Non Technical Summary
This project will develop a plant-by-plant, precision fertilization capability for cool season vegetable crops that will increase harvest yields while reducing the overall amount of fertilizer applied. Vegetable growers face increasing pressures to reduce their fertilizer usage from rising fertilizer costs, tighter environmental regulations and consumer-driven demands for sustainable food production. Also, given typical plant size variations in a field, a significant fraction of plants is discarded at harvest because they do not meet buyer specifications. Our innovation applies varying amounts of fertilizer to different sized plants and uses precision targeting of plant locations. It thereby increases plant uniformity across the field, increasing effective crop yields, reducing food waste and conserving fertilizer.Multiple trials will be conducted in commercial lettuce fields, building upon trial methodologies developed during the Phase I proof-of-concept. Objectives include refining proof-of-concept sprayer hardware for in-field trials, optimizing fertilizer application amounts and timing, developing a prototype set of scalable system components and processes, and validating system scalability. Using commercial production fields for trials, grower teams will participate in early use and provide essential feedback to ensure integration of the new approach with daily operations. The resulting capability will require a relatively simple and inexpensive retrofit of growers' existing fertilizer toolbars. It will be sold as an add-on to subscription services we have already developed and commercialized for the fresh produce industry. The complete system will help growers better coordinate their fertilization with irrigations towards optimizing their nitrogen use efficiency.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
402	1430	2020	100%

Knowledge Area
402 - Engineering Systems and Equipment;

Subject Of Investigation
1430 - Greens and leafy vegetables;

Field Of Science
2020 - Engineering;

Goals / Objectives
Configure equipment for refinement of fertilizer variable rate application (VRA) during Phase II experiments.Refine fertilizer application amounts and timing and demonstrate repeatable results for the VRA application techniques.Establish a scalable set of system components and processes.Validate system scalability through in-field trials.Refine the system cost-benefit analysis for commercialization.

Project Methods
Configure hardware for Phase II field trials.Design and Conduct Phase II field trials.Integrate VRA into grower operations.Evaluate system costs and effectiveness based on Phase II trials.Prepare a final report.