APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING
FUNDAMENTALS OF SUSTAINABLE AGRICULTURE
Sustainable farming meets environmental, economic, and social objectives simultaneously. Environmentally sound agriculture is nature-based rather than factory-based. Economic sustainability depends on profitable enterprises, sound financial planning, proactive marketing, and risk management. Social sustainability results from making decisions with the farm family's and the larger community's quality of life as a value and a goal. This publication discusses the principles of environmental, economic, and social sustainability, and provides practical examples of how to apply them on the farm.
By Preston Sullivan NCAT Agriculture Specialist May 2003 TABLE OF CONTENTS
INTRODUCTION Introduction ...... 1 Environmental Sustainability ...... 2 Economic Sustainability ...... 6 Planning and Decision Making ...... 7 Farming sustainably means growing crops Applying the Principles ...... 8 and livestock in ways that meet three objectives Composts, Manures, and Fertilizers ...... 10 simultaneously: Weed Management ...... 11 Insect Pest Management ...... 12 Plant Disease Management ...... 13 Economic profit Examples of Successful Transitions ...... 13 Summary ...... 15 Social benefits to the farm family and References ...... 15 the community Resources ...... 16
Environmental conservation
Sustainable agricul- ture depends on a whole-system ap- proach whose overall goal is the continuing health of the land and people. Therefore it concentrates on long- term solutions to prob- lems instead of short- term treatment of symptoms.
ATTRA is the national sustainable agriculture information service operated by the National Center for Appropriate Technology, through a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville, AR 72702), Butte, Montana, and Davis, California. Sustainable farming is more than a set of ide- alistic principles or a limited set of practices. ENVIRONMENTAL SUSTAINABILITY Sustainability can be observed and measured; indicators that a farm or rural community is Sustainable agriculture can be viewed as eco- achieving the three objectives of sustainability system management of complex interactions include: among soil, water, plants, animals, climate, and people. The goal is to integrate all these factors into a production system that is appropriate for ECONOMIC SUSTAINABILITY the environment, the people, and the economic The family savings or net worth is con- conditions where the farm is located. sistently going up Farms become and stay environmentally sus- The family debt is consistently going down tainable by imitating natural systems—creating The farm enterprises are consistently a farm landscape that mimics as closely as pos- profitable from year to year sible the complexity of healthy ecosystems. Na- Purchase of off-farm feed and fertilizer is ture tends to function in cycles, so that waste decreasing from one process or system becomes input for Reliance on government payments is de- another. Industrial agriculture, in contrast, tends creasing to function in a linear fashion similar to a fac- tory: inputs go in one end, and products and waste come out the other. The wastes of indus- SOCIAL SUSTAINABILITY trial agriculture (non-point-source pollution) in- The farm supports other businesses and clude suspended soil, nitrates, and phosphates families in the community in stream water, and nitrates and pesticides in Dollars circulate within the local economy ground water. It is a premise of sustainable ag- riculture that a farm is a nature-based system, The number of rural families is going up not a factory. or holding steady The simpler we try to make agriculture, the Young people take over their parents' more vulnerable we become to natural disasters farms and continue farming and marketplace changes. When we try to pro- College graduates return to the commu- duce a single product such as wheat, corn, or nity after graduation soybeans we are taking on huge risk. If instead we diversify crops and integrate plant and ani- ENVIRONMENTAL SUSTAINABILITY mal agriculture, overhead will be spread over There is no bare ground several enterprises, reducing risk and increasing Clean water flows in the farm's ditches and profit. Table 1 offers some comparisons between streams two models of agriculture—farming as an indus- Wildlife is abundant trial factory and farming as a biological system. Fish are prolific in streams that flow TABLE 1 Comparison of the Industrial and through the farm Biological Models of Agriculture Industrial model Biological model The farm landscape is diverse in vegeta- tion ______Energy intensive Information intensive ______Linear process Cyclical process These three objectives are managed more as Farm as factory Farm as ecosystem a single unit, even though we must discuss them ______separately. The three objectives overlap con- ______Enterprise separation Enterprise integration stantly. For example, economic decisions affect ______Single enterprise Many enterprises the local community—buying from out of state ______Monoculture Diversity of plants and animals instead of from a local supplier. Environmental Low-value products Higher-value products decisions affect the economic—allowing soil ero- ______sion increases the need for irrigation and more ______Single-use equipment Multiple-use equipment fertilizer. Each of these objectives is further ex- ______Passive marketing Active marketing amined below.
PAGE 2 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING FARM AS ECOSYSTEM
On any farm, four major ecosystem processes are at work that, if functioning properly, will con- serve the soil and water resources and eventually reduce the overall operating costs. These natural processes—energy flow, water and mineral cycles, and ecosystem dynamics—are observable and manageable. √ Energy flow is the non-cyclical path of solar energy (sunlight) into and through any biological system (Figure 1). The natural world runs on sunlight. Our management decisions affect how much of it is captured and put to good use on the farm (Savory and Butterfield, 1999). Energy flow begins when sunlight is converted into plant growth, and continues when animals consume plants, when predator animals consume prey, and when microorganisms decompose dead plants and animals. Some energy is lost as heat at every transfer point in the food chain. On the farm, energy capture is enhanced by maximizing—both in space and in time—the leaf area available for photosynthesis, and by efficiently cycling the stored solar energy through the food chain. Off-season cover crops, peren- nial vegetation, and intercropping are among the tools for capturing more solar energy. Capturing sunlight and converting it to dollars is the original source of all wealth.
Figure 1. Energy Flow. Source: Sullivan, 1999. Illustration by Janet Bachmann.
