Resources

General Management

• CropManage - A comprehensive irrigation and nutrient management decision support tool that utilizes CIMIS and UC research to calculate crop-specific fertilizer and irrigation needs. For guidelines and updates, visit the CropManage Blog. (UC ANR; Michael Cahn)

• Nitrogen management training modules for Certified Crop Advisors - Collection of learning modules created with support from the California Department of Food and Agriculture in order to help growers develop efficient nitrogen management practices.The training was offered to Certified Crop Advisors (CCA) around the state. (UC ANR)

• What's in your nitrogen budget? - Summary of the key components of a nitrogen budget. (Internation Plant Nutrition Institute)

• Nitrogen management plan worksheet instructions - Sample nitrogen management plan worksheet annotated with descriptions of each section and recommendations of data sources that can help with the calculations of each section. (Central Valley Regional Water Quality Control Board

• Approved farm evaluation plans for growers - Approved farm evaluation plans, nitrogen management plans, and more from the 14 water quality coalitions in California. Also includes a map of the water coalition boundaries and forms to join a coalition group. (Irrigated Lands Regulatory Program)

• The California Nitrogen Assessment: Challenges and Solutions for People, Agriculture, and the Environment – The first comprehensive account of nitrogen flows, practices, and policies for California, encompassing all nitrogen flows—not just those associated with agriculture—and their impacts on ecosystem services and human wellbeing.

• Russell Ranch Agroecological Research – At Russell Ranch, long-term monitoring and experimentation assess the sustainability of agricultural production. Faculty and researchers to conduct a variety of experiments with access to a wide collection of supporting data. Data collection includes water and fertilizer inputs, yield, weather events, pest pressure, soil microbiology, energy use, and more.

Testing

• Soil sampling instructions
  (UC Davis in collaboration with Fertilizer Research and Education Program)

• Soil Sampling Video Series
  (Fruit & Nut Research & Information, UC Davis)

• Details on nitrate quick test
  (UC Cooperative Extension - Richard Smith)

• Economic benefit of pre-sidedress soil nitrate testing
  (Natural Resource Conservation Service)

• Guide to nitrogen test for vegetables with the ‘Cardy’ Nitrate meter 
  (UC Cooperative Extension - Kurt Schulbach, Richard Smith, Tim Hartz, Louise Jackson)

Nutrient Budgeting

• Crop nutrient harvest removal - Discusses considerations in calculating nutrient concentrations, including adjusting for different moisture contents. Provides a table of typical yields and nutrient concentrations for common grain/forage crops. (UC Manure Technical Guide Series)

• Crop uptake and partitioning - A generalized pattern of seasonal N uptake for several commonly grown crops. Includes results of research on nitrogen partitioning and the amount of N removed at harvest. (UC Davis in collaboration with Fertilizer Research and Education Program)

• Manure nitrogen mineralization - An overview of the basics of N mineralization from manure, reasons for variability in manure N content, mineralization rates and considerations in predicting N availability from manure over time. Provides calculations to estimate plant-available nitrogen for animal manures. (UC Cooperative Extension Manure Technical Bulletin Series)

• Nitrogen in organic matter and mineralization rates - Part of the Field-Specific Nitrogen Fertilizer Adjustments, clarifies N credits from organic materials. Includes specific information on mineralization rates of organic matter, crop available N from legume cover crops, crop residues, alfalfa, manure and more. (UC Davis in collaboration with Fertilizer Research and Education Program)

• Crop nutrient removal calculator - Calculator for how much nitrogen, phosphorus and potassium is removed when specific crops are harvested. (Natural Resources Conservation Service)

• Nut orchard nitrogen calculator - Calculates nitrogen fertilizer recommendations accounting for N credits including irrigation water, cover crops, compost and other sources. Must create and account with sustainablealmondgrowing.org to access. (Almond Board of California)

• Nitrogen Budgeting Worksheet for Walnuts - Calculates an N budget accounting for past yield data, irrigation records, nitrate in irrigation water, compost, and manure applications as well as cover crops. (UC Agriculture and Natural Resources; Kathy Kelley and Joe Grant)

Irrigation Management

• Wateright irrigation scheduling - An online resources for scheduling irrigation using Evapotranspiration data from the California Irrigation management Information System (CIMIS). (Center for Irrigation Technology at California State University, Fresno)

• Irrigation (Fresh) water sampling protocol - Although this protocol is specific to irrigation associated with milk cow dairy operations, it provides a good framework for the sampling of irrigation water in general. (California dairy Quality Assurance Program)

• Nitrate to nitrogen conversion/ Estimating N from irrigation water containing nitrate - Provides conversion factors from ppm of nitrate in a water sample to pounds of N per acre-inch or acre-foot. Discusses how much of the N in water should be credited to the crop and gives an example of calculations that can be made to come up with an estimate. (UC Cooperative Extension; Michael Cahn and Richard Smith)

• Evaluating water quality - A guide for self-assessment techniques for evaluating water quality. Covers several parameters of water quality including a section on testing for nitrate. (UC ANR)

Fertilizer Management

• Published UC nitrogen fertilizer rate guidelines for select crops - Table from Nitrogen fertilizer use in California: Assessing the data, trends and a way forward, published in California Agriculture. (Rosenstock et al. 2013)

• California Fertilization Guidelines for Major Crops - Fertilizer Guidelines for main field and tree crops grown in California, based on research carried out in California and elsewhere. (UC Davis in collaboration with Fertilizer Research and Education Program)

• Field-Specific Nitrogen fertilization adjustments - Explores the factors to make adjustments to fertilizer guidelines based on field-specific conditions including expected yield, weather, soil and crop management. (UC Davis in collaboration with Fertilizer Research and Education Program)

• Nutrient Source Specifics (Fertilizer fact sheets) - Fact sheets on the specifics of commonly used fertilizers and nutrient sources. (International Plant Nutrition Institute)

• Nitrogen Fertilization Recommendation for Almond (Model) - Calculates N requirement for almond production based upon the yield history, current conditions and previous N applications. Can be used to calculate timing and rate required to maintain optimal yield. (UC Cooperative Extension)