Deciding when and how much water to apply to a field has a significant impact on the total amount of water used by the crop, on water-use efficiency and on irrigation efficiency. A number of different scheduling systems have been developed that can use either soil-plant or atmosphere-based measurements to determine when to irrigate. Using a more scientific approach to scheduling has generally been shown to decrease the amount of water used while improving yield.
Tailwater Return Systems
To provide adequate water to the low end of the field, surface irrigation requires that a certain amount of water be spilled or drained off as tailwater. Tailwater return systems catch this runoff and pump the water back to the top of the field for reuse.
Irrigation System Improvements
Irrigation system improvement involves modifying the irrigation method or using computer hardware and software to properly apply water to the field while minimizing water losses. Examples include improved furrows, a combination of furrows and sprinklers and changing from surface irrigation (flood, furrow and border check) to pressurized systems. Changing from surface irrigation to pressurized systems (sprinkler, drip, microirrigation) generally increases water distribution uniformity and decreases applied water, although with certain soil types and applications, surface irrigation can be very efficient. California has seen a trend to shift from surface irrigation to pressurized systems.
The LSU AgCenter and the LSU College of Agriculture