√ An effective water cycle is typified by Management of soil organic matter is especially no soil erosion, fast water entry into the soil, and important in row cropping. One recent study the soil's capacity to store large amounts of (Hudson, 1994) showed that raising the water (Figure 2). Streams flow year-round from percentage of organic matter from 1% to 2% in the slow release of water stored in the soil. The sandy soil increased the available water content water cycle is improved by management of that soil by 60% (from 5% of total soil volume decisions that add to or maintain the to 8%). Such an improvement in a soil's groundcover percentage and soil organic matter water-holding capacity will have a beneficial ef- levels—the goal is to get as much water as fect on crop growth, especially during drought possible into the soil during each rainfall. A periods. surface mulch layer speeds water intake while The results of an effective water cycle are low reducing evaporation and protecting the soil surface runoff, low soil surface evaporation, low from erosion. Minimizing or eliminating tillage, drought incidence, low flood incidence, high growing high-residue crops and cover crops, and transpiration by plants, and high seepage of wa- adding compost or manure to the soil maintains ter to underground reservoirs (Savory and groundcover and builds organic matter. Butterfield, 1999).
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 3 Figure 2. Water Cycle. Source: Federal Interagency Stream Restoration Working Group, 2001.
√ A well-functioning mineral cycle—the movement of nutrients from the soil through the crops and animals and back to the soil—means less need for fertilizer and feed from off the farm (Figure 3). In nature, minerals needed for plant and animal growth are continuously recycled within the eco- system with very little waste and no need for added fertilizer. Ultimately, to be sustainable, we need to find ways to use the natural mineral cycle to minimize our off-farm purchase of minerals. Condi- tions and practices that inhibit the natural mineral cycle—erosion, nutrient leaching, organic matter depletion, selling hay or grain off the farm—tend to reduce the farm's sustainability. Practices that enhance the mineral cycle include on-farm feeding of livestock, careful management of manure and crop residues, use of catch crops to reduce nutrient leaching losses, and practices that prevent ero- sion.
PAGE 4 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING Figure 3. Mineral Cycle. Source: Sullivan, 1999. Illustration by Andrea Fournet.
√ An effective ecosystem dynamic is indicated by a high diversity of plants and animals both above and below ground. "Diversity" refers not only to numbers of species, but also to genetic diver- sity within species and to a broad age structure in each population. Greater diversity produces greater stability within the system and minimizes pest problems. Our choices of practices and tools directly affect the level of biodiversity we have on the farm (Table 2). The first step toward increasing biodiversity on the farm is crop rotation, which helps break weed and pest life cycles and provides complementary fertilization among the crops in the planting se- quence. Advancing from rotation to strip intercrops brings a higher level of biodiversity and in- creases sunlight capture. Strip intercropping of corn and soybeans or cotton and alfalfa are two examples. Borders, windbreaks, and special plantings for natural enemies of pests provide habitat for beneficial organisms, further increasing biodiversity and stability. The addition of appropriate perennial crops, shrubs, and trees to the farmscape enhances ecosystem dynamics still further. For more information on practices that increase biodiversity, request the ATTRA publications Agroforestry Overview, Intercropping Principles and Production Practices, and Farmscaping to Enhance Biological Con- trol.
TABLE 2 LISTING OF TOOLS BY THEIR EFFECT ON Increased Biodiversity Intercropping Crop rotation Cover crops Multispecies grazing Decreased Monocropping Tillage Herbicides Insecticides Biodiversity
These four ecosystem processes (energy flow, water cycle, mineral cycle, and ecosystem dynam- ics) function together as a whole, each one complementing the others. When we modify any one of these, we affect the others as well. When we build our farm enterprises around these processes, we are applying nature's principles to sustain the farm for our family and for future generations. When we fight nature's processes, we incur extra costs and create more problems, hurting ourselves and the ecosystem on which we depend.
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 5 ECONOMIC SUSTAINABILITY COMPREHENSIVE FINANCIAL PLANNING IS A MUST
The holistic financial planning process used SELECTING PROFITABLE ENTERPRISES TO ENSURE in Holistic Management™ provides a monthly ECONOMIC SUSTAINABILITY roadmap to help people navigate through their financial year, assured that the profit will be Economic sustainability increasingly de- there at year's end. The income is planned first, pends on selecting profitable enterprises, sound then a planned profit is allocated as the first ex- financial planning, proactive marketing, risk pense item. The remaining expense money is management, and good overall management. allocated sequentially where it will do the most The key for row-crop producers may be to ex- good. This sequential allocation requires that plore income opportunities other than tradi- the farmer spend no more than necessary to run tional commodity crops, such as contract grow- the enterprise for a year, while preserving the ing of seed corn, specialty corn, food-grade soy- planned profit. This potent financial planning beans, or popcorn. These specialty crops are not process empowers people to make decisions that for everyone; only a certain number of acres can are simultaneously good for the environment, be grown because of limited markets. Expand- the local community, and the bottom line. Learn ing organic markets suggest another possible more by requesting the ATTRA publication en- niche. "Alternative" crops like safflower, sun- titled Holistic Management. Also evaluate other flower, flax, and others may be an option for financial planning tools that allow enterprise lengthening a corn and soybean rotation; learn budgeting, cost calculations, partial budgeting more in the ATTRA publication Alternative Ag- analysis, and more—these should be available ronomic Crops. Other examples of diversifica- from your local Extension agent. Business plan- tion strategies are available in the ATTRA pub- ning software is available from local software lications Evaluating a Rural Enterprise and Mov- retail stores. ing Beyond Conventional Cash Cropping. Every farm needs a marketing plan of some Author and successful small farmer Joel type. Marketing can take many forms, ranging Salatin (1998) advocates going with several "cen- from passive marketing in the commodity chain terpiece" enterprises to which can be added sev- to marketing a retail product directly to consum- eral "complementary" enterprises. The comple- ers. Which marketing method you choose will mentary enterprises overlap with the center- have a profound effect on the price your prod- piece enterprises by sharing some of the same uct commands. Doing some market research is overhead requirements, thus lowering overall essential in order to understand your market, costs for all the enterprises. When we try to pro- competition, and consumer trends, and to project duce a single product such as wheat, corn, or potential sales volume and prices. Specialty and soybeans, our risk is high because "all our eggs direct markets such as organic, GMO-free, and are in one basket." When we integrate plant and other "green" markets yield more income but re- animal agriculture we distribute overhead and quire more marketing by the producer. Direct risk among several enterprises. marketing is not for everyone.
