Water Series: Pt 4 ~ Checklist to Drought-Proof Your Farm

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Photo credit: CAWSI

The checklist below was first presented at the EcoFarm Conference in 2010 by Michael Cahn, irrigation and water resources advisor UC Cooperative Extension, Monterey County, on behalf of the California Agricultural Water Stewardship Initiative (CAWSI). Introductory text excerpted from a California Climate & Agriculture Network blog written by Kendall Lambert, Water Program Coordinator at Community Alliance with Family Farmers (CAFF).

As we are all very much aware, California is now faced with a historic drought. Among other things, this means that farmers and ranchers will have limited access to surface water for irrigation, and many growers will not be able to sufficiently and sustainably substitute groundwater. To better prepare for water shortages like this one, growers can adopt on-farm ‘water stewardship’ practices to optimize agricultural production, achieve economic savings, and boost ecological and human health benefits.

So what can farmers do? Below is a practical checklist presented at EcoFarm in 2010 (it can also be found in our Water & Irrigation Toolkit):

General strategies

  • Fallow least productive fields if water supply is not sufficient for the optimizing production on all fields
  • Optimize soil fertility to maximize production from available water
  • Use reduced/conservation tillage to improve soil structure and to reduce pre-season water needed to facilitate tillage operations

Use winter precipitation and irrigation run-off

  • Capture storm run-off in ponds/reservoirs
  • Plant fall/winter cover crops to minimize storm run-off from fields
  • Vegetate permanent ditches to slow storm run-off and maximize ground water recharge
  • Furrow dike to slow storm run-off from fields
  • Capture irrigation tail water in basin and reuse for irrigations (food safety)

Reduce evaporation/transpiration losses

  • Irrigate during the evening, morning or night to minimize evaporative losses
  • Control weeds
  • Use plastic mulches and organic residue (cover crop residue) mulches
  • Convert to irrigation systems that wet less soil surface (furrow to drip, or sprinkler to micro-sprinkler)
  • Increase interval between sprinkler irrigations to reduce evaporative losses
  • Use short season and early season cultivars
  • Incorporate or kill cover crops between rows of permanent crops (trees and vines) before the cropping season
  • Time incorporation or killing of winter cover crops to conserve soil moisture for subsequent crop
  • Avoid the use of anti-transpiriants

Improve infiltration and water holding capacity of soil

  • Incorporate organic amendments to increase water holding capacity and macropore structure
  • Apply gypsum to minimize crusting of soil surface
  • Rotate with cereal crops (rye, barley, wheat) and/or deep rooted agronomic crops (corn, safflower, sunflower)
  • Correct drainage problems (install tile drainage, break impeding layers)

Optimize irrigation system design and operation

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Photo credit: CAWSI

General practices

  • Evaluate distribution uniformity of irrigation system
  • Audit operation and maintenance of irrigation system
  • Consult with an irrigation system designer
  • Check that irrigation system is operating at recommended pressure
  • Invest in more efficient irrigation system (eg. change from sprinkler to micro-sprinklers in orchard)
  • Train irrigators and irrigation foremen on maintenance and operation
  • Grade field to improve the uniformity of slope
  • Minimize or eliminate irrigation run-off
  • Fix leaks in main and sub main lines

Practices specific to micro-irrigation

  • Install pressure gauges or Schrader valves for monitoring pressure at water source, filter, submain connections, and lateral lines (drip hoses, drip tape).
  • Use pressure regulators at main-submain connections
  • Conduct regular maintenance to prevent clogging of emitters
  • Use the appropriate filter for water source and drip system
  • Repair leaks
  • Replace worn tape/ drip emitters/ micro-sprinklers
  • Limit elevation change along rows to less than 15 feet
  • Consider using pressure compensating tape/drip emitters/micro-sprinklers
  • Make sure main and submain line diameters are appropriate for flow rates

Practices specific to sprinkler irrigation

  • Use appropriate nozzle size for spacing of sprinkler heads
  • Check that the same sprinkler heads and nozzle sizes are used through out the field Irrigate at low wind speeds (< 10 mph)
  • Space lateral lines and sprinkler heads to optimize distribution uniformity
  • Replace worn nozzles
  • Replace worn gaskets
  • Replace sprinkler heads that leak or do not turn
  • Consider replacing impact sprinkler heads with rotator heads

Practices specific to furrow irrigation

  • Surge or pulse irrigate
  • Use torpedo to smooth furrows
  • Shorten length of furrow runs
  • Irrigate alternate furrows
  • Start with high application (intake) rates
  • Improve uniformity of slope
  • Cut-off water when flow reaches tail end of field
  • Re-circulate tail water to head of field

 Improve irrigation scheduling

Practices that can reduce water use

  • Apply appropriate amount of water for pre-plant and early season irrigations
  • Apply appropriate amount of water for germination and transplant establishment
  • Apply appropriate amount of water for salinity management
  • Record volume of water applied (flow meter)
  • Use a timer to automatically shut off pump
  • Consider using regulated deficit irrigation for tree and vine crops

Information to improve irrigation scheduling

  • Know crop water needs (daily evapotranspiration requirement)
  • Know the application rate of irrigation system (inches per hour, gallons per hour)
  • Know the rooting depth of the crop
  • Identify soil type and texture
  • Know water holding capacity of soil
  • Test salinity of irrigation water and soil
  • Understand water stress effects on crop growth, yield and product quality
  • Monitor soil moisture
  • Use tools for monitoring plant water stress (pressure bomb)
  • Use CIMIS or other weather stations for determining daily crop evapotranspiration requirements
  • Use irrigation scheduling software or spreadsheets to aid irrigation decisions

For more practical water-related resources like a PDF version of the checklist above, see our Water & Irrigation Toolkit.  

If you happened to miss them, check out the other articles in our Water & Drought Management Series:

If you have questions, words of wisdom or other great tips for the many farmers dealing with the drought, visit our Conversations and post a question or comment!

If you have other great water management resources to share, get in touch with me: evaa@farmsreach.com. We’d love to hear from you!

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