 75% (Sommers . nutrient levels in balance with increases pH by 0.5 to 1 .O pH . and Giordano, 1984). crop demand. As with all fertil- . unit in acid soils (Hernando et al., . Because of the warm and ization practices, the amounts of . . 1989). humid climate and sandy soils in . nitrogen, phosphorus and Florida, the rate of nitrogen potassium required for crop Cation-Exchange Capacity . . mineralization is very high; there- . production are best determined Cation-exchange capacity . . fore, plant response to compost .* by soil testing. (CEC) is the sum total exchange- nitrogen is much quicker than in . The quantity of other macro able cations that soil can absorb. . cold regions of the U.S., such as and microelements in compost Cation-exchange capacity of soils . . the northeast, with lower annual . products depends on the feed- is important in retaining nutrients rainfall and heavier soils. . stock’s type and origin and the . against leaching by irrigation Incorporation of compost . method of compost production. water or rainfall. Sandy soils tend types with high carbon-to- . Their availability is also . . to show the greatest increase in . . . nitrogen ratios will elevate the . controlled by mineralization or CEC by compost application. In a . carbon-to-nitrogen ratios of soils. compost decomposition rate. . Florida sandy soil, a compost A soil carbon-to-nitrogen ratio . Nevertheless, keep in mind that . application rate of 15 tons/acre . above 30 causes nitrogen composts are seldom used as . increased CEC by about 10% .. immobilization, or nitrogen-rob, fertilizer but as an overall soil . (Hortenstine and Rothwell, 1973). and nitrogen deficiency in plants. . conditioner. .. High rates of compost application . Nitrogen-rob occurs when micro- . (more than 10 tons/acre) organisms consume the available . Soil Microorganisms . increased soil CEC, while low plant nitrogen in the soil in order The activity of soil micro- . . rates (less than 10 tons/acre) did .. to decompose the compost. . organisms is affected by compost not change or had minimal effect Application of nitrogen as a application. Microorganisms play on CEC. Research results indicate . mineral fertilizer usually corrects an important role in decomposi- . . that application rates of 15 to 30 . this type of nitrogen deficiency. . tion of soil organic matter, which .. tons/ acre would increase the Alternatively, if cropping can be . leads to formation of humus and . CEC of most mineral soils used . delayed a few months, the : available plant nutrients. An in- for agricultural purposes by a . crease in soil organic matter con- compost will stabilize in the soil, . minimum of 10% (McConnell et correcting the problem. . tent through compost application . . al., 1993). . . can promote root activity, as spe- . Application of compost as a . . soil amendment reduces nitrogen cific fungi function symbiotically . Nutrient Content . leaching from soil. Therefore, with roots, assisting them in the . Although compost products . utilization of compost as a soil extraction of nutrients from soils. contain a considerable quantity of amendment could reduce the . macro and microelements, the . amount of commercial nitrogen . Earthworms . . nutrient content of compost prod- .. fertilizer applied and decrease the .. The population of earth- ucts is lower than commonly used possibility of nitrate groundwater worms is also increased by the . chemical fertilizers. And although . contamination (Shiralipour et al., . addition of sufficient levels of . . nitrogen (N) and phosphorus (P) . 1992b). . compost products. The soil . contents of compost are higher The nitrogen content of a . movements and tunneling by the than most agricultural soils, the composted product depends on earthworms results in enhanced availabilities of these nutrients are . the feedstock and processing aeration and water infiltration.
28COMPOST USE IN FLORIDA CHAPTER 7: THE EFFECTS OF COMPOST ON SOIL
. Soil-Borne Plant Pathogens phenomenon known as that wood waste compost was at Application of compost has antagonism or amensalism. least as effective as fungicides in been advocated by “organic” Microorganisms that produce controlling Phytophthora root rots. farmers for many years as a way substances toxic to competing In such cases, it appears that to reduce or eliminate the use of populations will naturally have a composts increase host vigor and pesticides and soil fumigants. competitive advantage. For their ability to resist infection by Indeed, suppression of soil-borne i example, a species of bacteria [ pathogens. Thus, compost plant pathogens by organics has : commonly found in compost [ application can eliminate or been well documented by some i produces antifungal volatiles : reduce the use of pesticides. 0 investigators (Hoitink et al., i (Fiddaman and Rossal, 1993). i 1993). This occurs through a / Hoitink et al. (1993) have shown !
COMPOST USE IN FLORIDA 29 PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 8
The Benefits of MSW Composts in South Florida Compost use offers an economical way to enrich the nutrient-poor soils of South Florida. DEANRICHARDSON REUTERRE~YCLINGOFFLORIDA PEMBROICEPINESJLORIDA TROPICAL TREESCAPES h&AMI,fiORIDA
outh Florida has a combina- of Second Nature MSW compost, i indications of further carry-over . tion of geographical and . produced by Reuter Recycling of i through to the third season. . S environmental conditions . Florida, was distributed over 315 .i Further, the reduction in chemical that make it unique to the conti- acres of South Florida farmlands [ dependency for crop production nental United States. Because . distributed from Florida City to i will favorably impact both the . South Florida is situated on a . Boca Raton. Two different i farmer and the environment in . formerly submerged coral shelf, . compost rates (20 and 40 tons per i the near future. All of these there is very little naturally acre, plus a control rate of 0 tons) : observations are consistent with occurring topsoil. In addition, the were applied at four different i results recorded throughout the region’s subtropical environment locations, with diverse soil types, .i history of compost production, of ensures a constant, rapid, and ranging from sandy to rocky, that / the benefits of amending native continuous degradation of any produced a variety of crops, / soils with composts. naturally occurring organics including beans, eggplant, pep- i South Florida is also home to With the exception of the pers, tomatoes, squash, zucchini, i one of the largest ornamental Everglades agricultural region, herbs, and others. In the compost i plant production areas in the this has prevented an accumula- test areas, average crop yield : United States. Tremendous tion of rich soils preferred by increases of between 28% and .i amounts of potting soils and agricultural producers. However, 44% were experienced in con- .! topsoils used in landscaping and plenty of warmth, sunlight, and trolled, large-scale research plots [ container plant production are water help compensate for the in the fields. Results also consumed in South Florida each lack of rich soils. Through the demonstrated increased nutrients, ! year. One of the basic compo- addition of relatively large decreased crop water require- .! nents of potting soils is peat amounts of fertilizers, pesticides, ments, nematode and pathogen i moss. The major topsoil fungicides, and herbicides, bounti- suppression, a reduction of the .i component used for landscaping ful good quality crops, including . impact of crop production on i is muck, a highly degraded form . vegetables, tree crops, ornamen- groundwater supplies, and a : of naturally occurring sedge peat tals, turf, and landscape materials, reduction in weed populations in i found in limited areas of Florida. can be grown successfully. . compost-amended areas. There i The normal function of this Researchers are now discovering were also indications of possible i material in nature is as a natural that the addition of composts, pest suppression in compost- i water filtration medium that . especially municipal solid waste treated areas. . cleanses surface water as it composts, can be particularly While the crop responses to .i percolates through the ground beneficial in this region. the compost applications were i into the underground aquifers crop-specific, a general trend i that make up our groundwater. Using MSW Compost in toward larger plants was observed i Removal of this sedge peat or South Florida for most crops. There were also i muck surface substrate for usage . During the 1992-1993 crop i carry-over crop benefits seen . as a potting media or topsoil year, approximately 20,000 tons / during the following season, with / effectively removes a like amount
30COMPOST USE IN FLORIDA CHAPTER 8: THE BENEFITS OF MSW COMPOSTS IN SOUTH FLORIDA
. of natural water purification the ability to act as that substitute. production using MSW composts capability, thus reducing the water i Research ongoing at the as one of the major components quality as well as the amount of i University of Florida has clearly i proved to be a successful clean water available for public i demonstrated the ability of MSW i commercial endeavor, with the consumption. Finding a suitable i compost to replace peat moss i end product having already been substitute for the muck and sedge i one-for-one in potting soils. i successfully used on numerous , peat fractions of potting medias .! Demonstration projects at a landscape projects. Project and topsoils is a critical task. It is i number of different commercial i expansions into turf production becoming increasingly clear that : nurseries verified the study ; and public works are also MSW composts appear to have results. Landscape topsoil planned. 0
COMPOST USE IN FLORIDA 31 PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 9
How Compost Benefits Citrus Crops Applying compost to Florida citrus trees may reduce disease, stimulate treegrowth and increase crop yield.
J. H. GRAHAM UNIWR!3ITYOF~ORIDA CITRUSRESEARCHANDEDUCATIONCENTER LAKElkFRED,nORIDA
itrus is the most economi- i the trunk as a result of bark i fungicides for sustained control of cally important and widely i infection, and slow decline in / soil-borne diseases is to periodi- C planted crop in Florida, .i canopy vigor and fruit production / cally apply composted organic covering about 675,000 acres in i as a result of rotting of fibrous [ materials as amendments to Central and South Florida. i roots (Graham and Timmer, suppress fungal root pathogens. Between 1992 and 1994, more .! 1992). Applications of fungicides .i Composted bark, when incorpo- than 10.3 million new trees were i control fungal infection of bark / rated into potting media, sup- planted on sandy soils, mostly i and roots and increase fibrous i presses soil-borne diseases of low in organic matter, and poor [ root density (Timmer et al., . ornamental plants (Hoitink and in nutrient exchange and water- i 1989). Although fungicides sup- i Grebus, 1994). In Australian holding capacity. Recent studies i press the pathogens, which leads ; avocado groves, root rot caused have demonstrated that compost- ./ to increased yields and fruit size i by P. cinnamomi has been effec- ed municipal solid waste of orange and grapefruit trees on i tively controlled by intensive (CSMW) and composted urban i Phytophthora-susceptible root- ! mulching with organic amend- plant debris (CUPD) may be ! stocks, yield response is often : ments and applications of gyp- beneficial to citrus by reducing / variable. Therefore, fungicides are : sum (Broadbent and Baker, 1974). the incidence of root infection, i not recommended unless . In our studies of citrus, stimulating growth of young [ populations of P. nicotianae exceed i. composted waste from different a threshold of 10 to 15 propagules i sources reduced the incidence of trees, and increasing yield and .i . fruit size in Central Florida citrus i per cm3 of soil. . root infection of citrus seedlings groves. When fungicides are used, / through direct suppression of P.. The center of the citrus they usually are applied to the soil i nicotianae in soil (Widmer et al., industry is within a 100-mile through the irrigation system two / 1998a). We conducted green- radius of a densely populated to three times over several house and field studies to area of the state, where more seasons. However, soil-applied i examine the potential for compost than 7 million people produce 5 i pesticides are prone to loss of i to suppress P. nicotianae and kg of solid waste per person per i efficacy after prolonged use and, / improve root health. day, one that holds the potential i since they are water soluble, have i Responses of Young Trees for providing the citrus industry .i the potential to leach into the i with low-cost compost. . groundwater after excessive i to Composted Municipal irrigation or rainfall (Kookna et i Waste Potential Uses of Compost ./ al., 1995). Fungal resistance to / Three trials from 1991 to . in Citrus Groves . the metalaxyl has been found in i 1996 demonstrated that mulch In citrus nurseries and groves, : Florida nurseries, raising concerns : treatments of compost are highly Phytophthora nicotianae Breda de about the long-term usage of this .i effective for growth stimulation of Haan (synonym = P. parasitica : fungicide in citrus groves young citrus trees in newly Dastur) is often an endemic root i (Timmer et al., 1998). established groves (Widmer et al., pathogen that causes girdling of i An alternative strategy to 1996,1998b). Responses were seen
32COMPOST USE IN FLORIDA CHAPTER 9: HOW COMPOST BENEFITS CITRUS CROPS for soils typical of both the ridge : interface between the mulch and i (Eichelberger, 1994), so mulches . . and flatwoods production areas. i the mineral soil, as was soil . did not increase nitrogen status of While greenhouse bioassays : temperature. The proposed major i the tree (Widmer et al., 1997). predicted that compost might / benefit of CMSW and CUPD, .i The mulches substantially suppress the pathogen (Widmer et i increased soil water availability to i improved moisture-holding al., 1998a), populations of P. i tree roots, will be further substan- [ capacity of the soil, as demon- nicotianae were either not affected / tiated by measures of soil and : strated for compost applications or even increased by compost. : plant water relations. . to other Florida crops in similar Despite pathogen activity in : . soils (Obreza and Reeder, 1994; compost-amended soils, the trees [ Responses of Bearing Turner et al., 1994). Under more performed nearly as well as those : Trees to Compost favorable conditions for water in noninfested soils and signifi- i Composted municipal waste i uptake, apparently fewer roots cantly better than those in applied as 5- to IO-cm thick i were required to take up water nonamended soils. Stem diameter : mulch layers increased the yield .i and water mobile nutrients (e.g. and root mass of young trees ! and fruit size of Marsh grapefruit : nitrogen and potassium), bringing increased 20-30% in response to i and fruit size of Valencia orange i about a 30% decrease in root post-plant treatments with surface .: two and three years after applica- i density after compost application mulches as well as incorporation i tion (Widmer et al., 1997). The i in well-drained sand soak soil. . treatments at planting. The . responses occurred in groves with i Hence, trees were able to produce growth response is best explained i marginal soils and ill-adapted i more and larger fruit instead of by increased tolerance to the i rootstocks that were predisposed i supporting the high density of disease rather than pathogen ! to damaging populations of P. : roots required by a tree in the low . suppression. Tolerance is . nicotianae. The effect of compost i water- and nutrient- holding attributed to improvement of / on root density was site-specific. i capacity sand. conditions in the root zone for : Compost increased root density of .[ In finer textured, high pH more efficient water and nutrient [ the Valencia sweet orange trees : calcareous sand, where root . uptake. on Carrizo citrange rootstock in a i density was 25-35% of that in the Operationally, the CMSW : high pH, limestone-rich soil. i sandy soil, compost apparently and CUPD is most effectively and : However, compost decreased root i worsened the soil conditions efficiently applied with a New i density of the Marsh grapefruit .i (high calcium and somewhat Holland 3000 side-discharge / trees on sour orange rootstock in i alkaline pH) that normally limit spreader as a 5- to 10-cm thick ; a low organic matter sand soil i performance of certain rootstocks mulch layer within the tree row to i (depressional sand soak). The .i like Carrizo citrange (Castle et al., cover about 80% of the root i roots in the organic mulch layer i 1993). Although the mulch layer system. Although the application i were usually lighter in color and : provided a favorable site for root rates are quite high, ranging from i healthier in appearance than : growth in calcareous soil, yield of 150-170 metric tons per hectare, ! those in the mineral soil below. i trees was not increased even after the mulch lasts up to 2 years i The mulch layer provided a zone i 3 years. before reapplication is necessary. ! of favorable conditions for growth i Thus, as for young trees, the Reduction of mulch layers to 2-5 / and function of fibrous roots. [ principal effect of the compost . cm thick decreased the tree . The increase in yield of trees .: was improvement of soil water- response and mav reauire vearly i in very sandy, slightly acid soils .! holding capacity. This condition . re-application to be effective. versus the non-response in . enhanced pathogen reproduction Current trials are designed to . calcareous, alkaline soils may be [ in the mulches because P. establish the optimum rate of related to the root density effect i nicotianae was favored by high soil CMSW and CUPD and the . of compost at the different sites. i moisture (Duncan et al., 1993). mechanism for the growth . Trees in the very well drained / However, compost appeared to . . enhancement of young citrus in !. sand soak soil treated with increase tolerance to low organic matter sandy soils. CMSW were more densely i Phytophthora root rot. The Young trees received foliated and showed little sign of .i benefits of compost for increasing adequate fertilizer and scheduled .i water stress compared to the i water and nutrient availability in irrigation so compost did not i stressed, nontreated trees. CMSW i soils low in organic matter . substantially increase their . and CUPD have slow mineraliza- : enhanced root health and uptake nutrient status. Soil water-holding i tion rates, due to their moderate i efficiency, and thereby reduced capacity was elevated at the to high carbon-to-nitrogen ratios i the impact of fibrous root disease
