On-Farm Practices

Management practices, and their underlying technologies, together with land use decisions, have a dramatic influence on the total amount and ultimate fate of reactive nitrogen (N) in the environment

To date we have answered questions about N application rate guidelines and relevancy, and are currently analyzing the nitrogen use efficiency of various cropping systems. Our preliminary results tables provide insight into our nitrogen use efficiency work to date. We seek stakeholder input in providing data and numbers to flesh out this analysis.

Nitrogen Use Efficiency Data Sets

We are undertaking our analysis of nitrogen use efficiency by crop (see preliminary results) with the data accessible to us, but are also seeking additional unpublished data from commodity boards, farm advisors, crop advisors, and anyone who has information that might help answer questions on nitrogen practices in California. Specific data needs are outlined below.

Information sought:

  • Data on nitrogen sources, rates, timing of applications for your commodity—both the average and the distribution (e.g., most producers use 150 lbs. N / acre and 75% of the producers use at least 125 lbs. N / acre).  We also seek survey data, if you are aware of any surveys that have been conducted on N management practices within your specific commodity.
  • Results of nitrogen rate trials that use a range of fertilizer treatments, a zero-N treatment, or isotopic N (15N).   
  • Information regarding interactions between nitrogen management and other farm operations or marketing considerations (e.g., irrigation and nitrogen management are closely related in some vegetables or excess nitrogen decreases postharvest longevity in some fleshy fruits).
  • Information on practices and technologies used to manage nitrogen in your commodity (e.g., the majority of producers use petiole sampling to determine nitrogen needs).     
  • Information that producers within your commodity might consider when thinking about the fate of nitrogen and soil management (e.g., some crop producers market additional by-products that contain nitrogen, such as almond hulls). 

Questions/Comments: Contact Todd Rosenstock, Best Practices and Technical Options Fellow, trosenstock@ucdavis.edu.