DOCSLIB.ORG

Chapter 7 Microirrigation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Chapter 7 Microirrigation Part 623 Irrigation United States Department of Agriculture National Engineering Handbook Natural Resources Conservation Service Chapter 7 Microirrigation (210–VI–NEH, October 2013) Chapter 7 Microirrigation Part 623 National Engineering Handbook Issued October 2013 The U.S. Department of Agriculture (USDA) prohibits discrimination against its customers. If you believe you experienced discrimination when obtaining services from USDA, participating in a USDA program, or partici- pating in a program that receives financial assistance from USDA, you may file a complaint with USDA. Information about how to file a discrimination complaint is available from the Office of the Assistant Secretary for Civil Rights. USDA prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applica- ble, sex (including gender identity and expression), marital status, familial status, parental status, religion, sexual orientation, political beliefs, genetic information, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) To file a complaint of discrimination, complete, sign, and mail a program discrimination complaint form, available at any USDA office location or online at www.ascr.usda.gov, or write to: USDA Office of the Assistant Secretary for Civil Rights 1400 Independence Avenue, SW. Washington, DC 20250–9410 Or call toll free at (866) 632–9992 (voice) to obtain additional information, the appropriate office or to request documents. Individuals who are deaf, hard of hearing, or have speech disabilities may contact USDA through the Federal Relay service at (800) 877–8339 or (800) 845–6136 (in Spanish). USDA is an equal opportunity provider, employer, and lender. Persons with disabilities who require alternative means for communication of program information (e.g., Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720–2600 (voice and TDD). (210–VI–NEH, October 2013) Acknowledgments Chapter 7, Trickle Irrigation, was originally prepared and printed in 1983 under the direction of Conservation Engineering Division (CED), Washington, DC, Soil Conserva- tion Service (SCS), now the Natural Resources Conservation Service (NRCS). In 2003, under the direction of Ron Marlow (retired), Washington, DC, Dr. Claude J. Phene reviewed and updated chapter 7, now called Microirrigation. Final revisions and editing to the chapter were provided by Clarence Prestwich, irrigation engineer, West National Technology Center (WNTSC), NRCS, Portland, OR; Peter Robinson, water management engineer, WNTC, NRCS, Portland, OR; John Busch (retired), State irrigation engineer, NRCS, Baker, OR; Marty Soffran (retired), NRCS, Garden City, KS; Bruce Sandoval, State irrigation engineer, NRCS, Twin Falls, ID; Leigh Nelson, State irrigation engineer, NRCS, Ephrata, WA; Chris Stoner, State irrigation engineer, NRCS, Stillwater, OK; and Cleon Namken, irrigation engineer, NRCS , Lubbock, TX. It was finalized under the guidance ofRob Sampson, national water management engineer, CED, NRCS, Washington, DC. The editing, illustrations, and formatting were provided by Lynn Owens, editor; Wendy Pierce, illustrator; and Suzi Self, editorial assistant, National Geospatial Center of Excellence (NGCE), NRCS, Fort Worth, TX. (210–VI–NEH, October 2013) Chapter 7 Microirrigation Part 623 National Engineering Handbook 7–ii (210–VI–NEH, October 2013) Chapter 7 Microirrigation Contents 623.0700 Introduction 7–1 623.0701 Description 7–1 623.0702 Types of systems 7–2 (a) Drip irrigation ....................................................................................................... 7–2 (b) Subsurface drip irrigation .................................................................................. 7–2 (c) Bubbler .................................................................................................................. 7–3 (d) Jet, mist, and spray systems ................................................................................ 7–3 623.0703 Factors affecting the choice and type of a MI system 7–4 623.0704 Advantages 7–5 (a) Water conservation .............................................................................................. 7–5 (b) Farm operational cost savings ............................................................................ 7–6 (c) Improved crop management ............................................................................... 7–6 (d) Use of recycled and wastewater ........................................................................ 7–7 (e) Use of saline water ............................................................................................... 7–7 (f) Use of MI in nontypical irrigation conditions ................................................... 7–7 (g) Use for frost protection ....................................................................................... 7–8 (h) Potential improved distribution uniformity of water and chemicals ............ 7–8 623.0705 Disadvantages 7–9 (a) Cost ....................................................................................................................... 7–9 (b) Clogging ................................................................................................................ 7–9 (c) Lack and/or decrease of uniformity ................................................................... 7–9 (d) Salt accumulation ................................................................................................ 7–9 (e) Potential root intrusion ..................................................................................... 7–10 (f) Root pinching with SDI in orchards................................................................. 