COMPOST USE IN FLORIDA 33 CHAPTER 9: HOW COMPOST BENEFITS CITRUS CROPS
. . recently been initiated. A Observations of Cumposted Municipal . . grower/cooperator conducted a Wastes on Florida Citrus . preliminary trial with CUPD in . 1996 and reported that the mater- . . ial was very fibrous, containing . . palm branch wastes and other . coarse woody residuals that made Sun-Ray and Southern farms are citrus grove operations of . spreading difficult. The CUPD 9,000 acres in Highlands County, Florida. During the past five . material also may have been high years, composted wastes have been applied to “sand soak" . . in salts. Thus far, residual salts in areas -sandy soils low in organic matter and pour exchange . the Bedminster CMSW have not capacity. The following are sume of the observations from these been a problem for citrus, due to applications. . the very sandy soils that facilitate . rapid leaching of salts and to the Timing . long term nature of the response These materials are best applied during a period with . . on perennial citrus trees (at least frequent rainfall. The summerperiod, particularly the month of one year to detect growth August, is best. When cumpust is applied during a wet period, a” . responses). The CUPD material far better result is acquired, . spread in 1997 did not share the . . problems experienced with the . ProdUcks . 1996 material, but this points out . We have applied municipal wastes composted with biosolids, . the need for compost to be consis- . urban plant debris campusted with biusulids, wuud mulch . tent in quality through time if . composted with biusulids, and various forms of composted . they are to be used commercially. chicken manure. The campusted wood mulch with biosolids . Another major limitation to proved to be the must consistent, and the tree response was proceeding with further trials is lunger lasting. Chicken manure proved to be a good short term the availability of a commercial green-up to carry the trees through stress. applicator with the New Holland or equivalent spreader in south- . Placement . central Florida. Two cooperators . Applications in the tree row seem to give better response than . representing about 25,000 acres of . . commercial grove land are at applications trunk to trunk across the bed, The tree row . application should be at a rate of at least twu tans per acre. . present unable to use compost . because they are unwilling to . . purchase a spreader, given the Economics . . high capital cost (approximately A consistent cumpust product is required to enable an . $lO,OOO-14,000) and the uncertain efficient application. Suffieient benefit can be achieved if the . compost product can be applied under the tree fur less than $30 . availability of high quality . compost. Nevertheless, our results per ton. . . have stimulated their interest in . further trials of local compost and probably other soil stresses (approx. 90%) with waste water sources, especially in sandy soils as well. residuals (10%) from Sevierville, . with low organic matter. . Tennessee, supplied by . Our current evaluation of the . Bedminster Bioconversion. Co- . benefits of compost used as Current Status of . Research on Citrus composted CMW has a favorable . mulches focuses on both young Some limitations in the use of carbon-to-nitrogen ratio (19: 1) and old groves in sand soak soils, compost have been encountered. and slow rate of N mineralization where citrus trees have not (Eichelberger 1994), so nitrogen responded to extra water and Foremost is the availability of a . high quality source of compost i leaching is not a concern. nutrient inputs and, thus, The local CMSW (Reuter) . probably are not manageable near the citrus industry that can i . be supplied with minimal delivery : tested in the early 1990s is no . without soil amendments. . cost. Most of the research has i longer available because the plant . Reduced rates of compost been conducted with a co- shut down. Evaluation of CUPD . produced by local municipalities . composted municipal solid waste i from another source has only in close proximity to the citrus
34COMPOST USE IN FLORIDA CHAPTER 9: HOW COMPOST BENEFITS CITRUS CROPS
i industry are now under evalua- .i tion to further quantify the .! benefits and costs of compost i applications. Although the : responses are positive, it is .i unlikely that the horticultural .; benefits will offset the high cost i of production and transport of i compost. However, if landfill .i space becomes a problem in the i.. future, the cost of production and i transport of compost eventually .i may be borne by the municipali- i ties. For example, Los Angeles .i County now pays citrus growers i to accept urban plant debris for i use in their citrus groves (J. A. .i Menge, University of California, i Riverside, personal Figure 9-1. Composted municipal waste increased growth of young Orlando Tangelo trees i communication). 0 on Cleopatra mandarin rootstock 17% (trees on right) compared to nontreated controls . (trees on left) 2.75 years after application to a typical ridge soil (Candler fine sand) at the . Citrus Research and Education Center, Lake Alfred.
Figure 9-2. Composted municipal waste (CMW) is applied to bearing citrus trees with a New Holland 3000 side-discharge spreader as a 5-10cm thick mulch layer within the . row to cover about 80% of the root system. The rate at this location ranges from 150- I 70 metric tons per hectare of treated soil area.
..
COMPOST USE IN FLORIDA 35 PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 10
Growing Field Crops with Compost The use of urban plant debris compost can increase crop yield and decrease forage cost production.
R.N. GALLAHER DEPARTMENT OFAGRONOMY thIVERSITYOF~ORIDA GAINESVILLE, FLORIDA
n Florida, tropical corn is . production. Mulching and addi- .i in some treatments over a 3-year better adapted to local soils ! tion of organic material also may : period. Significant increases were than conventional corn . increase the tolerance of plants to / also measured in soil pH, I . varieties usually developed for the i nematode damage. . extractable plant nutrients, cation- midwest. Tropical corn acreage in : . exchange capacity and water- . the southern United States Impact of UPD Compost on .i holding capacity. Tests are now . increased from about 1,500 acres i Soil Properties . underway to determine if a in 1985 to approximately 45,000 .: Large applications of UPD .; reduction in the costly input of . acres in 1991. Recent estimates : can have a major impact on . fertilizers and lime may be offset indicate a potential of 150,000 to ! improvement in soil quality, often i by the addition of compost. 200,000 acres of tropical corn ; associated with a positive crop i Soil water storage. UPD with the primary use as a late ! response. compost applied as a mulch . season planted silage crop. . Soil nutrients. The UPD resulted in the greatest amount of Sorghum [Sorghum bicolor L. i used in one study had a carbon- : soil water storage in the top 2 feet (Moench)] is another valuable i to-nitrogen ratio of approximately i of soil in three Florida UPD- silage crop that is adapted to late i 35: 1 (Gallaher and McSorley, i treated corn experiments. In one sowing conditions. In Florida, : 1995a). In order to alleviate nitro- i experiment, the UPD mulch treat- about 18% of the 142,000 acres of / gen-rob (N-rob) of crops, the i ment had 2.3 1 acre-inches more full-season corn and 5% of the compost needs to be incorporated ; water stored in the top 2 feet than . 42,000 acres of double-crop corn . into the soil a minimum of 3.5 to : the control. The estimated value is grown with conservation tillage 4 months before planting to allow ! of this soil water storage over the management. A significant equilibration to occur (D.A. : control ranged from $23.92/acre acreage of soybean (Glycine max Graetz, Soil and Water Science : to $41.46/acre, depending on the L. Merr.), cotton (Gossypium Department, University of i type of irrigation that would be hirsutum L.), small grains, forages Florida, personal communica- required to apply the same and other crops, such as tion). Nitrogen-rob does not amount of water. Use of UPD as vegetables, peanut (Arachis appear to be a major problem a mulch conserved 6 to 10% more hypogaea L.), tobacco (Nicotiana . when the UPD is used as a mulch soil water than the same amount tabacum L.) , etc., are also grown i and the required addition of of UPD incorporated, and 40% to on Florida’s infertile and highly ! nitrogen fertilizer is placed below 75% more stored soil water . . leachable sandy soils. . the mulch (Gallaher and . compared to no UPD (Gallaher . Land on which these crops : McSorley, 1995a). . and McSorley, 1994). are grown offers an opportunity i The cumulative applications i Long-term effects. All of the to recycle urban plant debris : of UPD totaled 360, 300, and 240 i soil properties, including organic (UPD, also known as yard waste) .i tons/acre for some treatments matter, nitrogen, and cation- in a safe and effective manner, i depending on the experiment i exchange capacity, were dramati- while at the same time increasing / during a 3-year period. Soil : cally increased from application crop yield and decreasing cost of i organic matter more than doubled i of UPD, the magnitude of which
36COMPOST USE IN FLORIDA CHAPTER 10: GROWING FIELD CROPS WITH COMPOST
. . was highly correlated with the . There is evidence that the addi- conventional tillage versus no- amount of UPD applied. Organic . tion of certain organic com- . tillage after soil properties have . . matter reached a peak in the third . pounds may stimulate fungal par- . been enhanced from use of UPD. year after UPD application and asites of nematodes (Rodriguez- . From this same study, it was seemed to be maintained for the . Kabana, 1991). However, the concluded that the main benefit .. next two years at the highest . most important effect of organic . of UPD against nematodes did . . UPD rates. Soil nitrogen amendments on plant-parasitic . not appear to be reduction of . . appeared to peak one year after . nematodes may be the reduction nematode populations, but . . . . the last application of large . of populations from toxic byprod- . improved growth and tolerance of . . amounts of UPD. Extractable ucts of decomposition. Ammonia . host plants in nematode-infested nutrients were also increased by and urea were shown to suppress sites. Sweet corn yields were . application of UPD (data not several nematode species in tests, . equal for UPD treatments both . . shown). Data seemed to fluctuate and the decomposition of some . conventional tillage-incorporate somewhat for phosphorus, forms of organic nitrogen can . and no-tillage-mulch, and both . perhaps as a result of more than . release byproducts which are . gave yields superior to the con- . . one mechanism, such as farmer toxic to nematodes (Rodriguez- . ventional tillage control without . fertilization, soil fixation versus Kabana, 1986). The most effective . UPD (Gallaher and McSorley, . . extractable, and crop uptake. It is . of these amendments are those 1995b). clear that large quantities of . with low carbon-to-nitrogen ratios . . phosphorus was applied in UPD. . that can release ammonia into the . Response of Corn to . .. Extractable potassium peaked . soil (Rodriguez-Kabana, 1986). . UPD Compost . . . . the year of the last application of . Regardless of the mechanism . There was a consistent trend . . UPD then declined. This may be .. involved, the addition of organic . for corn forage yields to increase consistent with what would be amendments may serve to allevi- . . . as the cumulative total UPD . . expected, since large quantities of . ate some of the adverse effects on application rate increased. A high potassium are taken up by a corn . crop growth caused by plant- .. correlation was found between crop, potassium is highly leach- . parasitic nematodes. Of the . corn forage yield (Table 10-l) and . able in a sandy soil, and it is . plant-parasitic nematodes found . all of the soil property variables . . somewhat replaceable on . at some UPD Florida field corn . presented. These data also show . . exchange sites even though, in . research sites, Paratrichodorus . that the effects of UPD applica- . . this case, the cation-exchange . minor was significantly decreased . tion, at the high rates used in . . capacity had increased. . from application of UPD these studies, had a long-term . Extractable calcium and . (McSorley and Gallaher, 1996). benefit on soil quality and crop magnesium appeared to peak and . Other nematodes, such as yield, extending well beyond the be maintained, or in the case of . . Meloidogyne incognita, were not last year of UPD application calcium, may have even increased . consistently affected by compost . (1994). It has not yet been deter- . . after the last year of UPD . applications. Effects of the high . mined how long these benefits . . applications. .. carbon-to-nitrogen-ratio compost . will persist. . . The cation-exchange capacity . on these agricultural sites may . Increased corn forage yields . seemed to peak one year after the provide beneficial effects only . from use of UPD ranged from 2.5 . . last application of large amounts . after several years of UPD ton/acre to 6 ton/acre, valued at . . of UPD. Continued soil analyses . application. . 34/ton (based on 30% dry . of these plots in future years . In another study, transplanted . matter), depending upon the . . would be useful in determining . seedlings of squash (Cucurbita . experiment. Increased yield was . . the duration of the impact that . pepo) and okra (Hibiscus esculentus) . positively correlated with the . UPD has on continuing changes . and the use of conventional . increased soil organic matter, . . in soil variables. tillage incorporated UPD . improved soil fertility conditions, . . appeared to result in best yields .. and greatly increased soil water . Compost Effects on . (Gallaher and McSorley, 1995b). . storage capacity. Mulched . . Nematodes . These results were based on limit- no-tillage UPD treatments .. The increased nutrient levels . ed data and a limited time for soil consistently had greater amounts . and water-holding capacity of . properties to be impacted by . of stored soil water compared to soils amended with compost may .. compost and to translate into the conventional tillage- increase plant tolerance to nema- . crop response. Totally different incorporated UPD treatments tode damage (Watson, 1945). . results may be found between (Gallaher and McSorley, 1994).
