Strides have been made not only in timing and application method, but also in the amount of N applied.  ABC-funded research has demonstrated the primary factor dictating N use is crop potential — the total amount applied should be matched to the crop (hulls, shells and kernels) removed with harvest.  Over-fertilizing that exceeds this guideline does not enhance yields.

Adopting and applying these principles, almond growers have increased both yield and nitrogen use efficiency.

Two decades ago, the state average yield was 1,200 to 1,300 pounds per acre on a typical nitrogen application of 200 pounds applied N per acre. That is a nitrogen use efficiency of about 44 percent. In contrast, recent results from research conducted by UC researchers demonstrate a yield of 4,000 pounds with 275 pounds of N per acre.  That is a nitrogen use efficiency of 75-85 percent, which was attained using current industry practices. This research also documents minimal losses of N: percolation below the root zone averaged less than 5 percent and volatilization was much less than 1 percent.

Almond growers continue to look for ways to even further enhance their nitrogen use efficiency. Programs for continuous improvement, such as the California Almond Sustainability Program, highlight and encourage nitrogen and irrigation management strategies that optimize yield while minimizing impacts to the environment and natural resources.

More research results coming

Research funded by the Almond Board will continue to give growers the tools they need to make improvements. Better information and guidelines, such as new in-season leaf sampling protocols and improved N budgets and models that will offer growers more meaningful and actionable results are on the horizon.

Nitrogen use will continue to be a high-profile public health issue in the San Joaquin Valley. The Almond Board is dedicated to being part of the ongoing discussion to finding workable solutions to providing safe drinking water.

The State Water Board will hold a public workshop on the issue in Sacramento on May 23. The UC Davis report and input from the workshop will be used to inform the board as it develops recommendations for its report to the legislature later in 2012.

Find more information on the May 23 workshop and the UC report, “Addressing Nitrate in California’s Drinking Water”at AlmondBoard.com/farmpress26.