California Agriculture

Many of the dairies in California’s Central Valley use a water flush system for manure handling; the manure water is eventually mixed with freshwater and applied to cropland during irrigation. Good performance during irrigation applications is important due to the nutrients in the manure water. This project evaluated alternative management techniques (furrow torpedoes, surge irrigation and shortening furrow lengths) for improving irrigation practices on dairies. All three techniques reduced the amount of water required for irrigation. The project also investigated the impact of changing the timing of manure-water additions to the fresh irrigation water. Delaying the addition of manure water until the advancing fresh irrigation water had reached approximately 80% of the distance down the field improved nutrient-application uniformity and reduced nutrient applications.