COMPOST USE IN FLORIDA 37 CHAPTER 10: GROWING FIELD CROPS WITH COMPOST
. 0 ton YWC/a . yields increased. If the cost of 120 ton YWC/a UPD and its transport to the field were to be as much as $2/ton, . then the advantages of the UPD . . essentially disappear, and cost . . would exceed the price of silage at the farmers storage pit (Hildebrand et al., 1997). The challenge for future researchers and policy-makers is to balance societal and economic benefits. 0 . . . .
. . . 0 . 1993 1994 1995 1996 1997 . YEAR .. . Table 10-l: Compost Use and Corn Silage Yield. Corn silage yield from use of yard waste . . compost (YWC) on Haufler Farm, Gainesville, Florida (values of YWC are in ton /acre . cumulative from applications in 1992, I993 and 1994.
In California, test blocks showed $322 per acre (30 tons silage per that when the organic matter level year) from double-cropped corn is raised through large scale for silage was reported by addition of organic amendments, Gallaher et al. (1991). impressive changes take place If nutrients from biodegrad- (Woolley, 1995). When the able solid waste were used instead organic matter is doubled to 4%, i of fertilizer to replenish soil there is a four- to five-fold . nutrients removed by the corn increase in water retention, . silage crops, the net return would resulting in a 10% to 25% . increase to $536 per acre, a net . . reduction in irrigation required i. $2 14 per acre increase. If UPD . in a normal rain year. Further i provided these nutrients on 5,000 research is required to determine : acres of double-cropped corn what periodic level of re-treat- i silage, a fertilizer savings of over ment with compost will sustain : $1,000,000 would be realized the these benefits. . first year alone. These savings were calculated . . Economics of Cornposting i based on the assumption that, . In 1989, Florida produced an i because of societal benefits, average of 16 tons per acre corn i municipalities wish to recycle silage on nearly 20,000 acres of i biodegradable solid waste on corn silage harvested. Economic i farmland and, therefore, there benefits from reduction of i would be no cost to the farmer for . fertilizer inputs and increased i materials, hauling and spreading. . water conservation to corn silage ! Purchase and transportation costs alone could amount to $200 per might result in no financial acre. For example, depending on : advantage to the farmer for the nutrient concentrations and : disposal of or use of UPD on . ratios in composted waste . sandy soil farmland, even though materials, a typical net return of .i soil properties and corn forage
38COMPOST USE IN FLORIDA PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 11
Use of Composts on Florida’s Vegetable Crops When used with care, compost can give Florida’s vegetable crops a boost.
MONICAROZORES-HAMPTONANDTHOMASA.OBREZA UNIVERSITY OFFLORIDA/INSTITIJTEOFFOODANDAGRICULTWULSCIENCES SOUTHWEST FLORIDARESEARCHANDEDUCATIONCENTER IMM~KALEEJL~RIDA
lorida is a major vegetable- : particle size, presence of weed . degree of plant injury is directly producing state, with 418,000 : seeds, and odor (Ozores- . related to compost maturity and acres under cultivation each i Hampton, et al. 1998a). .. soluble salt content. Optimum F . . year (Florida Agricultural chemical and physical parameters . Statistics Services, 1997). Sandy ! . for composts that might be used . Pros and Cons of Applying soils used to grow Florida , in vegetable crop production are vegetables have low native Compost to Vegetable . listed in Table 1 l-l. fertility, so they require relatively i Crops . In Florida, soil application of high fertilizer inputs. However, .i When compost is incor- immature compost consistently minimizing fertilizer leaching or porated into soil, observed . resulted in “N-immobilization,” runoff has become important as a benefits to crop production have where available forms of . result of potential negative been attributed to improved soil inorganic N were converted to environmental impacts. If water physical properties. Compost . unavailable organic N followed and fertilizer conservation could usually contains large quantities . by growth inhibition of vegetable be increased, grower input costs of plant-available micronutrients crops such as beans, corn, . and negative environmental . (Ozores-Hampton et al., 1998a). . peppers, tomatoes, and squash effects could potentially decrease. : However, soil improvements are (Kostewicz, 1993; Gallaher and In recent years, composts i mainly attributed to increased . McSorley, 1994; Bryan et al., produced from a wide range of .i organic matter concentration 1995). When immature compost waste materials have become ! rather than increased nutrient . is applied and a crop is planted available in Florida on a large i availability. (Gallardo-Lara and immediately, growth inhibition . . scale (Smith, 1995). While . Nogales, 1987). Significant . and stunting may be visible for 40 . environmental regulators are .: quantities of nutrients . to 60 days. When using compost . mainly concerned about trace : (particularly nitrogen, phos- . with C:N ratios higher than 25 or metal concentrations in compost, : phorus, and micronutrients) . 30, N fertilizer should be applied, . growers have different interests / become bioavailable with time as . or planting delayed for 6 to 10 . once compost has passed . compost decomposes in the soil. . weeks to allow the compost to regulatory health and safety i Amending soil with compost stabilize in the soil (Obreza and standards (Ozores-Hampton et : provides a slow-release source of Reeder, 1994). al., 1998a). From a commercial [ nutrients, as opposed to mineral Research on vegetable . vegetable grower’s point of view, : fertilizer, which is usually water- . compost utilization in Florida compost quality is judged by its / soluble and is immediately has established several potential . moisture and nutrient available to plants. applications: soil amendments, concentration, pH, soluble salts, : Crop injury has been linked soil-borne disease suppression, organic matter concentration, ; to use of poor-quality compost, biological weed control, carbon-to-nitrogen (C:N) ratio, i such as that from early stages of alternative to polyethylene mulch, water-holding capacity, bulk : the cornposting process (Zucconi and as a transplant media. density, cation-exchange capacity, ! et al., 1998a). The type and
COMPOST USE IN FLORIDA 39 CHAPTER 11: USE OF COMPOSTS ON FLORIDA’S VEGETABLE CROPS
TABLE 11-l Physical properties of compost used in vegetable production*.
Passes 1 inch screen
Uncomposted materials disseminate weeds
Z FDACS, 1995. YG.I = (% seed germination x root length growth in % of control)/ 100.
Compost as a Soil response than separate applica- as nutrient concentration or N Amendment . tion of either material alone. . mineralization rate, and soil . Amending Florida soils with i One concern of using . physical and chemical properties. composted materials such as i biosolids or MSW-based . . biosolids, MSW, and urban plant : composts is the possible presence . Soil-borne Disease . debris (UPD) has been reported i of unwanted elements in the . . Suppression to increase crop yields of bean, ’ compost and their uptake by The colonization of compost black-eyed pea, okra, tomato, crops. Compost that does not . by beneficial microorganisms squash, eggplant and bean, water- meet EPA 503 standards for during the latter stages of melon and tomato, corn, and bell metals concentration in biosolids cornposting appears to be pepper (Bryan and Lance, 1991; cannot be marketed and is thus responsible for inducing disease Ozores-Hampton and Bryan unavailable to be applied to . suppression. Compost does not 1993a, 1993b; Ozores-Hampton agricultural land. Research in . kill the pathogens that cause et al., 1994b; Obreza and Reeder, Florida on tomatoes and squash . disease as fungicides do. Instead, . 1994; Gallaher and McSorley, grown on calcareous soil where . compost controls the pathogens 1994). In calcareous soil, biosolids, MSW, and co- . by keeping the beneficial micro- . . application rates of biosolids composted biosolids-MS W that . organisms active and growing. compost as low as 3 to 6 met the 503 standards were Therefore, pathogenic agents tons/acre resulted in crop yield applied showed no trace metal either will not germinate or will . increases for tomatoes, squash, accumulation in the edible plant * remain inactive (Ozores-Hampton . and beans (Bryan and Lance, parts (Ozores-Hampton et al., . et al., 1994a). 199 1; Ozores-Hampton et al., 1994b and 1997). In Florida, few experiments 1994b). In sandy and calcareous . If all of Florida’s organic in vegetable crop production . soil, MSW compost application fraction of solid waste was under field conditions have rates of 40 tons/acre resulted in converted to compost, it could investigated the use of compost crop yield increases for bean easily be assimilated by the in controlling soil-borne (Obreza and Reeder, 1994). Florida vegetable industry. If only pathogens. Municipal solid waste (Figure 1 1- 1) Contradictory crop 20 tons/acre of compost (fresh . (MSW) was incorporated into response results were found when weight) were applied to each of . calcareous soil in Dade County at 36 and 72 tons/acre and a compost with low nutrient the 418,000 acres of vegetables . content was compared to a annually grown in Florida, 8.4 . compared to an untreated control . traditional fertilizer program. million tons of compost could be . (Ozores-Hampton, et al., 1994a). . However, combining such recycled each year (Smith, 1994). . A two-crop rotation of bush compost and inorganic fertilizer The actual rate and frequency of . beans and southern peas were has generally been more effective compost use should be deter- seeded. Bean emergence and yield in producing a positive plant mined by compost properties such i were improved by 25% in the
40COMPOST USE IN FLORIDA CHAPTER 11: USE OF COMPOSTS ON FLORIDA’S VEGETABLE CROPS
Figure 11-1: MSW compost application rates of 40 tons/acre (top) as compared with the no compost application (bottom) on watermelon. Comvost-treated plots yielded 22.35 tons/acre compared with 16.15 tons/acre in control plots with no compost.