SOCIAL SUSTAINABILITY
A profitable farm has a threadbare look Decisions made on the farm have effects in (Salatin, 1998), primarily because money is not the local community. For example, the decision spent on flashy items that don't produce profit. to expand your operation requires the acquisi- Amish farmer David Kline says one of the secrets tion of your neighbor's farm. To have your of staying profitable is "don't spend money" (Myers, neighbor's farm, you must make the decision that 1998). your neighbor's farm is more important to you than your neighbor. Other examples of social decisions include: buying supplies locally rather
PAGE 6 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING than ordering from out of state, figuring out ways to connect local consumers with your farm, tak- sustainability checksheets for beef and dairy en- ing a consumer-oriented approach to production terprises, available by request and on our and management practices where both the website. A more comprehensive approach is farmer and consumer win, and finding opportu- Holistic Management™, mentioned above. Re- nities to ensure that neighboring communities quest the ATTRA publication entitled Holistic can learn about sustainable food production. Management for more information, or contact: Marketing strategies such as community sup- ported agriculture (CSA), direct marketing Allan Savory Center for Holistic through farmers' markets, school tours, and in- Management ternships all have a positive impact on the local 1010 Tijeras, N.W. community. When people have a choice between Albuquerque, NM 87102 supporting local producers or paying a little less 505-842-5252 for the products of the industrial food system, http://www.holisticmanagement.org they will often choose to support their neighbors. Farmers selling locally benefit from differentiat- A successful transition to sustainable farm- ing their products and services by qualities other ing depends on the farmer's careful monitoring than price. Fresh produce, specialty items, and both of progress towards the goal and of the over- locally grown and processed foods are competi- all health of the system. It is useful to assume tive in the market place, especially when con- that your plan will not work and develop a sys- sumer education and personal contact with the tem for determining (as soon as possible) if it isn't farmer are part of the marketing plan. working. For example, if the goal includes in- Social sustainability also includes the qual- creased biodiversity, the farmer needs to know— ity of life of those who work and live on the farm, quickly —if the grazing or cropping system be- including good communication, trust, and mu- ing used is actually increasing the number of tual support. Full family participation in farm plant species per acre. Monitoring is particularly planning is an indication that the quality of life important in sustainable agriculture, which re- is high. Other indicators include talking openly lies on natural systems to replace some of the and honestly, spending time together, a feeling work done by input products like fertilizer and of progress toward goals, and general happiness. pesticides. Quality of life will be defined somewhat differ- The ability to evaluate and replan is vital to ently by each individual and family, based on the farmer who wishes to farm more sustainably. their values and goals. More information on en- When part of the plan is not working as intended, suring that quality of life is accounted for in farm it becomes necessary to replan. The concept of planning is available from the ATTRA publica- planning-monitoring-controlling-replanning is a tion Holistic Management and in books like Rut key characteristic of Holistic Management and Buster: A Visual Goal Setting Book (Burleson and is referred to as the feedback loop. Burleson, 1994). The transition toward more sustainable farm- ing requires not only planning and decision- making skills but access to appropriate and help- PLANNING AND DECISION MAKING ful information. Fortunately, increased interest in sustainable agriculture has stimulated greater investment in research and education. As a re- Managing for three objectives simultaneously sult, much more usable information is available (economics, society, environment) depends on today than ever before, accessible through vari- clear goal-setting and effective decision-making. ous means, one of them being ATTRA. In addi- Several good tools for decision-making, goal-set- tion to publications and custom reports on pro- ting, and whole-farm management are available duction and marketing, ATTRA provides re- to farmers. The Kerr Center for Sustainable Ag- source lists covering sustainable agriculture or- riculture, for example, has developed a ganizations, educational programs, internships, sustainability checksheet with 72 criteria for and related resources. Request an ATTRA Pub- quick evaluation of farming systems (Horne and lications List or go to the ATTRA website for on- McDermott, No date). ATTRA has produced line access to all our publications.