7–10 (g) High level of operation/maintenance ............................................................... 7–10 (h) Rodents and insects .......................................................................................... 7–11 (i) System malfunctions .......................................................................................... 7–11 (j) Germination of field crops ................................................................................ 7–11 (k) Disposal of used polyethylene tapes ................................................................ 7–12 623.0706 Water quality factors and considerations affecting the performance 7–12 of microirrigation systems (a) Physical factors .................................................................................................. 7–12 (b) Chemical factors ................................................................................................. 7–14 (c) Biological factors ............................................................................................... 7–15 (d) Combined factors ............................................................................................... 7–15 (e) Chemical precipitation reactions ..................................................................... 7–15 (f) Chlorination ....................................................................................................... 7–16 (210–VI–NEH, October 2013) 7–iii Chapter 7 Microirrigation Part 623 National Engineering Handbook 623.0707 Fertigation 7–19 (a) Benefits ................................................................................................................ 7–19 (b) Factors affecting fertigation ............................................................................. 7–19 (c) Plant nutrients and fertilizers ........................................................................... 7–20 623.0708 Components of a MI system 7–26 (a) The control head ................................................................................................ 7–29 (b) Appurtances ........................................................................................................ 7–48 (c) Main, submain, and manifolds .......................................................................... 7–55 (d) Laterals and emitters ......................................................................................... 7–57 (d) Flush system ....................................................................................................... 7–64 623.0709 Operations and maintenance 7–65 (a) Operation ............................................................................................................. 7–65 (b) Maintenance ....................................................................................................... 7–65 623.0710 Soil-plant-water relations 7–69 (a) How water movement in the soil works ........................................................ 7–69 (b) Potential of high-frequency irrigation scheduling ......................................... 7–72 (c) Soil wetting patterns ......................................................................................... 7–72 (d) Percent area wetted ........................................................................................... 7–78 (e) Managing irrigation water requirements ........................................................ 7–79 (f) Maximum net depth of water application ...................................................... 7–79 (g) Evapotranspiration rate .................................................................................... 7–79 (h) Seasonal evapotranspiration rate
Load more

Recommended publications
  • Land Use Change, Modelling of Soil Salinity And
    KWAME NKRUMAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, KUMASI, GHANA LAND USE CHANGE, MODELLING OF SOIL SALINITY AND HOUSEHOLDS’ DECISIONS UNDER CLIMATE CHANGE SCENARIOS IN THE COASTAL AGRICULTURAL AREA OF SENEGAL BY Sophie THIAM (BSc. Natural Sciences, MSc. Natural Resources Management and Sustainable Development) A Thesis submitted to the Department of Civil Engineering, College of Engineering in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Climate Change and Land Use June, 2019 DECLARATION I hereby declare that this submission is my own work towards the PhD in Climate Change and Land Use and that, to the best of my knowledge, it contains no material previously published by another person, nor material which has been accepted for the award of any other degree of the University, except where due acknowledgment has been made in the text. Sophie Thiam (PG7281816) Signature…………………Date………………... Certified by: Prof. Nicholas Kyei-Baffour Signature…………….…….Date……………… Department of Agricultural and Biosystems Engineering Kwame Nkrumah University of Science and Technology (Supervisor) Dr. François Matty Signature................................Date………… Institut des Sciences De l’Environnement University Cheikh Anta Diop of Dakar (Supervisor) Dr. Grace B.Villamor Signature………………….Date…………… Centre for Resilience Communities University of Idaho (Supervisor) Prof. Samuel Nii Odai Signature………………..Date………………. Head of Department of Civil Engineering i ABSTRACT Soil salinity remains one of the most severe environmental problems in the coastal agricultural areas in Senegal. It reduces crop yields thereby endangering smallholder farmers’ livelihood. To support effective land management, especially in coastal areas where impacts of climate change have induced soil salinity and food insecurity, this study investigated the patterns and impacts of soil salinity in a coastal agricultural landscape by developing an Agent-Based Model (ABM) for Djilor District, Fatick Region, Senegal.