. compost treatment compared to i Hampton et al., 1998b). Weed and the presence of phytotoxic i compounds (fatty acids) in the the untreated control. Ashy stem .i seed germination inhibition by blight of bean caused by burial under mulch is due to the i immature compost (Ozores- Macrophomima phasolina was : lack of growth-promoting factors i severe in areas with no compost i such as light, temperature, or : application, but was almost moisture. Chemical effects of ; completely eliminated where : phytotoxic compounds (volatile i MSW compost had been applied i fatty acids and/or ammonia) in i (Figure 1 l-2). MSW compost i compost can decrease weed seed : . reduced the damage by . germination. In Florida, a water i Rhizoctonia root rot in southern i extract of 3-week-old UPD and ; . pea considerably compared with i immature MSW compost . the untreated control. In the areas / decreased germination of several i with no compost application, ! perennial and annual weeds in i severe infections caused plant i petri dishes (Shiralipour et al., i stunting and premature death, i 1991). Under field conditions, i with significant yield reduction. i application of immature 4-week- [ old MSW compost at 3 inches (45 i Biological Weed Control : ton/acre) or greater thickness :. Weed growth suppression is i completely inhibited weed an important attribute of surface- i germination and growth for 240 i applied mulch. An organic mulch ! days after treatment in vegetable i i : Figure 11-2: MS W compost suppresses weeds by its physical crop row middles. Inhibition of application rates of 72 tons/acre presence as a surface cover, or by i germination or subsequent weed ! (front) nearly eliminated ashy stem the action of phytotoxic corn- : growth may be attributed to both ; blight, compared with the no compost pounds contained in it (Ozores- .i the physical effect of the mulch i application (back) on bush beans.
COMPOST USE IN FLORIDA 41 CHAPTER 11: USE OF COMPOSTS ON FLORIDA’S VEGETABLE CROPS
Compost as a Transplant Medium : Checklist for Compost The vegetable transplant industry relies on peat moss as a Utilization on Vegetable Crops major ingredient in soilless media (Vavrina and Summerhill, 1992). 1.Use of immature compost can cause detrimental effects on plant Peat is an expensive, non- growth. H&h C:N ratio compost can result in N-immobilization if it is renewable resource. In Florida, below 25:1 to 30:1. We recommend assaying compost for the presence of alternative soilless media has been phytotoxic compounds using a cress seed germination test. In this test, a investigated to grow tomato, compost sample is saturated with water, and the extract is squeezed from cucumber, bell pepper, and citrus the sample. A portion of the extract is used to moisten filter paper in a seedlings (Vavrina, 1994; Roe and petri dish, on which mess see& are placed and allowed to stand fur 24 Kostewicz, 1992); Stoffela et al., hours. The germination index (GI) is measured as GI = [(% cress seed 1996). Seed emergence and germination x root length in % of the control)100]. If GI is less than seedling growth was similar to 60, allow about 90 days between the time of compost application and traditional peat:vermiculite media planting of the crop, or apply nitrogen fertilizer. For example, if cress when peat was partially replaced germination and root length on compost was 40% and 1 inch, and the with compost. Negative growth control 80% and 2 inches, respectively, therefore we obtained a 50% cress effects were reported when the seed germination and 50 % root length as % of the control Thus, the medium was 100% compost, GI = 25, indicating immature compost. An alternative measure is to especially when immature, continue composting the material to maturity before it is applied. unstable compost was used or the 2. Most vegetable crops are sensitive to high soluble salts, especially compost did not have adequate when they are direct-seeded. We recommend measuring the soluble salts fiber content to assure a desirable concentration of a saturation extract. If the electrical conductivity (EC) bulk density. 0 is below 6.0 dS/m, no salt toxicity should occur. If the EC is above 6.0 dS/m, the amended soil should be leached by rain or irrigation with water before planting seeds (only a few crops can tolerate this salt level).
3. Lack of equipment to spread cumpust in vegetable fields is a concern. We encourage cumpust facilities to play an active role in developing spreading equipment. Source: Ozores-Hampton et al., 1998a.
Hampton et al., 1998a). Similar major production cost to Florida : weed reduction was obtained with i growers. Therefore, utilization of i mature MSW compost (100 i composted waste materials in : tons/acre) in row middles of bell : combination with living mulches i pepper compared with an . in a bell pepper production untreated control, but herbicide : system was investigated (Roe et i provided improved weed control : al., 1992, and 1993a). Traditional ! over mature compost (Roe et al., i raised beds were covered with : 1993b). polyethylene mulch, MSW, wood .i chips, or biosolids-UPD co- . Alternative to Polyethylene i compost (100 tons/acre), and bed .: Mulch sides were either planted with a i Polyethylene mulch regulates : St. Augustine grass living mulch / soil temperature and moisture, ! or not planted. Bell pepper yields : reduces weed seed germination : were higher on compost mulch i and leaching of inorganic plots than on unmulched plots but i fertilizer, and is a barrier for soil j lower than on polyethylene- : fumigants. Removal and disposal i mulched beds. of polyethylene mulch has been a :
42COMPOST USE IN FLORIDA PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 12
Compost Uses for the landscape and Nursery Industries
High quality compost frequently compares favorably with GEORGE E. FITZPATRICK AND peat as a growing medium for Florida's nursery and DENNISB. MCCONNELL ENVIRONMENTAL HORTICULTURE DEPARTMENT landscape plants. thIVERSITY OF FLORIDA GAINESVILLE, FLORIDA
f all the different agricul- ; spectrum of nursery crops, from i reviewed published studies on tural uses for compost i flowering annuals (Wootton et al., i compost use in a wide variety of 0 products, use as a growing : 1982) to container-grown tropical i crops, including nursery crops, medium component in orna- ! trees (Fitzpatrick, 1985). In a i and reported significant increases mental crop production frequently i demonstration project conducted ! in crop productivity. receives high priority because of i in 1979-1980 at a commercial i Unlike other applications of . the relatively high value of . nursery in southern Florida, a compost in agriculture, the stand- nursery and greenhouse crops and ! number of container-grown alone container medium category the continual cultural requirement i ornamental species grew to requires the highest quality of for organic matter for rooting i marketable size significantly faster compost. One example of the substrates (Slivka et al., 1992; i than plants grown in a growing influence of compost quality on Tyler, 1993; Tyler, 1996). Every / medium composed of 6 peat: 4 compost performance as a time a container plant is sold, the i sawdust: 1 sand, by volume component in a horticultural rooting substrate is sold with it, .i (Fitzpatrick, 198 1). One of the growing medium is the level of necessitating the need for new i species tested, dwarf oleander total salts in the substrate. The potting mixtures to start new crop ! Nerium oleander, grown in IO-inch i level of soluble salts in composts . production cycles. .. diameter containers for 5 months, ! made from sludges stabilized with . The attractiveness of . averaged approximately 1.25 : ferric chloride and lime may be ornamental crops as outlets for i times larger when grown in the / considerably higher than in compost product marketing does i compost mixture as compared to i compost made from sludge that . . not come without cost, however. i the control (Figure 12-1). . has been stabilized using a wet-air Since the plant’s root system is in i Moreover, compost products have i oxidation process. One study direct and continual contact with i been successfully used in field .i compared the use of these two the compost product, any con- i nurseries as soil amendments to : types of sludges for growing the cerns regarding compost quality .i increase productivity in various non-salt tolerant container crops are most acute with container i tree species (Gouin, 1977 - Spathiphyllum Mauna Loa and crops. Plant producers must keep i Gouin and Walker, 1977). Schefflera arboricola. The plants in mind that the way compost [ Numerous other research grown in the compost with higher products should be used is not .i studies and reviews have been soluble salt levels were signifi- necessarily the same way that nat- i published on how compost cantly smaller than plants grown ural humus products, such as i products can be used to improve i in composts with lower soluble . peat, are used. . production of nursery crops. i salts. However, both compost Sanderson (1979) reviewed a large i products resulted in plants that Using Compost for i number of published studies and i. were significantly larger than Ornamental Crop . reported significant increases in i plants grown in a control medium . Production productivity across a wide variety ! consisting of 40% peat, 50% pine Compost materials have been .; of nursery crops. More recently, / bark and 10% sand (Fitzpatrick, used successfully to grow a wide i Shiralipour et al. (1992a) . 1986).
COMPOST USE IN FLORIDA 43 CHAPTER 12: COMPOST USES FOR THE LANDSCAPE AND NURSERY INDUSTRIES
.; used without fertilization, .i especially in fast growing trees i such as schefflera (Brassaia .: actinophylla) and West Indian i mahogany (Swietienia mahagoni) i (Figure 12-2) (Fitzpatrick, 1985). i In this same study, slower i growing trees, such as pink i tabebuia (Tabebuia pallida) and .i pigeon-plum (Coccoloba .i diversifolia), grown in biosolids i compost and irrigated with i secondary treated sewage effluent, i grew at rates that were not i significantly different from rates i observed in trees grown in a peat, i pine bark and sand medium .i fertilized at normal nursery crop Figure 12-1. Dwarf oleanders (Nerium oleander) grown in I O-inch diameter containers .i levels. Apparently, the levels of for 5 months in a trial conducted at a commercial nursery averaged I.25 times larger .i nitrogen (N) in the effluent than plants grown in a control growing medium comprised of the nursery’s standard i (average 6.8 mg/L, SD=5.8) were mix of 6 peat:4 sawdust:1 sand, by volume (Fitzpatrick, 1981). .i sufficient to augment nutrients .i provided by the compost medium i in the slower growing trees, but i not in the faster growing species. . . [ Expanding Horizons Careful attention to growing .i medium characteristics can allow i faster and more economical i production of ornamental crops. .i Since nursery crops have a .i recurring need for a growing .i medium as each growing cycle is .i completed, compost marketers .i have the opportunity to develop .i products that can be very ; attractive to ornamental plant i growers. Provided the compost .i products are made with emphasis Figure 12-2. West Indian mahogany Swietenia mahagoni grown in compost alone with i on quality, it is likely that use of no fertilization and irrigated with well water (second from right) did not achieve growth i compost materials will continue comparable to trees grown in a peat, pine bark and sand medium fertilized at normal i to expand in nursery crop nursery crop rates (control [right]). Trees grown in compost medium with no fertilization and . .i production. 0 irrigated with sewage effluent (secondfiom left) grew larger than trees grown in peat, pine . bark and sand medium, with no fertilization and irrigated with secondary effluent. Compost . medium did not supply sufficient nutrients in fast growing tress such as mahogany and schef- flera. In slower growing trees, the compost and effluent supported growth rates comparable to the rates observed in the control (Fitzpatrick, 1985).
Growers also should be aware . i provide all of an ornamental that while many compost i crop’s requirement. For example, products contain significant levels i in one study in which tropical of certain plant nutrients, they i trees were grown in containers, rarely contain these nutrients in i the compost products did not sufficient concentrations to i provide sufficient nutrients when
44COMPOST USE IN FLORIDA PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 13
Use of Compost on Turfgrasses JOHN L. CISAR Compost may help build better turfgrasses on some UNIVERSITY OF FLORIDA 148,000 acres of golf courses in Florida. FORT LAUDERDALE RESEARCH AND EDUCATION CENTER FORT LAUDERDALE, FLORIDA
GEORGE H. SNYDER UNIVERSITY OF FLORIDA EVERGLADES RESEARCH AND EDUCATION CENTER BELLE GLADE, FLORIDA
‘here are more than 5 million from uses of composts in other . received the compost incorpora- . homes with turfgrass lawns . turfgrass situations and from . tion. In greenhouse studies, in Florida, and more than . other regions. Detailed, specific, . leaching of several organophos- 1,300 golf courses, an increase of proven recommendations for phate insecticides was reduced by . more than 15 percent since 1994, . compost use on golf courses in compost addition, and the . The average Florida golf course is . Florida cannot be given at this addition of compost did not 114 acres in size. Thus, more than . time. . increase leaching of nitrate or 148,000 acres in Florida are dedi- . Of the research that has been phosphorus (Cisar and Snyder, cated to golf courses. Golf course conducted on golf courses in 1995). . maintenance expenditures average . Florida, most has related to using . Compost clearly provides . $3,585 per acre annually. Money . compost as a soil amendment to . much needed plant nutrients for . generally is available and will be . improve the native sand soils . turfgrass growth, which is .. spent by golf courses for mainte- . which generally are droughty, . reflected as increased uptake of .. nance practices that are proven to . infertile, and have little capacity nutrients by turfgrass grown in . . be beneficial. . to retain nutrients and other agro- . compost-amended soils (Table 13- .* chemicals. We have consistently . 1). In one compost source study Beneficial Effects of demonstrated that overall turf- that is still underway, the positive . . Composts on Turfgrasses . grass quality, in terms of visual . turfgrass growth and visual turf- in Florida . appearance and vegetative density, grass quality effect of compost . . Numerous articles recently ,. is improved by the incorporation incorporation has been observable . have discussed the potential use . of composts in the root zone at for more than 2.5 years. . . of compost on golf courses. Most . rates up to approximately 30% by We believe the major nutri- . . of these focus on using compost volume (Cisar and Snyder, 1995; . tional benefit of the compost is . . for topdressing, and some discuss . Snyder and Cisar, 1996). In these due to the quantity of nitrogen it . . the use of golf course-generated . studies, various municipal com- contains, which is slowly released . organic waste as compost feed- posts were spread over the soil . to the turfgrass over time. In this stock. However, there is little doc- . surface at a depth of approxi- . regard, some sources of compost umentation of actual compost use . mately two inches and incorporat- contain more nitrogen than on golf courses, other than as . ed by rototilling to a depth of . others. Those that are amended mulch around ornamental plant- . approximately six inches. with biosolids have analyzed ings. The use of compost as a soil Particularly in the months higher in nitrogen than composts .. amendment during golf course . shortly following compost appli- . made exclusively from urban . . construction is rarely discussed. . cation, drought resistance has plant debris, and turfgrass growth . . Because of a lack of scientific . been observed (Cisar and Snyder, has been greater in soils amended . . studies aimed specifically at utiliz- . 1995). The time following a rain- . with such materials (Snyder and . . ing compost in golf courses in fall or irrigation event until turf- Cisar, 1996). The composts Florida, discussions on the subject . grass wilting was observed to be contain other nutrients as well, will be based upon inferences increased in those plots that but some fertilizer may be needed
COMPOST USE IN FLORIDA 45 CHAPTER 13: USE OF COMPOST ON TURFGRASSES
TABLE 13-1 United States Golf Association Effects of Compost on Nutrients in Turfgrass (USGA). The specifications allow for inclusion of organic matter in the form of sphagnum peat, but the use of other materials is not . recommended. It may be possible . to substitute compost for sphag- num peat, but any such mixture . should be analyzed in the labora- . tory before use to confirm adher- ence to USGA-specifications for 20/5/93 the root zone mix. For this rea- son, no blanket recommendation can be made for the use of com- post in greens construction.