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 7 effect of slight, moderate, and severe erosion on APPLYING THE PRINCIPLES organic matter, soil phosphorus level, and plant- available water on a silt loam soil in Indiana When beginning the transition, the big question is how to apply the principles of Table 3. economic profitability, social enhancement, EFFECT OF EROSION ON ORGANIC MATTER, and ecological improvement in the field, in PHOSPHORUS, AND PLANT-AVAILABLE WATER the community, and in the financial pro- Erosion______level Organic matter Phosphorus Plant-available water cess. The decisions we make on our farms % lbs / ac % and the tools and practices we choose will ______Slight 3 62 7.4 determine the extent to which sustainability ______is realized. The ultimate goal is to farm in Moderate 2.5 61 6.2 ______such a way that we extract our living as the Severe 1.9 40 3.6 interest, while preserving the social, water, ______and soil capital. We want to ensure that our activities do not compromise the landscape Source: Schertz et al., 1984 and community resources over the long term. Now let's look at some management concepts aimed at fostering the four ecosystem (Schertz et al., 1984). processes discussed earlier. When erosion by water and wind occurs at a rate of 7.6 tons/acre/year it costs $40/acre/year to replace the lost nutrients as fertilizer, and around $17/acre/year to pump irrigation water STRIVE TO KEEP THE SOIL COVERED THROUGHOUT THE YEAR to replace the water holding capacity of that lost soil (Troeh et al., 1991). Soil and water lost from Under natural conditions the soil remains U.S. cropland causes productivity loss of ap- covered with a skin of dead plant material, which proximately $27 billion each year (Pimentel et moderates temperature extremes, increases wa- al., 1995). ter penetration and storage, and enhances soil aeration. Most importantly, the soil skin main- tains soil structure and prevents erosion by soft- AVOID MOLDBOARD PLOWING AT ALL COSTS ening the impact of falling raindrops. Bare ground, on the other hand, is vulnerable to wa- Soil is damaged considerably whenever it is ter and wind erosion, dries out more quickly, and turned over. The moldboard plow brings sub- loses organic matter rapidly. soil to the surface and buries the crop residue The major productivity costs associated with layer so deep it is unable to decay properly. Vir- soil erosion come from the replacement of lost tually no soil residue is left on the surface, ex- nutrients and reduced water holding ability, ac- posing the soil to erosion and impairing the wa- counting for 50 to 75% of productivity loss ter and mineral cycles. Today, millions of acres (Pimentel et al., 1995). Soil removed by erosion are being farmed without any tillage at all (no- typically contains about three times more nutri- till) or in such a way that adequate groundcover ents than the soil left behind and is 1.5 to 5 times remains afterwards (ridge till, zone till, mini- richer in organic matter (Pimentel et al., 1995). mum till). Production systems that reduce or This organic matter loss not only results in re- eliminate tillage in a manner consistent with ef- duced water holding capacity and degraded soil fective weed control foster the four ecosystem aggregation, but also loss of plant nutrients, processes discussed above. Read about an inno- which must then be replaced with fertilizers. Five vative no-till system that uses annual cover crops tons of topsoil (the USDA "tolerance level" for in the “Examples of Successful Transitions” sec- erosion) can easily contain 100 pounds of nitro- tion. For more information, request the two gen, 60 pounds of phosphate, 45 pounds of pot- ATTRA publications Conservation Tillage and ash, 2 pounds of calcium, 10 pounds of magne- Pursuing Conservation Tillage for Organic Crop Pro- sium, and 8 pounds of sulfur. Table 3 shows the duction.
PAGE 8 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING greatly reducing the amount of soil exposed to DIVERSIFY degradation. In addition, they receive little or no cultivation after planting, which reduces or- Enterprise diversification reduces financial ganic-matter loss even more. As a result, cereals risk by spreading income and costs (e.g., of pest and green manures can be considered neutral control and fertilizer) out over several crops or crops, replacing soil organic matter at roughly livestock operations. Sustainability is increased the same rate at which it breaks down. Crops when animal wastes become inputs to crop pro- that make a perennial sod cover—such as grasses, duction on the same farm. clovers, and alfalfa—not only keep the soil en- tirely covered, but also have massive root sys- ROTATE CROPS tems, producing far more organic matter than is lost. Sod crops are the best soil-building crops— they can heal the damage done to soil by row Moving from simple monoculture to a higher cropping. level of diversity begins with crop rotations, Incorporating sod crops as a fundamental which break weed and pest life cycles, provide part of a crop rotation not only builds soil but complementary fertilization to crops in sequence supports weed-control strategies as well. Weed with each other—nitrogen-fixing legume crops control improves because the types of weeds en- preceding grain crops such as corn—and prevent couraged by row-cropping systems are usually buildup of pest insects and weeds. In many cases, not adapted to growing in a sod/hay crop. An yield increases follow from the "rotation effect." ideal rotation might include one year of sod crop Including forage crops in the rotation will reduce for each year of row crop, and as many years of soil erosion and increase soil quality. "neutral" crops as makes sense in the circum- stances. Intercropping is the growing of The challenge of incorporating sod crops into two or more crops in proximity a rotation is to include livestock in the system or to find a market for the hay. Sustainable pro- to promote interaction between duction is much easier when livestock are present them. Read the ATTRA publica- in the system to recycle wastes and assist in trans- tions Intercropping Principles ferring (via manure) nutrients from one part of and Production Practices and the farm to another. Fortunately, land capable of producing a 100-bushel corn yield will generally Companion Planting for more be able to produce 5-ton hay yields. With prices information. of $60–$70 per ton being common for ordinary hay, gross revenues per acre from hay will ex- ceed those from corn so long as corn is under When planning crop rotations, it is important $3.00 per bushel. The net- income picture is even to consider that cultivated row crops—such as more encouraging, however, because conven- corn and soybeans or vegetables— tend to be soil- tional production costs for an acre of corn are degrading. Since the soil is open and cultivated quite a bit higher than for hay. A good crop of between rows, microbes break down organic alfalfa fixes at least $50 worth of nitrogen every matter at a more rapid pace. Furthermore, row year, thus reducing fertilizer costs for the subse- crops have modest root systems and conse- quent corn crop. quently do not contribute enough new organic Besides equipment costs, the major drawback matter to replace that lost from the open soil be- to selling hay is that the nutrients it contains are tween rows; in most cases above-ground crop shipped off the farm. Since, however, something residues make only minor contributions to replac- like 75–90% of the minerals going into the front ing lost organic matter. end of cattle come out the back end, keeping Cereals and other crops (including annual cattle helps retain nutrients on the farm. Cattle green manures) planted with a grain drill or can serve as a very profitable method of adding broadcast-seeded are more closely spaced and value to the forage crops they consume. ATTRA have more extensive root systems than row crops, offers an extensive series of publications on sus- tainable beef production and "grass farming."
