These models calculate the nitrogen (N)  and potassium (K) requirement for pistachio production and N requirement for almond production. These models are based upon yield history, current conditions and previous applications, and can be used to calculate both timing and rate of fertilizer application required to maintain optimum yield.

• Nitrogen Fertilization Recommendations for Almond
  P. H. Brown and Q. Zhang, Department of Plant Sciences, University of California Davis, Max Stevenson, UC-SAREP program, and R. C. Rosecrance, College of Agriculture, California State University Chico
   
• Pistachio Nitrogen (N) and Potassium (K) Fertilization Models
  R. C. Rosecrance, College of Agriculture, California State University Chico, and  S.A. Weinbaum and P.H. Brown, Department of Plant Sciences, University of California Davis

Almond Nitrogen Nutrition Using the Internet-Based Fertilization Program (PowerPoint to pdf)
Patrick H. Brown, Steve A. Weinbaum and Farbod Youssefi, Department of Plant Sciences, University of California Davis. 2004.
This 23-slide Power Point presentation describes the internet-based fertilization program