Topdressing Routine soil application on the surface of greens (topdressing) to control thatch and increase surface smoothness and ball roll on mature and new golf course l **, *, and ns represent P<0.01, 0.05, and P>0. 10, respectively. greens is an essential golf course cultural management operation. . Topdressing adds a thin layer of TABLE 13-2 . using compost on golf courses, . soil, usually no more than 1/8- Relationship Between Turfgrass . but provided few examples of its Topdressing Rates and Depth. . inch depth at the surface of the use or specifics about using turf, after which it is incorporated Application Application compost on various portions of by mechanical and physical rate depth the course. Thus it appears that . action with brushes or mats. At . the task still remains to combine . this rate, approximately 0.4 cubic . existing data on the benefits of . yards of topdressing per 1000 ft2 . . compost to turfgrass with a . of surface area are required consideration of the various . . (Table 13-2). Frequency and rates . possible uses on a golf course in i . of topdressing are based on . order to suggest methods and ; targeted use. In Florida, top- . . markets for compost uses on golf : dressing is applied to bermuda- 1.0 I 0.32 . . courses. . grass as often as bi-weekly. Light to provide a balance of nutrients Golf courses can be compart- i rates of topdressing are preferred with respect to the nitrogen mentalized into four main sectors: / for quality greens (Beard, 1982). content of the compost. In this greens, tees, fairways, and roughs. ! Topdressing rates range from 0.05 regard, potassium may be On an area basis, fairways and : yards per thousand square feet for relatively low in some composts. roughs account for more than 90 .i . . well-performing greens with . percent of the golf course. . . minimal thatch to 0.4 cubic yards Potential Uses of Compost . Although greens and tees per thousand square feet for . Amendments in Golf Turf . constitute only a small portion of i bermudagrass greens with a . A number of articles have . the entire area, they receive a vast : thatch problem (Beard, 1982). majority of the overall mainte- : appeared in golf course trade . Greens in Florida generally . nance dollars and effort expended i magazines in recent years encour- . . comprise 6 to 8 thousand square . . aging the use of compost on golf . on the course. feet each. courses. However, in most cases, . Topdressing materials should . little information is presented that . Greens Construction i closely match the texture of the . specifically describes the use of . Modern greens generally are i existing soil medium if soil root compost. For example, Wilkinson constructed according to rigid i zone modification is not the goal. (1994) listed many benefits of specifications delineated by the : Soil layering should be avoided as
46COMPOST USE IN FLORIDA CHAPTER 13: USE OF COMPOST ON TURFGRASSES this reduces water and air move- ; required for maintenance, and Cornposting Golf Course ment through the profile. Thus, : irrigation might be reduced Wastes topdressing may not consist i somewhat. Using golf course leaf blade purely of compost. Instead, i clippings and other plant-derived topdressing materials generally i Fairways materials as an organic amend- consist of sand- and soil-sized : Fairways constitute the bulk ment to topdressing has been an particles, in addition to organic .i of the golf course acreage. “in-house” practice of some . materials (Beard, 1982). Compost probably could be used superintendents for a number of Furthermore, organic matter .i beneficially in fairways during years. However, there has been lit- addition to topdressing is an area i construction, with incorporation tle scientific study to base recom- of controversy. Some experts i in the surface soil at rates of 10 to mendations for using such recommend pure sand for top- i 20% by volume, and up to 30% in materials. Potential problems dressing of greens, as sufficient i well drained areas. Bunkers and arising with incorporating organic organic matter is found in thatch i fairway mounds often are matter from such sources include (McCarty and Elliott, 1994). On i droughty and difficult to manage, introduction of pathogens, weeds, the other hand, Adams and Gibbs i and compost use in bunker and nutrient-rob from poorly (1994) recommend topdressing i mound construction might be . composted materials, source applications with a low amount of ’. especially valuable. Utilization of inconsistency, and play interrup- . organic matter to dilute the resid- compost in fairway construction tion from poorly sized organic . ual organic matter and to avoid . could aid in “grow-in” and main- materials. Golf courses may also .. the increased surface hardness . tenance, reducing the required be limited by low storage capacity . from pure sand applications. . amount of fertilizer and possibly and availability of composted Regardless of the philosophy . water for at least several years. . topdressing and labor support to on the benefits of including adequately prepare the top- organic matter in topdressing, Roughs . dressing materials. Companies many golf course superintendents Roughs are second in area . that could conduct the compost routinely apply topdressings that . only to fairways. Compost . operation at the golf course, and have organic matter mixed in as . incorporation into areas devoted . . vendors who could supply an additive to improve nutrient . to roughs could be especially . . composted topdressings, as and water retention. A number of useful, since fertilization and . needed, could fill this marketplace organic materials have been used irrigation probably could be niche (Ostmeyer, 1993). in soil mixtures, with peats being . reduced. In all but poorly drained . .. For golf courses that want the most popular. Composted leaf areas, compost incorporation at to do on-site preparation of blade materials generated by the . rates up to 30% by volume should composted topdressings, few course also have been used. be permissible. . guidelines exist. The dry soil . . Following current management . topdressing mix should be sieved practices, more compost would be The Role of Compost in . . to remove large objects and may utilized in topdressing for greens . .. Disease Management on . require fumigation to kill off . than for any other portion of Golf Courses . pathogens, weed seeds, and course, because topdressing is not Intensively managed golf undesirable vegetative propagules routinely used on the remainder . . (Beard, 1982). The organic matter . greens are particularly exposed to of the course. Greens are mowed . stresses caused by plant diseases. fraction portion should be sized . very closely, so compost used in . to avoid segregation after . In recent years, alternative topdressing must be very fine, and methods of disease control, application to the turf surface. . not contain fragments of metal, including the use of composts and According to Beard (1982), the glass, and plastic. final preparatory step for the . biological control agents, have . been suggested (Nelson, 1992). topdressing mix should be composted for a period of up to Tees . The mechanism of control is . Tees probably could be . thought to be through suppression eight to ten months to regenerate constructed with 10% by volume of disease by either a direct effect soil flora and fauna. Composted of microorganisms in the compost topdressing should be stored in a compost, or perhaps somewhat . . on the pathogen or from more well-ventilated shed and be more, and there would be an . agronomic benefit for the grass. .. favorable soil conditions which sufficiently dry at the time of application (Beard, 1982). 0 Initial “grow-in” likely would be . encourage soil microflora faster, less fertilizer would be . diversity, leading to suppression.
COMPOST USE IN FLORIDA 47 PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 14
Compost Use on Forest lands Using compost on Florida’s forest lands may be an acceptable means of recycling organic residuals.
H. RIEKERK DEPARTMENT OF FOREST RESOURCES AND CONSERVATION thIVERSITY OF FLORIDA GAINESVILLE, FLORIDA
n he recycling of composted . the silvicultural municipal solid . was about 75%. The carbon-to- . . residuals through forest . waste (MSW) compost utilization . nitrogen ratio of the compost on . . lands is generally beneficial . study was to investigate the effects . the seedling site was 30, on the . . because of increased growth of . of composting on water-holding . forest site 34, and of wood chips timber with a low health risk for . capacity, soil chemistry, soil/ 58, while the moisture contents . the remote human food-chain. . ground water quality, and tree . . . were 33%, 26% and 45%, respec- . . Composted waste utilization on . survival and growth (Riekerk, . tively. The urea had 46% nitrogen, . forest lands has been documented 1995) and to demonstrate . the lime 28% calcium, and the . nationwide and in Florida as an . conservation of water by . mixed fertilizer 10% each of . . acceptable alternative for waste . increasing the soil retention . nitrogen, phosphorus and . . recycling (Cole et al., 1986; . capacity with amendments of . potassium. The compost on the . . Riekerk, 1986; Jokela et al., . organic waste products. . cleared site was disked into the . 1990). Recycling the slow-release . The sites were in the Austin soil and then planted with slash . . materials carefully and sparingly . Cary Memorial Forest near the . pine seedlings, but that on the . . on the highly absorptive porous University of Florida in a cleared . forested site was only top-dressed . forest soils maintains acceptable . area of sandy soil with a 3 ft deep . between tree rows to avoid root . . ecological conditions and runoff . water table, and in a six-year old . damage (Figure 14- 1). . . water quality. The added organic slash pine (Pinus elliottii) planta- . Compost, surface soil, . matter increases the absorptive . tion forest on poorly-drained soil. . soil/ground water sampling and . capacity and decreases the acidity . This site design was chosen to . analysis lasted only for a year, but . . of Florida’s forest soils. These . evaluate the effects of leaching . periodic tree measurements were . . processes, in turn, increase the . depth on groundwater . continued over 5-l /2 years. . . retention of heavy metals against . contamination, and of weed . leaching into the water table . competition on tree survival. Water-Holding Capacity . (Fiske11 and Pritchett, 1979). Five-row plots within each . The data from the seedling . site indeed showed reduced soil site received on average a low . Compost Utilization in a (59), medium (96), and high (127) . bulk density, which increased . . Slash Pine Plantation . . field soil water content of all . dry ton/acre of compost during . Forest . . treatments. The high-rate compost . the fall of 1992. Half-length 50 ft . . application significantly increased This project built upon a . plots received 100 lb mixed . previous study of the benefits of . saturated water-holding capacity . fertilizer + 100 lb urea +200 lb . in the seedling site. compost application to a slash . lime (nutrient-only) or 68 dry pine flatwoods site prior to . ton/acre wood chips (carbon- Similar results were reported planting. In that case, composted only) to separate their combined for MSW compost applications MS W application nearly doubled effects in compost. The nutrient up to 20 ton/acre in a young the yield of wood without mea- . application with wood chips aver- slash pine plantation (Bengston . surable adverse effects (Jokela et . aged about 50% of the low com- and Cornette, 1973). . al., 1990). The main objectives of . post rate, and that with fertilizer
48COMPOST USE IN FLORIDA CHAPTER 14: COMPOST USE ON FOREST LANDS
. Soil SurFace Chemistry i nificant rise in phosphorus by the . reduced nitrate-nitrogen levels The compost treatments i high-rate compost. In contrast, under the wet, organic-rich and the addition of similar rates of neutral pH levels of the high-rate increased the pH, mineral and ; . organic matter levels, as could be ’ compost to agricultural soils . compost, but significant nitrogen expected from the relatively high under laboratory conditions . immobilization may have been reduced water-extractable phos- . application rates. Similar results . the dominant process under the have been reported by others phorus levels by fixation (Graetz, wood chips with a very high car- (Fiske11 and Pritchett, 1979; 1994). bon/nitrogen ratio of 58 (Graetz, Fiske11 et al., 1979). Post-treat- Because of an unexpectedly . 1994). The relatively low nitrate . ment organic matter analyses ; high phosphorus level in soil . nitrogen level in soil water under . showed a 1.5-2.0 fold increase in i water from the control plot of the . wood chips of the forest site also organic matter for the high corn- / forest site, significantly increased . suggested nitrogen immobiliza- post treatments with up to 3% i phosphorus levels could not be tion, but nitrification is low in the organic matter in the topdressed i demonstrated for the treatments. . acid soil of this site (Burger, . forest soil. . However, the phosphorus level in . 1979). The wood chips with the high i soil water from the control of an . The high pH and conductivi- .. . soluble phosphorus content . earlier study on the site was about . ty levels under the compost layers increase the phosphorus in the .: 0.24 ppm (Burger, 1979) suggest- were generated by the significant- surface soil as much as it was : ing significant increases by the . ly increased amounts of potassi- . expected. The high levels of phos- i treatments. . um and calcium in soil water, . phorus in percolating soil water The highly variable nutrient which in turn were exceeded by .i . suggest significant leaching, but : levels of soil water were increased . those of water-soluble laboratory . the lack of a treatment response i mostly by an initial flushing . compost extracts. The soil/ of the phosphorus level in ground i effect, with the exception of ground water ratio for copper water (at both sites) may have i nitrate-nitrogen in the high-rate . (Cu) was similar to that in a . been caused by mineral and ! compost and wood chip plots of . loamy soil column leaching study biological fixation in the sodic i the seedling site. A comparison of . where the process of Cu mobility . the average nitrate-nitrogen levels . was associated with the soluble horizon (Fiske11 and Pritchett, .i . 1979). in water-extracts with those in soil Cu supply from compost rather water showed much lower ratios . than being complexed by dis- . under compost than wood chips, . Soil and Ground Water . solved organic matter that was . Quality . suggesting nitrification of the trapped by the subsoil All treatments increased : large amount of water-soluble (Giusquiani et al., 1992). . phosphorus levels in soil water of / ammonium-nitrogen in the com- . The chemistry of soil water . the seedling site, including a sig- i post. Denitrification apparently may be important for tree nutrition; however, that of ground . water is of environmental . . concern. While soil water under . . all the compost treatments had . . higher levels of nutrient elements . than the control, only the high- . . rate compost application . . generated ground water quality . levels that exceeded accepted . .. standards for a significant time . interval. The main contaminant was nitrate-nitrogen, as was . . . expected from its ionic mobility . and its documentation by . previous studies (Riekerk, 1986). . . . . Tree Survival and Growth . The addition of nutrient-rich MSW compost obviously has a . . fertilizer effect on plant growth.