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 9 Grazing animals and other livestock can be man- Compost has a unique advantage in comparison aged on croplands to reduce costs, increase income, and to unaged manure and other organic soil amend- increase diversity. There are ways of incorporating ani- ments in that it has a (usually) predictable, and mals into cropping without the farmer getting into animal nearly ideal, ratio of carbon to nitrogen (Parnes, husbandry or ownership directly. Collaboration with 1990). Compost can be safely applied at rates of neighbors who own animals will benefit both croppers and livestock owners. Grazing or hogging-off of corn 10 tons per acre (Parnes, 1990) where quantities residue is one example where a cost can be turned into are available. Much higher rates are not unusual, a profit. The animals replace the $6 per-acre stalk mow- especially where soil is being improved rather ing cost and produce income in animal gains. than maintained. Compost has some particular advantages in row crop production, especially when used in USE COVER CROPS AND GREEN MANURES conjunction with cover crops and green manures. In sandy soils, compost's stable organic matter is especially effective at absorbing and retaining Perennial and biennial sod crops, annual water. Fresh plant material incorporated as green green manures, and annual cover crops are im- manure, on the other hand, retains its waxy leaf portant for building soil in field-cropping sys- coating and cannot perform the same function tems. Hairy vetch, for example, not only is a soil- until thoroughly digested by microbes. conserving cover crop, but is capable of provid- There are several conventional fertilizers that ing all the nitrogen required by subsequent crops should be avoided in sustainable farming be- like tomatoes (Abdul-Baki and Teasdale, 1994). cause of their harmful effects on soil organisms The soil-building crops most appropriate for and structure. These include anhydrous ammo- a given farm depend not only on regional fac- nia and potassium chloride. The use of dolo- tors (harshness of winter, etc.) but also on the mite—a liming material having a high magne- type of production system involved: each farmer sium-to-calcium ratio—has also been generally will have to determine which cover crops are discouraged, but most problems result from the most appropriate to his or her system. For more frequent misuse of dolomite for raising pH on information see the ATTRA publication Overview soils already high in magnesium, not from any of Cover Crops and Green Manures. innate detrimental qualities. It is certainly ap- propriate for use on fields deficient in magne- sium, as indicated by a proper soil test. COMPOSTS, MANURES, AND Some of the more "environmentally friendly" FERTILIZERS chemical fertilizers such as mono-ammonium phosphate (12-50-0), commonly called MAP, may also have a role in the transition away from the Crop rotations, cover-cropping, and green- harsher chemical fertilizers. A very serviceable manuring are key strategies for soil building, and affordable 4-16-16 transitional fertilizer with which is the foundation of sustainable farming. magnesium, sulfur, and other minor nutrients However, modern production systems place can be prepared from a combination of two- high demands on land resources, requiring ad- thirds sulfate of potash-magnesia and one-third ditional attention to soil fertility management. mono-ammonium phosphate. When used in ATTRA's Sustainable Soil Management publication combination with composts and/or legume provides practical information about alternative plowdowns (for nitrogen), this 4-16-16 can be soil management approaches. Since some of banded at seeding or otherwise applied just like these approaches entail the use of off-farm in- the regular 5-20-20, but with reduced negative puts, two additional ATTRA publications, Alter- impact on soil life. native Soil Amendments and Sources of Organic Fer- Significant additions of lime, rock phosphate, tilizers & Amendments, are also recommended. and other fertilizers should be guided by soil test- Manures and composts, especially those pro- ing to avoid soil imbalances and unnecessary ex- duced on-farm or available locally at low cost, penditure on inputs. Cooperative Extension of- are ideal resources for cycling nutrients on-farm. fers low-cost soil testing services in many states. From the standpoint of overall soil and crop Also refer to ATTRA's Alternative Soil Testing health, composts or aged manures are preferred. Laboratories publication.
PAGE 10 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING WEED MANAGEMENT Weed Levels at two Nebraska Locations 600 Sidney Weed management poses one of the greatest 500 North Platte challenges to the crafting of sustainable produc- 400 tion systems. However, weed populations tend 300 to decline in severity as soil health builds. A ba- 200 100 sic understanding of weed ecology and the in- Weed numbers/acre 0 fluence of cropping patterns on weed communi- 0 0.75 1.5 2.25 3 ties will help growers refine their use of cultural Mulch rate - tons/acre and mechanical techniques, thereby reducing the Figure 4. Effect of straw mulch on weeds at two time required for effective weed control. locations in Nebraska. Source: Crutchfield et al., Prevention of weed problems is a fundamen- 1985. tal component of man- Table 4. agement. In general Tillage and Cover Crop Mulch Effect on terms, weed prevention Weed Numbers and Production in crops is based on de- veloping a sound rota- Weed weight Tillage Cover crop Weeds/foot2 pounds/foot2 tion, thwarting all at- ______Conventional None 12 0.22 tempts by existing ______weeds to set seed, and ______None None 5 0.14 minimizing the arrival ______None Rye 0.9 0.1 of new weed seeds from ______None Wheat 0.3 0.07 outside the field. In a None Barley 0.8 0.09 grazing system, weed Source: Schertz et al., 1984 management may be as simple as adding other animal species such as goats or sheep to a cattle herd to convert weeds into cash. When rye is killed in place and left undisturbed Certain crops can be used to smother weeds. on the soil surface, these chemicals leach out and Short-duration plantings of buckwheat and sor- prevent germination of small-seeded weeds. ghum-sudangrass, for example, smother weeds Weed suppression is effective for about 30–60 by growing faster and out-competing them. In days (Daar, 1986). If the rye is tilled into the soil, northern states, oats are commonly planted as a the effect is lost. "nurse crop" for alfalfa, clover, and legume-grass Table 4 shows the effects of several cereal mixtures—the oats simply take the place of cover crops on weed production. Note that till- weeds that would otherwise grow between the age alone, in the absence of any cover crop, more young alfalfa plants. than doubled the number of weeds. With enough mulch, weed numbers can be While a good weed-prevention program will greatly reduced. Nebraska scientists applied decrease weed pressure substantially, success- wheat straw in early spring to a field where wheat ful crop production still requires a well-con- had been harvested the previous August. At the ceived program for controlling weeds to the point higher straw rates, weed levels were reduced where they have no negative impact on net in- more than three times over (see Figure 3). Wheat, come. Weed control programs include a range like rye, is also known to possess weed-suppress- of carefully timed interventions designed to kill ing chemicals in the straw itself. This quality is as many young seedlings as possible. ATTRA known as allelopathy. has additional information on weed control op- Rye is one of the most useful allelopathic tions for both agronomic and horticultural crops, cover crops because it is winter-hardy and can available on request, including the publication be grown almost anywhere. Rye residue contains Principles of Sustainable Weed Management for Crop- generous amounts of allelopathic chemicals. lands.
