IRRIGATION TECHNOLOGY DECISIONS: MICROIRRIGATION

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1 IRRIGATION TECHNOLOGY DECISIONS: MICROIRRIGATION Dana O. Porter, PhD, PE Research and Extension Agricultural Engineer Texas A&M AgriLife Research and Extension Center Lubbock Department of Biological and Agricultural Engineering

2 Efficient, advanced irrigation technologies in the Texas High Plains: Water capacity is a limiting factor throughout most of the region Agricultural producers are progressive, relatively rapid adopters of technology critical mass of peer producers and success stories The technologies are good fits for farm operations (fields, crops, managers) in the Texas High Plains Excellent applied research programs in the area (Texas A&M Halfway, Bushland, Amarillo and Etter; USDA ARS Bushland) Critical mass of well qualified and experienced irrigation dealers, designers, installers ready access to technical expertise and support USDA NRCS EQIP cost share and low interest loan options help offset high capital costs Good collaboration among research, extension, industry, producers

3 Efficient advanced irrigation technologies: Important considerations - suitability or adaptability of a technology to local production systems and conditions - economic feasibility - availability of irrigation industry, research and educational infrastructure and resources to support applications in the field Successful application of irrigation technologies requires good design, installation, maintenance, and management.

4 Irrigation in Context: Integrated Production Systems Goals: Crop yield, quality Production efficiency Water, Nitrogen, and Energy Efficiency Efficiency and efficacy of all inputs Manage the overall system for high return Optimal response to inputs Understanding limiting factors Reducing losses and unnecessary inputs Nutrient management Variety selection Integrated Pest Management (IPM) Water management (irrigation, rainfall, soil moisture)

5 MICROIRRIGATION Subsurface drip irrigation Surface drip irrigation Shallow subsurface drip irrigation Microspray irrigation

6 Microspray Irriga on University of California Agriculture and Natural Resources University of California Agriculture and Natural Resources Photo: USDA NRCS

7 Microspray (microtube) Irriga on

8 Surface drip irriga on Microirrigation on trellises in a vineyard

9 Shallow subsurface drip irriga on SSDI

10 Shallow subsurface drip irriga on

11 Photo courtesy: Jim Bordovsky Subsurface Drip Irriga on SDI

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13 Filtra on Hydrocyclone Sand Separator Disc filter Media filters

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16 Soil Moisture Uptake by Plant Roots Plants will get most of their water from the upper part of the root zone. As the shallow water is depleted, the plant will extract water from deeper in the profile if it has roots there, and if water is available.

17 Limits to the Root Zone Depth If roots encounter a confining condition in the soil profile, the effective root zone is limited. Examples of confining conditions: compaction zone, caliche layer, dry layer, saturated layer, salt accumulation

18 Subsurface Drip Irrigation Root Zone Wetted area affects size of root zone every row Potential salt & toxic element accumulation zone alternate furrows

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20 Subsurface Drip Irriga on: Tape Placement & Spacing every row alternate furrows Other configura ons:

21 SDI vs. Center Pivot Photo courtesy: Jim Bordovsky

22 Rodent Damaged Drip Tape

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24 SDI peanuts with cotton in the background, Gaines County, Timely rainfall in the spring made a big difference in germination in this sandy soil.

25 Subsurface Drip Irrigation Advantages and Disadvantages Advantages offered by SDI + improved water use efficiency + energy savings + improved nutrient management (spoon feeding) + improved crop yield and/or quality + decreased labor requirements + system may be automated Disadvantages of SDI high initial cost no deep tillage for control of disease and pests some designs offer limited flexibility potential germination problems (esp. in coarse soils) increased management & maintenance requirements potential damage due to rodents and other influences

26 IRRIGATION TECHNOLOGY Keys to successful implementation Design Layout Installation Maintenance Management Advanced irrigation technologies are good tools for good managers. Technology can reduce labor requirements and improve management options, but it does not replace good management.

27 SDI Tips tart with a good design and installation. Be realistic ith well capacities & management capabilities. e diligent in system maintenance iltration, flushing, chemical injection as needed). onitor flow and pressure as indicators of system erformance and as trouble shooting aids. anage irrigation and other crop inputs for optimal sults. SDI is a good tool for a good manager.

28 SDI SYSTEM MAINTENANCE Regular flushing of drip lines is essential. Proper system design facilitates flushing. design must address flush volume / pressure / velocity design should address operator considerations (ease of flushing, access to flush valves, etc.)

29 Chemical Injection Chemical injection is necessary with row crop drip irrigation systems. prevent emitter plugging fertilization of a limited root zone limited IPM applications

30 Chemical Injection revent emitter plugging * requirements depend upon water quality acid injection prevents calcium and magnesium carbonate precipitation; may be effective in controlling slimy bacteria; may be used to control root intrusion; soil ph adjustment may be warranted for other agronomic reasons. chlorine controls growth of algae and slimy bacteria pecial requirements (i.e. H 2 O 2 to prevent Mn precipitation)

31 SDI Water Quality Considerations ecommended water quality tests lectrical Conductivity (EC) measured in ds/m or mmho/cm a measure of total salinity or total dissolved solids H a measure of acidity where 1 is very acidic, 14 is very alkaline, and 7 is neutral ations measured in meq/l, (milliequivalent/liter), includes: Calcium (Ca), Magnesium (Mg), and Sodium (Na) nions measured in meq/l, includes: Chloride (Cl), Sulfate (SO4), Carbonate (CO3), and Bicarbonate (HCO3) nd others. consult recommended references

32 Chemical Injection ertilization, Fertigation spoon feeding to meet crop requirements * fertilizer savings and/or better crop response to applied nitrogen fertilizer * reduced fertilizer costs * reduced leaching losses * address issue of limited root zone and other nutrient access factors

33 Chemical Injection Considerations: Chemical labels EPA requires statements on pesticide labels addressing: type of irrigation system(s) risks associated with non uniform water application calibration backflow protection requirements Backflow prevention required!! Injection (mixing, injection pumps, precipitate jar testing) Compatibility with water quality

34 Note: these values do not take into account irrigation efficiency.

35 USEFUL INFORMATION, TOOLS AND RESOURCES

36 USDA ARS Ogallala Aquifer Program USDA NIFA Microirrigation Research Group

37 h p://

38 Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/#

39 Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/# Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/#

40 Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/# Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/#

41 Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/# Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/#

42 Maintenance of Microirriga on Systems h p://micromaintain.ucanr.edu/#

43 Maintenance of Microirrigation Systems

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46 w.ksre.ksu.edu/mil/

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48 watermgmt.tamu.edu/

49 Texas High Plains ET Network Weather Station, Lubbock, TX

50 Subsurface Drip Irrigation bsurface Drip Irrigation has gained a lot of ground in High Plains particularly in cotton production systems he Texas Southern High Plains. I is highly efficient, with little or no risk of runoff or face evaporation (although as with any irrigation method, excessive ation applications can be lost through deep percolation.) sson from the drought: Good design with adequate ing is critical to flexibility to adjust to declining water acities. nagement and maintenance are key.

51 Subsurface Drip Irrigation Subsurface Drip Irrigation is a good tool for a good manager. It does not solve all problems, and it does not fit every operation. SDI fits well for a wide variety of applications, but shows particular advantage for operations with Limited irrigation capacities Small or irregularly shaped fields Management capabilities to manage and maintain the systems (equipment, chemicals, intensive crop management)

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