COMPOST USE IN FLORIDA 49 CHAPTER 14: COMPOST USE ON FOREST LANDS
The effect of compost on average- .i density with age (Jokela et al., Compost application rates for tree volume was a 42% increase i 1990). tree growth improvement can be by high, 33% by medium and i . as high as 130 dry ton/acre, but 25% by low applications, while i Recommendations for transport and application costs that by wood chips was 33% and ! Compost Application on . and increased tree mortality fertilizer was 29% after 66 i Forest Lands makes a medium rate of 100 dry months. The latter responses sug- i The information from this ton/acre more effective. In gest that about half of the corn- i study suggests that for a large- addition, established limits of post effect was derived from the i scale application, better methods environmental water quality added organic matter (water-hold- are required for a more even standards in Florida restrict the ing capacity) and half from distribution of the compost over application rate for poorly- improved nutrition. Tree the site. Top dressing in an drained sandy pine flatwoods to mortality in the fertilizer plot existing pine plantation is feasible 400 lbs/acre of nitrogen per year, created a plot volume 63% higher with a straight-walled live-bottom or about 100 dry ton/acre of than that of the control while the wagon, but incorporation may compost every five years. Earlier others grouped around 37% more. damage the roots. Application of trials in a plantation establish- This compares to about 70 per- i paper-mill sludge pellets with a ment showed that optimal growth cent of biomass weight after 16 i centrifugal fertilizer spreader has could be realized at 100 tons/acre years in an earlier study, which is ; been done operationally in or less. 0 in part due to increased wood / northeast Florida.
50COMPOST USE IN FLORIDA PART 3: AGRICULTURAL USES FOR COMPOST IN FLORIDA/CHAPTER 15
Reclamation of Phosphate Mine lands with Compost The phosphate mining industry annually reclaims an average of 4,000 to 5,000 acres of mine lands in Florida, making it a viable market for compost products. Jm RAGSDALE
SANITATION DEPARTMENT CITY OF ST. PETERSBURG ST. PETERSBURG, FLORIDA
n he phosphate industry in i the old lands at a rate of $4,000 found on phosphate lands are its Florida produces more than i an acre for mined-out areas and ability to provide a low cost 75 percent of the United i $2,500 an acre for clay settling i: source of wetland seeds for plant States’ supply of phosphate. The i areas and other land forms. Of i establishment and its ability to industry is concentrated in five i the 87,000 acres of old lands retain moisture during the dry southwest Florida counties that i mined before 1975, almost half season. include Hillsborough, Polk, remain to be reclaimed. Some of the problems Hardee, Manatee and Desoto, experienced by the industry with where over 90 percent of Traditional Use of Organic the mining of muck are: 1) it is Florida’s phosphate is mined. In i Material by the Mining not uniform in particle size, 2) it 1996, the mining industry began .i Industry may contain nuisance plant seeds, reclamation at a 100 percent : In Florida, the level of 3) while stockpiled, its moisture equivalency that requires one acre organic matter required by the : level should be maintained to to be reclaimed for every acre Department of Transportation for .! preserve seed and to avoid wind mined. The phosphate mining establishment of vegetation is 1 ! disbursement, and 4) muck may industry on average reclaims percent. Soil found on mined i be found with a relatively low between 4,000 and 5,000 acres a phosphate lands usually has less i organic content level (around 20 year of mine lands in Florida. than one half of one percent ! percent .) organic matter. The mining indus- i Wetland creation involves the Statutory and Economic try manages its soil to recover its ; additional expense of soil Considerations organic content. Topsoil found in / recontouring of elevation to The cost to reclaim phos- i overburden is set aside for future : create hydrological conditions phate land is between $3,000 and i use. Peat is seldom available. needed to form wetlands. Another $8,000 per acre. Earth-moving i Muck is the primary material associated cost to the mine com- contributes the largest single i used, but its availability varies. pany is the processing of muck expense. Mining reclamation i Muck is found in wetland areas that includes excavation, transfer, costs for “old-lands” - those i with depths ranging from a few [ stockpiling and application. mined before July 1, 1975 - are .i. centimeters to several meters. As i Blending of recycled urban subsidized by the State part of a permit to mine wetlands, i plant debris with muck in order to Comptroller from the Minerals ! mining companies typically are : obtain biological diversity of seed Trust Fund, which is funded by a i required to remove and stockpile i is one option for future field trials. phosphate severance tax. After i. muck prior to mining and to use / To use recycled urban plant debris . that date, state statutes required / it later to reclaim wetlands. . organic material in wetlands miti- mandatory reclamation of mine i At the present time, the pri- .i gation projects, it should have the lands by the phosphate industry i mary reclamation activity where i following parameters: 1) be free of . itself. . organic material may be required : weed seed, 2) have a preferred pH The Comptroller reimburses i is in the re-creation of wetlands. / range between 5.0 to 6.3) contain the industry for reclamation of ./ The main reasons to save muck a particle size that will not float,
COMPOST USE IN FLORIDA 51 CHAPTER 15: RECLAMATION OF PHOSPHATE MINE LAND WITH COMPOST
4) have a level of maturity that tion projects. The industry is now tailings and clay settling. . releases nitrogen, 5) have an . exploring the development of a Sheet cornposting offers a organic content range between . low cost means of land applica- large-scale processing potential . . but requires, as a precondition, 35 and 65 percent. . tion of organic material that does . not exceed its present reclamation the availability of a large tract of . land and ample time. The sheet Mining Industry% Past and . costs per acre. . Present Use of Recycled . cornposting process involves the . Future Uses and Benefits formation of windrows with Organic Material of Recycled Yard Waste specially designed delivery trailers The industry has had limited Organic Material containing live bottoms. The exposure to the use of urban . The lands with the greatest windrows are strategically plant debris organic material. . . potential for use of urban plant positioned for the future even Historically, there have been a few . . debris organic material as a soil . distribution of material when small scale field experiments . . . amendment are the more sterile . spread to a depth of one or two where urban plant debris organic . . upland areas that receive sand . feet over large land areas. At material was used in demonstra- .. . . tailings and the clay settling areas, . two feet of depth, the sheet tion projects. It has been used in . . where the organic content is less . cornposting process accelerates turf establishment on quartz sand . . . than one half of one percent. The . decomposition by creating a slopes and on phosphogypsum . successful establishment of turf in . lower temperature than found in stacks. . upland areas acts as a buffer to fil- . windrows. This provides a The industry now requires . . ter storm water runoff that broader range of microbial that organic material be particle . . activity while improving the avail- . reduces water turbidity in wet- size-reduced, managed for weed . .. lands. Organic material also can ability of oxygen and retaining seed and delivered by motor . . . be substituted for the application . rain water that accumulates on carrier to the reclamation site. . . . of clay that is placed in sand, . the bottom six inches. At a future Mining activity in Florida is . .. where it is used to improve the . date, the remainder of the decom- located on the northern edge of . cation-exchange capacity and . posed material is cut into the soil the southern climate zone, which moisture retention. . prior to plant revegetation. is subject to invasive, nuisance . The establishment of . The significance of the scale plants. For this reason, a weed . . vegetation aided by the use of of operation is illustrated by the seed-free material is required. . . organic material will improve the . fact that, at two feet of depth, an Another concern by the industry . . . properties of soil structure and acre will hold 1,000 tons and a is the availability of a sufficient . reduce soil erosion. The addition . 100-acre tract will hold 100,000 quantity of acceptable material to . . of organic material aids the soil’s . tons. meet its reclamation needs. . . . physical and chemical properties . Sand dam. The phosphate . .. . by improving cation-exchange . industry has reduced its depen- . . The Industry’s Conversion . dence on deep well water and . capacity, increasing water-holding . to the Use of Recycled . capacity, reducing the acidity in . now relies heavily on recycling . Organic Material . soils, and providing plant nutri- the water used to transport the . . The most important indicator . ents. Soil biological properties are . slurry mix of mined ore. It also . of successful reclamation is plant . improved by reintroduction of a uses water as a medium to . performance. State regulations microbial population in the soil. separate non-phosphate material. . allow one year for revegetation Sheet cornposting. State . Quartz sand is removed from the . and one year for vegetative . regulations regarding the duration . matrix of ore material and is used . establishment. Soil that has been .. of time allowed for completion of to construct dams found in an . mined needs improvement to . reclamation is determined by the elaborate network of retention . support vegetation. Addition of . size of the land and the character . lakes and canals used to remove . . organic material results in . of the soil. On a 400-acre tract of . clay and reuse the water. increased soil fertility and the land, the state normally allows a Quartz sand is low in ability of vegetation to become . total of six years, including four . nutrients and organic matter and . . established and self-sustaining. . years for earth-moving, one year . has poor water retention qualities. . . The use of recycled urban plant . for revegetation and one year for To comply with the requirements . debris organic material by the . plant establishment. A longer of turf establishment on dams phosphate industry will increase reclamation period is allowed for constructed of sand, the industry . following successful demonstra- . upland soils that contain sand applies a mixture of bahia and
52COMPOST USE IN FLORIDA CHAPTER 15: RECLAMATION OF PHOSPHATE MINE LAND WITH COMPOST
. bermuda seed to the dam face . ing to further stabilize the slope. raise the soil pH while also wall. The industry reports that, . Phosphogypsum stacks. This improving moisture and nutrient within three years, sympathetic . is another area where the mining retention qualities to the soil. . weed growth inundates the seeded , industry may be able to use large Roadway stabilization. . areas. Contributing to this amounts of urban plant debris Phosphate mines use long condition is the four-to-one slope . organic material. Very little pipeline routes to transport the of the dam and the mid-range . research is available using urban mined ore slurry to benefaction . size of the quartz sand particle . plant debris as a medium amend- plants where the phosphate rock that allows water to percolate, ed on slopes. Here the objective is is separated. The pipelines require . creating arid conditions for turf to create soil conditions that service roads and the routes cross . establishment. . improve the establishment and .. areas high in sand content. Yard The industry is interested in . survival of turf grass on phospho- waste organic material provides a experimenting in a field trial over . gypsum stacks and that help temporary stabilization material a two-acre area of a sand dam . remediate the effluence impact of . for the road surface while face. Urban plant debris organic .. surface water runoff that may providing texture to the sand and material will be blended with the . include soluble salts, fluoride and reducing dust. . sand at 0, 30 and 50 percent . radon. Erosion control. There are ratios and applied to one foot . The establishment of turf on watershed areas from rainfall that . depth. The year-long demonstra- . gypsum stacks has proven difficult erode upland areas. Recycled . tion project will attempt to show . as a result of a very acidic pH urban plant debris mulch has that, as the material decomposes, range between 3.0 and 5.0. been effective in reducing erosion . it will provide moisture and nutri- . Composted urban plant debris when placed in a row or small ent retention needed to assure . organic material with a higher pH berm across the top of the area extended turf establishment, help- range of around 8.0 is expected to subject to erosion in upland areas. 0
COMPOST USE IN FLORIDA 53 GLOSSARY