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 11 mulched soil (Ecological Agriculture Projects, No INSECT PEST MANAGEMENT date). Some intercrops thus disguise the host plant from these pests by completely covering Insect pests can have a serious impact on the soil. Other insects recognize their host plant farm income. In ecologically balanced farm pro- by smell; onions planted with carrots mask the duction systems, insect pests are always present, smell of carrots from carrot flies. For more infor- but massive outbreaks resulting in severe eco- mation on companion planting for insect man- nomic damage are minimized. This results in agement see the ATTRA publications good part from the presence of natural control Farmscaping to Enhance Biological Control and Com- agents—especially predatory and parasitic in- panion Planting. sects, mites, and spiders—that keep pest popu- Sooner or later, nearly every grower con- lations in check. To restore populations of fronts unacceptable pest pressure, making some beneficials on the farm, cease or reduce pesticide kind of intervention necessary. Integrated pest use and other practices that harm them, and es- management (IPM) is the basic framework used tablish habitats through farmscaping. to decide when and how pests are controlled. The primary goal of IPM is to give growers man- agement guidelines in order to make pest con- "Farmscaping" refers to practices that trol as economically and ecologically sound as increase diversity on the farm by pro- possible. viding habitat for beneficial organisms. Borders, windbreaks, and special A working knowledge of the life cycles of plantings for natural enemies of pests pests and their natural enemies enables the serve this purpose. Request the grower to identify and exploit the weak link in a ATTRA publication Farmscaping to pest's life cycle. Several good books and publi- Enhance Biological Control for more cations on insect identification are available information. through Cooperative Extension; more can be found in libraries and bookstores.
In diverse farm systems, severe pest out- IPM integrates habitat modification and cul- breaks are rare because natural controls exist to tural, physical, biological, and chemical practices automatically bring populations back into bal- to minimize crop losses. Monitoring, record ance. There is overwhelming evidence that plant keeping, and life-cycle information about pests mixtures (intercrops) support lower numbers of and their natural enemies are used to determine pests than pure stands (Altieri and Liebman, which control measures are needed to keep pests 1994). There are two schools of thought on why below an economically damaging threshold. For this occurs. One suggests that higher natural- more detailied information on IPM, see the enemy populations persist in diverse mixtures ATTRA publication Biointensive Integrated Pest because they provide more continuous food Management. sources (nectar, pollen, and prey) and habitat. Biological control—the use of living organ- The other thought is that pest insects who feed isms to control crop pests— is one of the pillars on only one type of plant have greater opportu- of IPM. Biocontrol agents may be predatory, nity to feed, move around, and breed in pure crop parasitic, or pathogenic; they may also be either stands because their resources are more concen- "natural" (from naturally occurring organisms trated than they would be in a crop mixture such as wild beneficial insects) or "applied" (Altieri and Liebman, 1994). (meaning the organisms are introduced). Intercropping also aids pest control efforts Biocontrol agents include insects, mites, bacte- by reducing the ability of the pest insects to rec- ria, fungi, viruses, and nematodes. Certain ben- ognize their host plants. For example, thrips and eficial nematodes (Steinernema species, for ex- white flies are attracted to green plants with a ample) transmit pathogens to their prey and brown (soil) background, and ignore areas where could be seen as a form of indirectly applied vegetative cover is complete—including biocontrol.