    [Show full text]
  • Salinity Management and Soil Amendments for Southwestern Pecan Orchards J.L
    ARIZONA COOPERATIVE E TENSION College of Agriculture and Life Sciences AZ1411 Revised 10/11 SALINITY MANAGEMENT AND SOIL AMENDMENTS FOR SOUTHWESTERN PECAN ORCHARDS J.L. Walworth Introduction Managing salts in Southwestern pecan orchards can be a major 1.0 challenge for growers, due to limited soil permeability and/or 1219721972 low-quality irrigation water. However, effective, long-term salt 1319631963 management is essential for maintaining productivity of pecan 0.8 1219721972 orchards. The challenge is to effectively manage soil salinity and sodium (Na) in a cost-effective manner, using appropriate combinations of irrigation management, soil management, and 0.6 soil amendments. Formation of Soil Salinity 0.4 Many arid region soils naturally contain high concentrations of soluble salts, because soil weathering processes dependent 0.2 upon precipitation have not been sufficiently intense to leach RTD = -0.095 x ECe –1.09 salts out of soils. Irrigation water and fertilizers contain salts R = -0.89** that may contribute further to the problem. Poor soil drainage due to the presence of compacted layers (hardpans, plowpans, 0.0 caliche, and clay lenses), heavy clay texture, or sodium problems 0022446688 may prevent downward movement of water and salts, making implementation of soil salinity control measures difficult. ECe (dS/m) Adequate soil drainage, needed to allow leaching of water and salts below the root zone of the trees, is absolutely essential for Figure 1. Reduction in pecan relative trunk diameter with increasing soil effective management of soil salinity. salt concentrations. After Miyamoto, et al., Irrig. Sci. (1986) 7:83-95. The risk of soil salinity formation is always greater in fine- textured (heavy) soils than in coarse-textured soils.
    [Show full text]
  • Pages 406 To
    397 SOIL SALINITY CONTROL UNDER BARLEY CULTIVATION USING A LABORATORY DRY DRAINAGE MODEL Shahab Ansari 1,*, Behrouz Mostafazadeh-Fard 2, Jahangir Abedi Koupai3 Abstract The drainage of agricultural fields is carried out in order to control soil salinity and the water table. Conventional drainage methods such as lateral drainage and interceptor drains have been used for many years. These methods increase agriculture production; but they are expensive and often cause environmental contaminations. One of the inexpensive and more environmental friendly methods that can be used in arid and semi-arid regions to remove excess salts from irrigated lands to non- irrigated or fallow lands is dry drainage. In the dry drainage method, natural soil system and the evaporation of fallow land is used to control soil salinity and the water table of irrigated land. There are few studies about dry drainage concepts. it is also important to study soil salt changes over time because of salt movements from irrigated areas to non-irrigated areas especially under plant cultivation. In this study a laboratory model which is able to simulate dry drainage was used to investigate soil salts transport under barley cultivation. The model was studied during the barley growing season and for a constant water table. During the growing season soil salinities of irrigated and non-irrigated areas were measured at different time. The Results showed that dry drainage can control the soil salinity of an irrigated area. The excess salts leached from an irrigated area and accumulated in the non-irrigated area and the leaching rate changed over time.
    [Show full text]
  • Problems of Salination of Land in Coastal Areas of India and Suitable Protection Measures
    Government of India Ministry of Water Resources, River Development & Ganga Rejuvenation A report on Problems of Salination of Land in Coastal Areas of India and Suitable Protection Measures Hydrological Studies Organization Central Water Commission New Delhi July, 2017 'qffif ~ "1~~ cg'il'( ~ \jf"(>f 3mft1T Narendra Kumar \jf"(>f -«mur~' ;:rcft fctq;m 3tR 1'j1n WefOT q?II cl<l 3re2iM q;a:m ~0 315 ('G),~ '1cA ~ ~ tf~q, 1{ffit tf'(Chl '( 3TR. cfi. ~. ~ ~-110066 Chairman Government of India Central Water Commission & Ex-Officio Secretary to the Govt. of India Ministry of Water Resources, River Development and Ganga Rejuvenation Room No. 315 (S), Sewa Bhawan R. K. Puram, New Delhi-110066 FOREWORD Salinity is a significant challenge and poses risks to sustainable development of Coastal regions of India. If left unmanaged, salinity has serious implications for water quality, biodiversity, agricultural productivity, supply of water for critical human needs and industry and the longevity of infrastructure. The Coastal Salinity has become a persistent problem due to ingress of the sea water inland. This is the most significant environmental and economical challenge and needs immediate attention. The coastal areas are more susceptible as these are pockets of development in the country. Most of the trade happens in the coastal areas which lead to extensive migration in the coastal areas. This led to the depletion of the coastal fresh water resources. Digging more and more deeper wells has led to the ingress of sea water into the fresh water aquifers turning them saline. The rainfall patterns, water resources, geology/hydro-geology vary from region to region along the coastal belt.
