Farmers can improve irrigation efficiency by understanding the environmental factors that affect their operation and by using technology to make better decisions, experts with the LSU AgCenter and National Resources Conservation Services said at a recent workshop.
Temperature, humidity, solar radiation and wind speed affect how much water plants consume. Consider those environmental factors when irrigating to adequately provide water to crops, says AgCenter weed scientist Josh Copes. Soil type is another factor.
As crops near maturity, check that the soil profile is full of water before stopping irrigation. Scheduling irrigation minimizes soil and nutrient losses and improves yields, says AgCenter irrigation engineer Stacia Davis. Soil type affects how water moves. “Sand has much larger particles, resulting in larger pore spaces, so it can’t hold much water because it’s going to move through very quickly,” Davis says. Silty loam and clay soils hold water for a longer time.
Flow meters, which monitor how much water flows through the pipe, are useful tools. Soil moisture sensors help farmers decide if they need to irrigate. Many different types are available, including some which yield data that can be viewed remotely online or using a smartphone app.
Surface Water, Furrow Irrigation
Surface water is typically less expensive to pump. But not everyone has easy access to a body of water and must draw groundwater from a well. Some surface water bodies, such as bayous, fluctuate more than others. When the water level is lower, it must be lifted a greater distance, which uses more energy. A handheld tachometer, or RPM gauge, is a valuable tool for testing pump efficiency.
In furrow irrigation, the number and size of holes in poly irrigation tubing affect efficiency. Computerized hole-selection software, including PHAUCET and Pipe Planner, determines the best way to punch holes using data that farmers upload.
NRCS agronomist Chris Coreil said the agency offers financial assistance to producers who want to try new practices and technologies, including tailwater recovery systems, surge valves and cover crops.
Salinity in irrigation water is a growing problem in Louisiana, says AgCenter water quality specialist Changyoon Jeong. In clay soils that hold water, salt accumulates on the surface at the beginning of the irrigation period, which harms soil health. In sandy soils, the salt leaches into the ground and pollutes groundwater.Farmers can send soil samples to the AgCenter soil lab to determine how much salt it contains.
James Hendrix, AgCenter northeast area agent, says the Louisiana Master Farmer Program helps producers voluntarily implement practices that reduce runoff and make more sustainable management decisions.
LSU AgCenter contributed this article.