PAGE 12 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING When all other IPM tactics are unable to b)The cultural management phase, based maintain insect pest populations below economic on a thorough understanding of the pest's thresholds, insecticide application to control the biology and its relationship to the crop- pests and prevent economic loss is clearly justi- ping system. Tactics employed to con- fied. In such cases, farmers concerned with trol pests include delayed planting dates, sustainability will usually attempt to obtain sat- crop rotation, altered harvest dates, etc. isfactory control using one of the "biorational" c)The biological control phase, or "bio-in- pesticides, which are fairly pest-specific and usu- tensive IPM," requires thorough under- ally non-persistent, causing a minimal amount standing of the biology of natural en- of harm to beneficial organisms. Biorational pes- emies (in addition to that of the pest) and ticides include some conventional synthetic pest an ability to measure how effective these control materials, but more typically are micro- agents are in controlling pests. When bial insecticides like Bacillus thuringiensis or natural agents do not meet expected Beauveria bassiana; insecticidal soaps; pheromones goals, the IPM practitioner uses "soft" pes- (for trapping or mating disruption), and insect ticides (relatively non-toxic to nontarget growth regulators. Botanical plant extracts like organisms), and times applications for neem and ryania are also known as least-toxic, minimal impact on beneficials. narrow-spectrum controls, combining minimal negative impact on beneficial species with very PLANT DISEASE MANAGEMENT rapid decomposition in the environment. Farms exploring IPM concepts for the first time may limit their involvement to monitoring The first step toward preventing serious dis- levels of one or two pests on a secondary crop, ease problems in any cropping system is the pro- applying their usual insecticide if the threshold duction of healthy plants nurtured by a of economic injury is approached. Others may microbially active soil. Healthy soil suppresses shift from a broad-spectrum insecticide to a more root diseases naturally; the primary means to beneficial-friendly material. As operator com- create disease-suppressive soil is to add biologi- fort with IPM increases, it is common to apply cally active compost at appropriate rates to a soil basic concepts to the primary crop and expand with balanced mineral levels. Supplemental IPM management on the secondary crop—per- strategies include crop rotation, resistant culti- haps through the introduction of beneficial para- vars, good soil drainage, adequate air movement, sites or predators of the target pest insect. and planting clean seed. Biorational fungicides include compost teas (which add beneficial fungi capable of prevent- Farmers need to consider carefully how to ing colonization of the crop by pathogens), bak- manage the shift to fewer pesticides during ing soda, and plant extracts. As with insect pest the first few years, before beneficial insect control, integrated management principles populations have rebuilt to levels where they should be applied, including monitoring of en- can exert significant control of the major vironmental conditions to determine whether pests. Farmers should plan to work closely preventive fungicidal sprays are required. For with local experts—especially farmers with more information on how healthy soil fosters a transition experience—to ensure as smooth drastic reduction in root diseases, request the ATTRA publication Sustainable Management of a shift as possible. Soil-borne Plant Diseases.
As they move towards greater sustainability, IPM programs tend to go through three phases, EXAMPLES OF SUCCESSFUL with each stage using and building on previous TRANSITIONS knowledge and techniques (Ferro, 1993): a)The pesticide management phase, char- STEVE GROFF OF PENNSYLVANIA acterized by establishing economic thresholds, sampling, and spraying as Steve Groff and his family produce veg- needed. etables, alfalfa, and grain crops profitably on 175
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 13 acres in Lancaster County, Pennsylvania. vator will handle 300 to 400 acres very easy , but When Steve took over operation of the family not thousands of acres…. Harvesting ear corn farm 15 years ago, his number-one concern was puts another restraint on farm size. Picking 100 eliminating soil erosion (improving the water acres in the ear is enough. Mowing and baling cycle). Consequently, he began using cover crops 40 acres of hay three or four times during the extensively (improving the water and mineral summer is enough. Looking after 75 beef cows cycle and increasing community dynamics). during calving is enough. There is no desire to Steve uses a 10-foot Buffalo rolling stalk have 150 cows. Including the cow in the farm chopper to transform a green cover crop into a operation keeps the farm and communities in no-till mulch. Under the hitch-mounted frame, balance. When the cow leaves the farm, the oats the stalk chopper has two sets of rollers running and hay crops leave also. The remainder is row in tandem. These rollers can be adjusted for light crop corn and soybeans without manure for fer- or aggressive action and set for continuous cov- tility which calls for purchased fertilizer and her- erage. Steve says the machine can be run up to 8 bicides to control the weeds. As a result, farms miles an hour and does a good job of killing the can get larger and the rural communities decline. cover crop and pushing it right down on the soil. Cleaning pens every two weeks for a 75-sow far- It can also be used to flatten down other crop row to finish hog operation is enough. This 300- residues after harvest. Groff improved his chop- acre farm with livestock is enough and there is per by adding independent linkages and springs no desire to farm the neighbor's land. The higher to each roller. This modification makes each unit labor charges stay in the farmer's pocket making more flexible, to allow continuous use over un- smaller farms profitable, and therefore results in even terrain. Following his chopper, Groff trans- more farm families. More farm families mean plants vegetable seedlings or plants no-till sweet expansion of schools, churches, services and corn and snap beans into the killed mulch. Un- communities. “ (Thompson, 1997) der the cover-crop mulch system, his soils are protected from erosion and have become much THE MOORE FAMILY OF TEXAS mellower (as a result of the improved water cycle). For more information, order Steve's video listed in the Resources section below or visit his For several generations the Moore family Web page, < http://www.cedarmeadowfarm. raised corn, milo, and cotton (Leake, 2001). Hav- com/about.html>, where you can see photos of ing had enough of rising production costs, per- the cover-crop roller and no-till transplanter in sistent drought, and low commodity prices, they action, as well as test-plot results comparing flail decided to break the family tradition and switch mowing, rolling, and herbicide killing of cover from row crops to cattle. After receiving train- crops. ing in Holistic Management™, Robert Moore and his son Taylor designed a system that gives them less personal stress and lower overhead costs. DICK AND SHARON THOMPSON OF IOWA For years they battled Johnson grass, bermuda grass, and crab grass in their cotton fields. Now Dick and Sharon are well known in the sus- these grasses and others such as Dallis grass and tainable agriculture community for an integrated bluestem are their allies. Moore says they are family farm system that has broad implications working with nature by letting the plants that for the larger agricultural community. Their sys- want to be there return. Their cattle love the tem is based not on expansion but on mainte- grasses and the wide variety allows them to graze nance of local community values. Excerpts from from mid-February to mid-November. After giv- a Wallace Institute report describe the social ing up cropping, they increased their cow herd sustainability of their farming operation. In Dick from 200 animals to 600. Their 2000 acres are Thompson's own words: divided into 50-acre paddocks, with about 200 “The size of a farm will be restricted when head in each paddock at various times. With the major part of weed control depends on the their cropping enterprise they had 20 employees rotary hoe and the cultivator. Two cultivations working full time; now the father and son work of the 150 acres of row crops with a four-row together with one full-time employee. Before cultivator are enough along with hay making cattle, they worried about crop success and prices and caring for the livestock. An eight-row culti- and were often relieved just to break even. Now
PAGE 14 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING they can live off what they make. Taylor says, Annual Meeting, Oregon State University, "We're definitely happier now and have less Corvallis. stress." ATTRA has more than a dozen farmer- Altieri, M.A. and M. Liebman. 1994. Insect, ready publications that provide details about weed, and plant disease management in grass farming enterprises and alternative mar- multiple cropping systems. In: C.A. keting of animal products. Francis (ed.) Multiple Cropping Systems. Macmillan Company, New York. 383 p. SUMMARY Anon. 1990. Strip intercropping offers low- input way to boost yields. Sensible Agriculture. May. p. 7-8. Sustainable farming meets economic, envi- ronmental, and social objectives simultaneously; Burleson, Wayne and Connie Burleson. 1994. because these three objectives always overlap, Rut Buster: A Visual Goal Setting Book. they are managed together. Economic Sloping Acre Publishing Company. sustainability requires selecting profitable enter- Absarokee, Montana. 45 p. prises and doing comprehensive financial plan- Crutchfield, Donald A., Gail A. Wicks, and ning. Social sustainability involves keeping Orvin C. Burnside. 1986. Effect of winter money circulating in the local economy, and wheat (Triticum aestivum) straw mulch maintaining or enhancing the quality of life of level on weed control. Weed Science. the farm family. Environmental sustainability Vol. 34, No. 1. p. 110-114. involves keeping the four ecosystem processes (effective energy flow, water and mineral cycles, Daar, Sheila. 1986. Update: Suppressing and viable ecosystem dynamics) in good condi- weeds with allelopathic mulches. The tion. Managing economics, society, and environ- IPM Practitioner. April. p. 1-4. ment simultaneously depends on clear goal-set- Ecological Agriculture Projects. No date. ting, effective decision making, and monitoring Mixing Crop Species. McGill University, to stay on track toward the goal. Wise decisions Macdonald Campus.
//APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING PAGE 15 Amish farms to thrive in today's economy. The herbicides. Vegetables are planted right into this Stockman Grass Farmer. June. p. 1-4. mulch using a no-till transplanter. The Groffs grow high-quality tomatoes, pumpkins, broccoli, snap beans, Parnes, Robert. 1990. Fertile Soil. agAccess, and sweet corn. After several years of no-till produc- Davis, California. p. 51-58. tion their soils are very mellow and easy to plant into. Pimentel, D., C. Harvey, P. Resosudarmo, et al. The video also includes comments from leading re- 1995. Environmental and economic costs searchers working with no-till vegetables. of soil erosion and conservation benefits. Science. Vol. 267, No. 5201. p. 1117-1123. Order for $21.95 + $3.00 shipping from: Putnam, Alan R., Joseph DeFrank and Jane P. Cedar Meadow Farm Barnes. 1983. Exploitation of allelopathy 679 Hilldale Road for weed control in annual and perennial Holtwood, PA 17532 cropping systems. Journal of Chemical 717-284-5152 Ecology. Vol. 9, No. 8. p. 1001-1010. Salatin, Joel. 1998. You Can Farm. Polyface, Inc., Swoope, Virginia. 480 p. Rutbuster: A Visual Goal Setting Book Savory, Allan, with Jody Butterfield. 1999. Wayne and Connie Burlson Holistic Management. Island Press. RR 1, Box 2780 Washington, D.C. 616 p. Absarokee, MT 59001 406-328-6808 Schertz, D.L., W.C. Moldenhaver, D.P. Franzmeier, et al. 1984. Field evaluation of the effect of soil erosion on crop pro- ductivity. p. 9-17. In: Erosion and Soil Productivity. Proceedings of the National Symposium on Erosion and Soil Produc- By Preston Sullivan tivity. American Society of Agricultural NCAT Agriculture Specialist Engineers. December 10-11, 1984. New Orleans, Louisiana. ASAE Publication 8- Edited by Richard Earles 85. Formatted by Ashley Hill Sullivan, P.G. 1999. Early Warning Monitoring for Croplands. Savory Center for Holistic March 2003 Management. 22 p. Thompson, Dick. 1997. Alternatives in Agricul- ture: 1996 Report. Thompson On-Farm Research and the Wallace Institute. p. 3-4. The electronic version of Applying the Troeh, F.R., J.A. Hobbs, R.L. Donahue et al. Principles of Sustainable Farming is 1991. Soil and Water Conservation. located at: Prentice- Hall, Englewood Cliffs, NJ. HTML http://www.attra.ncat.org/attra-pub/trans.html PDF http://www.attra.ncat.org/attra-pub/PDF/ RESOURCES Transition.pdf
No-till Vegetables by Steve Groff. 1997. IP 107 This video leads you through selection of the proper cover-crop mix to plant crops into and shows you how to take out the cover crops with little or no herbicide. You will see Groff's mechanical cover-crop- kill method, which creates ideal no-till mulch without
PAGE 16 //APPLYING THE PRINCIPLES OF SUSTAINABLE FARMING