    [Show full text]
  • Advanced Nutrients Iguana Juice Bloom 1 Liter 5200-14
    Directions: Use 4 mL per Liter of water. Shake well to take full advantage of this product Organic Iguana Juice Bloom 4-3-6 and put it to work for you. Technical Support: 1-800-640-9605 Now Get Organic Flowers and One-Part Convenience www.advancednutrients.com/tech Iguana Juice Bloom is a one-part, all-organic bloom base that works in all WARNING: DO NOT SWALLOW types of hydroponics systems to provide your plants what they need for bloom KEEP OUT OF REACH OF CHILDREN phase energy production, flower development, and strong metabolism. Use Information regarding the contents and levels of metals in this product is available on the internet at Iguana Juice Bloom when you want the value-enhancing benefits of organic http://www.aapfco.org/metals.htm crops. Company Founders’ NO-RISK, 100% Money Back Iguana Juice Bloom has been specially designed for use with all hydroponics, GUARANTEE sphagnum and soil growing mediums. Iguana Juice Bloom was specifically built for growers just like you, who have very specific Iguana Juice Bloom has been developed for use with any and all hydroponic, demands and expectations from your hydroponics needs. When you use Iguana aeroponic, drip irrigation, NFT, flood & drain, drip emitters and continuous Juice Bloom it must perform flawlessly for liquid feed growing systems. you. You’ll find it will mix easily and quickly 4-3-6 into your reservoir and deliver the goods you’re looking for. GUARANTEED ANALYSIS: What’s more..., Iguana Juice Bloom will work Total Nitrogen (N)............................................................... 4% every time for you using any and all hydroponics, sphagnum and soil growing 4%.................................
    [Show full text]
  • Integrated Irrigation and Aquaculture in West Africa: Concepts, Practices and Potential
    CCOVEROVER [[Converted].aiConverted].ai 33-03-2006-03-2006 12:21:2012:21:20 INTEGRATED IRRIGATION AND AQUACULTURE INWESTAFRICA—Concepts,practicesandpotential ANDAQUACULTURE IRRIGATION INTEGRATED FAO This volume contains background documents and papers presented at the FAO-WARDA Workshop on Integrated Irrigation Aquaculture (IIA) held in Bamako, Mali, from 4 to 7 November 2003, as well as the findings of FAO expert missions on IIA in the West Africa region. The rationale for IIA development lies in its potential to increase productivity of scarce freshwater resources for improved livelihoods and to reduce pressure on natural resources, which is particularly important in the drought-prone countries of West Africa where water scarcity, food security and environmental degradation are priority issues for policy-makers. Irrigated systems, floodplains and inland valley bottoms are identified as C the three main target environments for IIA in West Africa. Many examples M of current practices, constraints and potential for development of IIA are Y provided. The concepts of economic analyses of IIA are reviewed, and an CM overview of regional and international research institutions and networks MY CY and their mandates as they relate to IIA is given. Key factors for successful CMY adoption of IIA – participation of stakeholders and support for local K development, an integrated, multisectoral approach to IIA and improved knowledge management and networking – indicate the way forward and are reflected in a proposal for IIA development in West Africa. INTEGRATED IRRIGATION AND AQUACULTURE IN WEST AFRICA Concepts, practices and potential ISBN 92-5-105491-6 9 7 8 9 2 5 1 0 5 4 9 1 8 TC/M/A0444E/1/3.06/2500 CCover-IIover-II [[Converted].aiConverted].ai 33-03-2006-03-2006 112:22:302:22:30 C M Y CM MY CY CMY K Cover page: FAO photos by A.