Biosolids: The solid material / concentrations that are regulated i the soil against erosion from rain- removed from wastewater after because of the potential for i fall (adapted from Cornposting domestic sewage has been toxicity to humans, animals, or / Council, 1994). processed at wastewater treatment [ plants. Trace elements include .i plants. Also known as “residuals” [ copper, nickel, cadmium, lead, i Nitrogen Immobilization or “sewage sludge” (adapted from ; mercury, and zinc if present in i (N-rob): A condition in which Biosolids Management in Florida, ! excessive amounts (Cornposting / microorganisms in immature . 1997). . Council, 1994). compost consume the available plant nitrogen in the soil to Compost: “Solid waste that has .i Humus: A complex amorphous .i decompose the compost. undergone biological decomposi- / aggregate, formed during the .i Allowing the compost to stabilize tion of organic matter, has been i microbial decomposition or for a few months before planting disinfected using cornposting or i alteration of plant or animal i or applying nitrogen as a mineral similar technologies, and has been : residues and products synthesized ; fertilizer usually corrects the stabilized to a degree which is ; by soil organisms; principal con- .i problem. potentially beneficial to plant .i stituents are derived of lignins, j growth and which is used or sold .i proteins, and cellulose combined : Organic Matter: Any carbona- for use as a soil amendment, arti- i with inorganic soil constituents; [ ceous material (exclusive of . ficial top soil, growing medium .i dark or black carbon-rich . carbonates) of animal or amendment or other similar uses” i; relatively stable residue resulting i vegetable origin, large or small, (Rule 62-701.200(21), Fla. from the decomposition of : dead or alive, consisting of hydro- . Administrative Code). organic matter (Cornposting . carbons and their derivatives. . Council, 1994). . Contamination: Unwanted . Pathogens: Organisms or micro- . material. Physical contaminants . Macronutrients: Nutrients used organisms, including bacteria, . can include sharps, metal . by plants in high quantities. mold, fungus, virus, and protozoa . fragments, glass, plastic, and . capable of producing an infection . . Mature Compost: Material that : stones; chemical contaminants . or disease in a susceptible host. can include trace heavy metals . has gone through the windrow or .i Measures to control pathogens and toxic organic compounds; . in-vessel process for “sanitation” i include industrial hygiene, . biological contaminants can . and has been sufficiently cured for ! effective design and operation . . . stability so as not to introduce i for biodegradation of pathogen include pathogens. In excessive . amounts, a contaminant can . phytotoxic acids. Mature compost / nutrients and adequate and become a pollutant (adapted from will not deplete soil nitrogen to i uniform aeration and tempera- support additional biological Cornposting Council, 1994). . i ture/time to assure pathogen . . decomposition but will be i destruction (adapted from . Curing: The last stage of . beneficial to soil and plants ! Cornposting Council, 1994). cornposting that occurs after grown in the amended soil ! . most of the readily metabolized . (adapted from Cornposting ! Phytotoxins: Toxins that may . material has been decomposed or . Council, 1994). endanger plant viability or . stabilized. It provides additional . functionality. (Cornposting . biological stabilization . Micronutrients: Nutrients ! Council, 1994). .; (Cornposting Council, 1994). required by plants in small . quantities but toxic at high levels, i Screening: A production step to . . Feedstock: Organic materials that ; including boron, chlorine, copper, ! mechanically classify materials by can be composted. Commonly- i iron, manganese, molybdenum, i size through the use of screening . used feedstocks include grass : and zinc. . equipment. clippings and other urban plant ; Mulch: A soil surface cover used i Soil Conditioner: (Soil debris, biosolids and municipal .i . solid waste. to retain moisture by retarding : Amendment) A soil supplement evaporation, discourage weed / that physically stabilizes the soil, Heavy Metals: A group of growth, stabilize temperatures by ! improves resistance to erosion, metallic elements with insulating the soil, and stabilize [ increases permeability to air and
COMPOST USE IN FLORIDA 55 water, improves texture and i the soil and can cause nitrogen .i Windrow: An elongated resistance to crusting, eases i deficiency in the soil mix and be .i formation of urban plant debris cultivation, or otherwise improves i detrimental to plant growth, even i where the dimension of soil physical quality (Cornposting .i causing death of plants in some i construction, the particle size, Council, 1994). .i cases (Cornposting Council, ; and the manner of rotation ; 1994). i provides a state to control Stability: A level of biological ; temperatures. Windrows have a activity in a moist, warm, and .! Urban plant debris: Grass i large exposed surface area which aerated biomass sample. Unstable .i clippings and other yard i encourages passive aeration and biomass consumes nitrogen and ; trimmings. i drying. oxygen to support biological activity and generates heat, .i Water Table: The upper surface carbon dioxide, and water vapor. i of ground water (Cornposting Unstable, active compost i Council, 1994). demands nitrogen if applied to
56COMPOST USE IN FLORIDA REFERENCES
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58COMPOST USE IN FLORIDA . Soils and Composts Used in ! and soil water content. J. Soil Sci. . Inc., Englewood Cliffs, NJ. Florida Field Test Sites. Florida i 41:73. . . Water Conservation and Compost i . Jokela, E.J., W.H. Smith, and . Utilization Program, Subproject i Hernando, S., M.C. Lobo, and A. . S.R. Colbert (1990) Growth and . C. (Ed.) W.H. Smith, IFAS, : Polo (1989) Effect of the applica- . elemental content of slash pine 16 University of Florida, Quarterly ’ tion of municipal refuse compost . years after treatment with garbage . Report April-June 1993: 49-5 1. on the physical and chemical . composted with sewage sludge. properties of a soil. Sci. Total . J. Environmental Quality . Graetz, D.A. (1994) Reactivity of Environ. 81/82:589-596. . 19:146-151. . Soils and Composts Used in ., . Florida Field Test Sites. Florida Hildebrand, P.E., R.N. Gallaher, . Kelly, S.D. (1994) Sites, plastic Water Conservation and Compost and R. McSorley (1997) Corn for- . bags and compost markets. Utilization Program, Subproject i age yield and cost of silage pro- . BioCycle September 1994: 5 3. . C. (Ed.) W.H. Smith, IFAS, i duction from use of yard waste . University of Florida, Quarterly ; compost. pp. 238-244. In: R.N. . Kostewicz, S.R. (1993) Pole bean Report July-September 1994: i Gallaher and R. McSorley (Eds.). . yield as influenced by compost . . 95-96. .. Proc. 1997 Southern Conservation .. yard waste soil amendments. Proc. .. . . Tillage Conference for Sustainable . Fla. State Hort. Soc. 106:206-208. .. Graetz, D.A. (1996) Compost i Agriculture. Special Series SS- . . . maturity/stability measures . AGR-60, the Cooperative . Kostewicz, S.R. and N.E. Roe. . important to nitrogen and toxic ! Extension Service, Inst. Food & (1991) Yard waste and poultry . metal availability and accumula- ‘i Agr. Sci., Univ. of Florida, . manure composts as amendments . tion in crops. In: A Market . Gainesville, FL 32611. . for vegetable production. . Development Program for Compost in i . HortScience 26:6. . Florida, Annual Report. Pp. 38-54. i Hoitink, H.A. J., R. Inbar, and . Center for Biomass Programs, i M.J. Boehm (1993) Compost can . Kluchinski, D., J.R. Heckman, J. . . University of Florida. . suppress soil-borne diseases in . Mahar, D.A. Derr, and F. Kelly . container media. Am. Nurserym. . (1993) Leaf Mulching: Using . Graham, J. H., and Timmer, L. i 178(16):91. . Municipal Leaf Waste as a Soil . W. (1992) Phytophthora diseases i. . Amendment. Special report by of citrus. Pp. 250-269 In: Plant i Hoitink, H.A.J. and H.M. Keener . the New Jersey Agric. Exp. .. Diseases of International Importance. : (1993) Science and Engineering of . Station, Rutgers Univ., Trenton, Vol. III. Diseases of Fruit Crops. : Composting: Design, Environmental, . NJ. J. Kumar, H. S. Chaube, U. S. ! Microbiological and Utilization . Singh, and A. N. Mukhopadhyay, i Aspects. Renaissance Publications, . Kookna, R. S., H. J. Di, and L. eds. Prentice-Hall, New Jersey. [ Worthington, OH. . A. G. Aylmore (1995) A field . . study of leaching and degradation Hauck, F. W. (1981) The impor- ! Hoitink, H. A. J. and M. E. . of nine pesticides in a sandy soil. tance of organic recycling in the i Grebus (1994) Status of biological ! Aust. J. Soil Res. 33:1019=1130. .,; agricultural programmes of devel- [ control of plant diseases with . . . oping countries. In: Organic . composts. Compost Sci. Util. .. Lisk, D.J., W.H. Gutemann, M. . Recycling in Asia, pp. 17-28. ! Spring: 6-l 2. . Rutzke, H.T. Kuntz, and G. Ghu FAO/UNDP Regional Project ! . (1992) Survey of toxicants and . RAS/75/004. Project Field i Howard, A. and Y.D. Wad (1931) . nutrients in composted waste . Document No. 20. Food and i. The Waste Products of Agriculture, . materials. Arch. Environ. Contam. Agriculture Organization, United i Their Utilization as Humus. Oxford .. Toxicol. 22: 190-l 94. . . Nations; Rome, 184 pp. . University Press, London. . . . . Maritato, M.C., E.R. Algeo and Haug, R.T. (1993) The Practical ! Jimenez, E. J. and V.P. Garcia. . R.E. Keenan. (1992) Potential . Book of Compost Engineering. Lewis ! (1989) Evaluation of city refuse .. human health concerns from . Publishers, Boca Raton, FL. i compost maturity:a review. . cornposting. BioCycle . . . Biological Wastes 27: 33(12):70-72. 115-142. . Haynes, R.J., and R.S. Swift .! . . (1990) Stability of soil aggregates [ Joiner, J.N. (Ed.) (198 1) Foliage .. McCarty, L.B. and M.E. Elliott . in relation to organic constituents .: plant production. Prentice-Hall, . (1993) Best Management Practices
COMPOST USE IN FLORIDA 59 for Florida Golf Courses. Greens i of bell peppers and eggplant and Horticulture 3: 115-l 30. Construction. University of i (Abstract). HortScience 28:463. Florida, IFAS EH Publication i Parsons, L.R., and T.A. Wheaton . SP-141. . Ozores-Hampton, M. and H.H. i (1994) Compost Utilization and Bryan. (1993’0) Municipal solid .i Water Conservation Test McConnell, D.B., A. Shiralipour, .i waste (MSW) soil amendments: / Demonstration with Citrus. and W.H. Smith (1993) Compost Influence on growth and yield of ! Florida Water Conservation and application improves soil proper- snap beans. Proc. Fla State Hort. i Compost Utilization Program, . ties. BioCycle 34(4):6 l-63. Soc. 106:208-210. . Subproject B2, (Ed.) W.H. Smith, . IFAS, University of Florida, McSorley, R., and R.N. Gallaher Ozores-Hampton, M., H.H. i Quarterly Report July-September (1996) Effect of yard waste com- Bryan and R. McMillan. (1994a) i 1994: 5-7. post on nematode densities and Suppressing disease in field crops. i maize yield. Supplement to Journal : BioCycle 35(7):60-61. Riekerk, H. (1986) Waste of Nematology 28(4S):655-660. .i Utilization on Forest Lands in Ozores-Hampton, M., B. Schaffer, i Florida. University of Florida, Nelson, E.B. and C.M. Craft H. H. Bryan, and E.A. Hanlon. i IFAS, Cooperative Extension (1991) Introduction and establish- i ( 1994b). Nutrient concentrations, i Service, Circular 734: 12 p. ment of strains of Enterobacter ! growth and yield of tomato and i cloacae in golf course turf for the ! squash in municipal solid waste i Riekerk, H., and L.V. Korhnak biological control of dollar spot. i amended soil. HortScience . (1995) Compost Test Plant Disease 75:510-514. 29:785-788. . Demonstration in a Slash Pine Forested Watershed; Final Norcini, J.G., and G. W. Knox .i Ozores-Hampton, M., E.A. i Report. In Florida Water (1993) Use of MSW Compost in i Hanlon, H. H. Bryan, and B. i Conservation /Compost Utilization Establishment of Live Oak i Schaffer. (1997) Cadmiun, copper, i Program, (Ed.) W.H. Smith, Planted in the Landscape. Florida i lead, nickel, and zinc concentra- i University of Florida, Center for . Water Conservation and Compost i tions in tomato and squash Biomass Programs, IFAS, Utilization Program, Final Report ! growth in MSW compost- Gainesville, FL: l-20. . of Subproject B.4.b., (Ed.) W.H. . amended calcareous soil. Compost i Smith, IFAS, University of . Science and Utilization 5(4):40-45. / Riekerk, H., and M.C. Lutric Florida, Quarterly Report April- (1986) Slash pine growth and . June 1993: 24-38. . Ozores-Hampton, M., T.A. i yield responses to sludge . Obreza, G. Hochmuth. (1998a) : applications. South. J. Appl. For. 10: Obreza, T. A. and R. K. Reeder Using composted wastes on i 142-145. (1994) Municipal solid waste Florida vegetable crops. compost use in tomato/ . Hort Technology 8(2)130-137. i. Rodriguez-Kabana, R. (1986) watermelon successional . Organic and inorganic nitrogen cropping. Soil Crop Sci. Soc. Fla. . Ozores-Hampton, M., T.A. i amendments to soil as nematode . Proc. 53:13-19. . Obreza, and P. J. Stoffella. (1998b) : suppressants. J. Nematol. . Immature compost used for bio- i 18:129-135. . Oliver, Jr., W.M. (1994) The . logical weed control. Citrus and ; . Aspergillus fumigatus problem. . Vegetable Magazine March, 12-14. i Rodriguez-Kabana, R. (199 1) Compost Science and Utilization . Control biologico de nematodos . 2( 1):27-3 1. . Pagliai, M., G. Guidi, M. parasitos de plantas. Nematropica . . LaMarca, M. Giachetti, and G. i 21:111-122. Ostmeyer, T. (1993) A sampling . Laccamante (1981) Effect of i of today’s cornposting alterna- sewage sludges and composts on / Roe, N.E., S.R. Kostewicz. (1992) . tives. Golf Course Management . soil porosity and aggregation. : Germination and early growth of . 6 1 (February): 76-8 1. . J. Environ. Qual. 10(4):556-561. : vegetable seeds in compost. In: C.S. Vavrina, ed., Proc. Natl. Ozores-Hampton, M. and H.H. Parr, J.F., R.I. Papendick and D. i Symp. Stand. Estab. Hort. Crops, pp. Bryan. (1993a) Effect of amend- Colacicco (1986) Recycling of : 191-201. . ing soil with municipal solid . organic waste for a sustainable : waste (MSW) compost on yield . agriculture. Biological Agriculture / Roe, N.E., H.H. Bryan, P.J.
