Raj Khosla will be presenting his 2020 data from the project “Precision Nitrogen Management Strategies to Increase Profitability and Sustainability of Irrigated Cropping Systems”

In traditional farming systems farmers choose to manage nitrogen (N) fertilizer at a uniform rate across a field based on an average yield goal. Dr. Steve Stokes, the opening Keynote speaker at a recent Info-Ag conference made a profound statement: “When you manage the “average” you miss your target 100% percent of the time”. Management decisions based on the field average results in significant over and under-application of N in a majority of the field. There is strong evidence that spatial and temporal variability exists in crop yield and hence N distribution and availability to plants (i.e., variability across the field within a given growing season and variably over time for a given field location). While this poses a challenge it also provides an opportunity to quantify, record, and manage N fertilizer both spatially and temporally.

There are opportunities in irrigated cropping systems to take advantage of precision N management from pre-plant N application through mid- to late-season N application. It is well documented that the efficiency of N fertilizer is reduced when farmers use a single application (either pre-plant or at-planting). This is due to the higher potential of N losses when N is in the soil solution prior to when the plant needs it. Split applications of urea ammonium nitrate (UAN) fertilizers can address temporal variability in crop needs and enhance N use efficiency while reducing N loss in the biosphere.

Fluid fertilizers are easy to apply for farmers and give versatility for optimal spatial and temporal management.

The overall objective of this research project is to increase the productivity, profitability, and sustainability of irrigated cropping systems in the western US. Specific subobjectives are:

i. To quantify improvements in crop yield and N use efficiency—among single and multiple (split) applications of fluid N fertilizers—resulting from the implementation of a precision N management strategy comprised of management zones coupled with in-season crop sensing to address spatial and temporal sources of variability.
ii. To quantify improvements in average net returns and the variability of net returns—also among single and multiple (split) applications of fluid N fertilizers—resulting from the implementation of a precision N management strategy comprised of management zones coupled with in-season crop sensing to address spatial and temporal sources of variability.

0.5 units of CCA Sustainability Credits are available

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