It is generally true that forage yield increases when the water supply is controlled. In areas where rainfall is deficient or erratic this is obvious but even in areas where annual rainfall is sufficient, controlling the timing of the water is advantageous. But it is also costly so maximum benefits are only achieved when water is used efficiently. Efficient irrigation depends on a balance between the atmospheric and edaphic (soil) conditions. Atmospheric precipitation and evaporation play important roles as does the water-holding characteristics of the soil. The selected forage species will also add new characteristics that influence water utilization and efficiency, like root depth. A producer must be well acquainted with how these function on his/her land.

The following list may help a producer evaluate water use:

  • When is the best time to irrigate?
  • How often and in what intervals should I use during establishment, germination, and weed control or just during main growth and regrowth periods?
  • What type of system would work best for my operation, surface or pressurized (sprinkler, drip)?
  • What layout design is most efficient?
  • What type of soil will be irrigated? How is the soil compacted and aerated?
  • How far does the water need to be brought?
  • What is the cost of the water and equipment to distribute the water?
  • What type of crop will be irrigated? What is the age and condition of the crop?
  • What are the weather conditions and patterns in this area?
  • What are the requirements for leaching to prevent salt buildup?
  • What other interactions are affected by irrigation?

Probably the most important part of a successful irrigation system is management. The system can only be efficient when all factors are carefully considered since irrigation is part of a complex relationship. The manager has many ways to improve efficiency if knowledge and observations are acted upon quickly. And managers need to be vigilant during the entire growing season. For most situations crop yields maximize when soil moisture is high continuously throughout the growing season. Stressed plants do not use water more efficiently than well-watered plants. The goal is to schedule irrigation to maintain a non-stressed soil-water environment throughout the growing season while preventing water losses, leaching of salts and fertilizers, and loss of root aeration. Forage crop irrigation schedules must match the specific situations. The manager must determine the match.

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