    [Show full text]
  • Design & Development of Automatic Soil Salinity Control System
    International Journal of Latest Trends in Engineering and Technology (IJLTET) Design & Development of Automatic Soil Salinity Control System Praveen Kumar Department of Electronics and Communication Engineering MVN University, Palwal, Haryana, India Dr. S. K. Luthra Vice Chancellor MVN University, Palwal, Haryana India Dr. Rajeev Ratan Head of Department of Electronics and Communication Engineering MVN University, Palwal, Haryana India Abstract - The main objective of this project is to control soil salinity and improve soil fertility. The word salinity defines amount of salt present in water or soil which tends to decrease soil fertility through natural or human induced processes that results in the accumulation of dissolved salt in the soil water to an extent that inhibits plant growth and salinity is a severe environmental hazards that degrades the growth of many crops Spatial characterization of soil salinity is required for establishing salt control measurements in irrigated agriculture. For that, cost-effective, specific, rapid, and reliable methodologies for determining soil salinity in-situ and processing those data are required. Keywords: Microcontroller AT89S52, Soil Salinity, Salinity Sensor, salinity control I. INTRODUCTION Salinity means amount of salt in water and soil . soil salinity means unwanted amount of salt present in soil .As population is increasing so demands of food increasing ,soil salinity degrads quality of food availability in market. The accumulated salts include sodium , potassium, magnesium, calcium, chloride, sulphate, carbonate and bicarbonate. primary salinization involves salt accumulation through natural process due to high salt containment in ground water , whereas in secondary salinization is due to human interventions such as inappropriate irrigation procedure e.g with salt rich irrigation water.
    [Show full text]
  • Subsurface Drip Irrigation Why Choose a Netafim Drip Irrigation System?
    SUBSURFACE DRIP IRRIGATION WHY CHOOSE A NETAFIM DRIP IRRIGATION SYSTEM? Pioneered by Netafim in 1965, drip irrigation is an established irrigation technology that delivers water and nutrients directly to the plant root zone, minimizing waste and improving crop performance. For decades, drip irrigation has been used as a proven method for watering high-value vegetable crops, but it wasn’t until the 1990s that drip irrigation expanded to larger scale use in row crops. Since 1995 over 30 billion feet of dripline has been installed into row crop fields in the United States. The success of drip irrigation has been attributed to many factors. The primary reason has been the evolution of equipment developed during the past 20 years - advanced equipment that allows a grower with little or no experience to succeed. WHAT IS DRIP IRRIGATION? Drip irrigation is more than an irrigation method, it is a management tool that allows producers to apply the precise amount of water directly to the root zone, to improve control of fertilizer application, eliminate run-off and evaporation and drive consistently higher yields through improved plant health. With a subsurface drip irrigation (SDI) system, driplines are buried below the soil surface enabling water and nutrients to easily reach each plant’s root zone. WHAT CAN DRIP IRRIGATION DO FOR MY FARM? As a field management tool, drip irrigation gives the grower control over the root zone environment of crops. Growers worldwide are experiencing the numerous benefits of drip irrigation both in the field and
    [Show full text]
  • Creating an Inventory for Vertical Farming Cultivation Techniques Coupled to the Concept of People, Planet and Profit
    Creating an inventory for vertical farming cultivation techniques coupled to the concept of people, planet and profit. Bachelor Thesis Business and Consumer Studies Student: Willem van Spanje Registration number: 940321788120 BSc program: BSC Bedrijfs- en Consumentenwetenschappen Supervisor: Emiel Wubben 2nd Supervisor: Verena Otter Course code: YSS-81812 Period: 3,4,5,6,1 Study load: 12 credits Date: 19-10-2020 1 Abstract This thesis aims to create insight for researchers, investors, and other stakeholders in the vertical farming business. Although a lot of research has been done regarding vertical farms and the cultivation techniques that can be used, a recent comprehensive literature review is missing. The aforementioned insight is created by analyzing the benefits and challenges of three different vertical farm cultivation techniques. These benefits and challenges are analyzed on a checklist with elements of the Triple-Layered Business Model Canvas. This way insight is created in how each vertical farming cultivation technique performs on multiple elements within the economic and environmental dimension of the checklist with elements of the Triple Layered Business Model Canvas. The methodology used in this thesis is a literature review. Papers from peer-reviewed journals are analyzed, used, and put into context. It was found that as of now there is one cultivation technique that performs better than other techniques concerning vertical farming, namely, aeroponics. This thesis also shows that aeroponics is the most promising cultivation technique. Furthermore, this thesis discusses that depending on a stakeholders priorities, their view of what is the optimal cultivation technique can differ from what other stakeholders might consider the optimal cultivation technique.
