Growers rated the need for research to discover methods to meet environmental standards highly. To this end, the interdisciplinary nutrition work under way is addressing the fate of applied nitrogen in water and air. This component is being supported jointly by the ABC and others, including farm bill grant funds. One key finding is that current practices of micro-irrigation combined with fertigation can yield 70 percent to 80 percent nitrogen use efficiency (NUE), which is among the most efficient ever measured in agriculture.

NUE is calculated as the nitrogen applied vs. nitrogen removed with the crop (kernels, shells and hulls). This NUE was obtained by applying total N in the range of 250-275 pounds per acre in a high yielding orchard through microsprinklers or drip, making several runs of 25 to 60 pounds each in February, March, April, May and June to match demand during growth and fruit development.

While almonds are a high-nitrogen-use crop, this high efficiency approach matching in-season demand has led to low off target movement of N. For instance, monitoring demonstrates nitrates did not move out below the root zone while air monitoring shows off-gassing of nitrous oxide (N2O) is much less than originally estimated. N2O is one of three major greenhouse gasses.

The article, “Survey examines the adoption of perceived best management practices for almond nutrition,” is available online at californiaagriculture.ucanr.org/.
For more information on almond orchard management, visit almondboard.com/farmpress11.