IN-FIELD PLANT MONITORING AS A TOOL FOR N MANAGEMENT IN SMALL GRAINS

3/4/2015 4:11:23 PM

UC Cooperative Extension, Plant Sciences Department, University of California, Davis, CA 95616

Mark Lundy, Steve Wright, Steve Orloff, Robert Hutmacher

In order to develop guidelines for optimum N management in the Sacramento Valley, the objectives of this research were to: 1) establish multirate, split-application N fertilization trails on representative varieties of wheat in the Sacramento Valley region; 2) measure the N status of the plant-soil environment at key crop developmental stages using low-cost, in-field methods; and 3) develop decision support thresholds that relate the in-field diagnostic measurements to likely yield and protein responses. The results to date demonstrate that 1) split-applications improve yield, protein and N use efficiency outcomes with applications of N at tillering being more valuable in terms of N use efficiency than pre-plant applications; 2) late-season applications can boost grain protein content if the crop has sufficient protein yield potential; and 3) in-field diagnostic tools can indicate whether the crop is likely to respond to an in-season N top-dress.

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