    [Show full text]
  • Evaluation of Subsurface Drainage Techniques Used for Dryland Salinity
    EVALUATION OF SUBSURFACE DRAINAGE TECHNIQUES USED FOR DRYLAND SALINITY CONTROL A Thesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment ofthe Requirements for the Degree ofMaster ofScience in the Division ofEnvironmental Engineering University ofSaskatchewan Saskatoon By Warren Douglas Helgason Fall 2000 © Copyright Warren Douglas Helgason, 2000. All rights reserved. PERMISSION TO USE In presenting this thesis in partial fulfillment ofthe requirements for a Postgraduate degree from the University ofSaskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree permission for copYing ofthis thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head ofthe Department or the Dean ofthe College in which my thesis work was done. It is understood that any coPYing or publication or use ofthis thesis or parts thereoffor financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which be made ofany material in my thesis. Requests for permission to copy or to make other use ofmaterial in this thesis in whole or in part should be addressed to: Chair ofthe Division ofEnvironmental Engineering University ofSaskatchewan Saskatoon, Saskatchewan, sm 5A9 1 DATA ACKNOWLEDGEMENTS AND RESTRICTIONS All raw data used in this study dated prior to 1997 were collected by the staffat Agriculture and Agri-Food Canada's Semiarid Prairie Agricultural Research Centre (SPARC) in Swift Current, Saskatchewan.
    [Show full text]
  • Drip Irrigation: an Introduction
    SUSTAINABLE AGRICULTURE TECHNIQUES Drip irrigation provides slow, even application of low-pressure water to soil and plants using EM 8782 • Revised March 2013 plastic tubing placed in or near the plants’ root zone. It is an alternative to sprinkler or furrow methods of irrigating crops. Drip irrigation can Drip Irrigation: be used for crops with high or low water demands. An Introduction Why consider drip irrigation? C.C. Shock Drip irrigation can help you use water efficiently. A well-designed drip irrigation system loses practically no water to runoff, evaporation, or deep percolation in silty soils. Drip irrigation reduces water contact with crop leaves, stems, and fruit. Thus, conditions may be less favorable for disease development. Irrigation scheduling can be managed precisely to meet crop demands, holding the promise of increased yield and quality. Growers and irrigation professionals often refer to “subsurface drip irrigation,” or SDI. When a drip tape or tube is buried below the soil surface, it is less vulnerable to damage due to UV radiation, cultivation, or weeding. With SDI, water use efficiency is maximized because there is even less evaporation or runoff. Agricultural chemicals can be applied more efficiently through drip irrigation. Since only the Drip irrigation tubing used to irrigate wine crop root zone is irrigated, nitrogen already in the grapes. soil is less subject to leaching losses, and applied fertilizer can be used more efficiently. In the case of insecticides, less product might be needed. Make sure the insecticide is labeled for application through drip irrigation, and follow the label instructions. Additional advantages of drip irrigation include the following.
    [Show full text]
  • Triggering Drip Irrigation Onset by Soil Water Tension Clinton C. Shock
    Triggering drip irrigation onset by soil water tension Clinton C. Shock, Oregon State University Malheur Experiment Station, Ontario, Oregon [email protected] Feng-Xin Wang, China Agricultural University, Beijing, China, [email protected] Alan D. Campbell, SmartVineyards LLC, Portland, Oregon, [email protected] Hector Dominguez-Aguirre, SmartVineyards LLC, Portland, Oregon, [email protected] Sustainable irrigated agricultural production depends on high and stable productivity using limited inputs of water and nutrients. When irrigation events are triggered by soil water tension (SWT) criteria, the criteria should be adjusted to precisely meet plant needs and provide increments of applied water consistent with soil properties. Drip irrigation systems are often used for triggered irrigation due to the potential to precisely control the irrigation system. Here we review the processes of collecting, filtering, and using SWT data for irrigation onset. A compilation of the successful triggering of irrigation onset using SWT criteria for many crops is discussed. Introduction Precise irrigation is becoming extremely important due to the shortages of water, competition for water, increase in population, consumer preferences for consumption of meat in the developing countries, and environmental pollution resulting from the excessive application of irrigation water. There are several irrigation scheduling techniques that can be used to obtain excellent irrigation scheduling. These include the use of estimates of crop evapotranspiration, SWT, soil water content, or plant stress. In the following paragraphs we will discuss applications of the use of SWT for precise irrigation scheduling. Six years ago two of us (Shock and Wang, 2011) summarized the literature on the use of SWT as an irrigation onset criteria.
    [Show full text]