6OCOMPOST USE IN FLORIDA Stoffella, and T.W. Winsberg. .i Shiralipour, A., D.B. McConnell, .i forests. Proceedings 20th Annual (1992) Use of compost as mulch i and W.H. Smith (1992b) Southern Conservation Tillage on bell peppers. Proc. Fla. State. i Compost: Physical and chemical i Conference for Sustainable . Hort. Soc. 105:336-338. . properties of soils as affected by i Agriculture. June 24-26 MSWcompostapplication. Gainesville, Florida, pp 35-39. Roe, N.E., P. J. Stoffella, and H.H. i Biomass and Bioenergy 3(3-4): 195- i Bryan. (1993a) Utilization of i 211. Snyder, G. H., and J. L. Cisar MSW compost and other organic (1996) Effect of compost in turf- mulches on commercial vegetable i Shiralipour, A., and J. Zachary i grass soils on nitrogen release and crops. Compost Sci. Utilization i 1994) Compost Field Experiment ! on leaching of nutrients and . 1(3)73-84. . Guide for California Communities, i organics. Pp. 61-65 In: A Markets prepared for the Santa Barbara : Development Program for Composts Roe, N.E., P. J. Stoffella and H.H. County Solid Waste Management i in Florida, First Annual Report, Bryan. (1993b) Municipal solid Division and the California i April 20, 1996. University of waste compost suppresses weeds Integrated Waste Management .i Florida, Center for Biomass in vegetable crop alleys. Board, 89 pp. Programs, Gainesville. HortScience 28:1171-1172. . Shiralipour, A. (1995) .. Sommers, L.E., and P.M. Rynk, R., M. Van de Kamp, G.B. i Reclamation and revegetation of : Giordano (1984) Use of nitrogen Willson, M.E. Singley, T.L. i diatomite mine spoil by compost i from agricultural, industrial and Richard, J. J. Kolega, F.R. Gouin, : application, Proceedings Composting ! municipal wastes. In: Nitrogen in L. Laliberty, Jr., D. Kay, D.W. / Council’s Sixth Annual Conference: i Crop Production. ASA-CSSA- Murphy, H.A.J. Hoitink and W.F. i Air Quality. Beltsville, MD, i SSSA. 677 South Segoe Road, Brinton (Eds.) (1992) On-farm . October 1995, p. 27. Madison, WI 53711. Composting Handbook. Northeast Regional Agricultural Slivka, D., T. A. McClure, A.R. Stoffella, P. J., Y. Li, D.V. Calvert, Engineering Service, Cooperative Buhr, R. Albrecht (1992) and D.A. Graetz. (1996) Soilless Extension, Ithaca, NY. Compost: United States supply growing media amended with and demand potential. Biomass sugarcane filtercake compost for Sanderson, K.C. (1980) Use of a and Bioenergy 3(3-4):28 l-299. citrus rootstock production. sewage-refuse compost in the :i . Compost Science and Utilization . production of ornamental plants. [ Smith, W.H. (1994a) Recycling 4(2):21-25. . . . HortScience 15: 173-l 78. . composted organic materials in . Florida. Florida Coop. Extn. i Stratton, M.L., A.V.. Barker, and Shiralipour, A. and D.B. . Serv./Inst. Food & Agr. Sci., i J.E. Rechcigl(l995) Compost, pp. McConnell. (1990) Effect of .! Univ. of Florida. BP-2, July 1994. .i 249-309 In: Rechcigl, J.E. (Ed.) compost heat and phytotoxins on : Soil Amendments and Environmental germination of certain Florida .i Smith, W.H. (1994b) Using i Quality, CRC Press, Inc. Boca weed seeds. Soil and Crop Sci. Soc. / compost to recycle Florida’s Raton, FL. of Florida Proceedings 50: 184-157. i. organics in agriculture. In: Proc. of i the Composting Council’s Fifth ! Stratton, M.L. and J.E. Rechcigl Shiralipour, A., D.B. McConnell i Annual Conference. Nov. 16-l 8, / (1997) Compost application to and W.H. Smith. (1991) Effects of i 1994, Washington, DC. Pp. i. ryegrass. Agronomy Abstracts compost heat and phytotoxins on i 44-45. . Sll-031-P. ASA, CSSA, SSSA, germination of certain Florida / October 26-29, 1997, Anaheim, weed seeds. Soil Crop Sci. Soc. i Smith, W.H. (1995) Overview of [ CA. . Florida Proc. 50: 154-157. . research on compost in the USA. ! Proc. of a Conf. on Composting in the / Stratton, M.L. and J.E. Rechcigl Shiralipour, A., D.B. McConnell i Carolinas. Charlotte, NC, January i (1998) Agronomic Benefits of and W.H. Smith (1992a) Uses and i 18-20. Clemson, SC: Clemson .i Agricultural, Municipal, and Benefits of Municipal Solid Waste i Univ., pp. 174-182. Industrial By-products and their Co- Composts: A Literature Review. The i utilization: An Overview. United Cornposting Council, Alexandria, !. Smith, W.H. and A. Shiralipour i States Department of Agriculture, VA.. . (1997) Recycling urban and : Beltsville, MD. . agricultural organics in fields and :
COMPOST USE IN FLORIDA 61 Sun, G., H. Riekerk, and N.B. i Organics Game. American Society i D. J. Mitchell (1996) The effect of Comerford (1995) FLATWOODS i for Horticultural Science Press, .! composted municipal waste as a s.. - A Distributed Hydrologic ; Alexandria, VA. . soil amendment on the growth of . Simulation Model for Florida ! young citrus trees and Pine Flatwoods. Soil Crop Sci. Soc. i United States Department of .i Phytophthora nicotianae. Soil Crop . . Fla. proc. 55:23-32. . Agriculture, Agricultural Sci. Fla. Proc. 55:32-36. . . Research Service (1993) . . Svenson, S.E. (1993) Growth / Agricultural Utilization of . Widmer, T. L., J. H. Graham, and . . Response of West Indies Municipal, Animal and D. J. Mitchell (1997) Potential use . Mahogany to Continuem or i Industrial Wastes. . of composted municipal waste for Osmocote Application during ! management of Phytophthora root Transplanting. University of ’ United States Environmental i rot of bearing citrus. Proc. Fla. Florida, IFAS, Cooperative Protection Agency (1992) i State. Hort. Soc. (in press). Extension Service. Characterization of Municipal Solid i TropicLine 6: l-5. Waste in the United States: I992 i Widmer, T. L., J. H. Graham and Update. Office of Solid Waste and : D. J. Mitchell (1998a) Composted Timmer, L. W., H. A. Sandler, J. Emergency, EPA 530-R-92-019, [ municipal waste reduces infection H. Graham, and S. E. Zitko : Washington DC. of citrus by Phytophthora nico- (1989) Phytophthora feeder root rot :. tianae. Plant Dis. (In press). . of bearing citrus: Fungicide . United States Environmental effects on soil populations of / Protection Agency, Office of Widmer, T. L., J. H. Graham, and Phytophthoraparasitica and citrus .i Solid Waste and Emergency D. J. Mitchell (1998b) Composted Response (1994) Potential end . municipal waste sources and tree productivity. Proc. Fla. State .i . Hort. Soc. 102:5-9. users, pp. 92,95, and Product application methods for growth quality and marketing, p. 102, In: promotion of young citrus trees Timmer, L. W., J. H. Graham, i Composting of Yard Trimmings and infested with Phytophthora and S. E. Zitko. 1998. Metalaxyl- .i Municipal Solid Waste. nicotianae. Biol. Fert. Soils (In resistant isolates of . press). Phytophthora nicotianae: occur- Vavrina, C.S. and W. Summerhill. rence, sensitivity and competitive (1992) Florida vegetable trans- i Wilkinson, J. F. (1994) Applying . parasitic ability on citrus. Plant plant survey, 1989-1990. compost to the golf course. Golf Dis. 82 (In press). Hort Technology 2:480-483. . Course Management . . 62(March):80-88. Tisdale, J.M., and J.M. Oades .i Vavrina, C.S. (1994) Municipal i (1982) Organic matter and water- ! solid waste materials as soilless ! Woolley, J.S., Jr. (1995) The . stable aggregates in soil. J. Soil ’ media for tomato transplant . switch from conventional to Sci. 33: 141. production. Proc. Fla. State Hort. i sustainable. Resource April . Soc. 107:118-120. . 1995:7-9. Turner, M. S., G. A. Clark, C. D. Stanley, and A. G. Smajstrla Watkin, E.M., and J.E. Winch. .i Wootton, R-D., F.R. Gouin and (1994) Physical characteristics of (1974) Composted organic wastes, : EC. Stark (198 1) Composted, . a sandy soil amended with sewage, sludges, and rock . digested sludge as a medium for municipal solid waste compost. phosphate for the amelioration of i growing flowering annuals. J. Soil Crop Sci. Soc. Fla. acid uranium mine-tailings. In: i Amer. Soc. Hort. Sci. 106(1) :46-49. Proc. 53:24-26. Proceedings of the International : . Conference on Land Waste . Zucconi, F., A. Pera, and M. Tyler, R.W. (1993) The promise . Management. J. Tomlinson (Ed.), i Forte. (198 1 a) Evaluating toxicity of compost. American Nurseryman i pp. 48-56. Agricultural Institute of i of immature compost. BioCycle . . 180(14):61-73. . Canada, Ottawa, Ont. 22(2)54-57.
Tyler, R. W. (1994) Fine-tuning i Watson, J.R. (1945) Mulches to i Zucconi, F., M. Forte, A. compost markets. BioCycle August !. control root-knot. Proc. Fla. Acad. i Monaco, and M. de Bertoldi. . 1994:41-48. . Sci. 7:151-153. (198 1 b) Biological evaluation of compost maturity. BioCycle 22(4) Tyler, R.W. (1996) Winning the Widmer, T. L., J. H. Graham, and 26-29.
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