Abstract: A sensing-based process for managing nutrient fertilization in crops. This invention uses reference plots in a field, fertilized at different pre-plant rates, including at least one plot fertilized at a lower rate than the majority of the field. Measurements from the plots are used to estimate the Current Limiting Rate (CLR), which is the lowest non-limiting nutrient rate at the time of sensing. Preferred embodiments are presented specifically for managing nitrogen in rain-fed and irrigated corn. These embodiments use the CLR, along with a model for CLR movement with time to determine nutrient rates for mid-season treatments that achieve specified yield-based or profit-based objectives. This invention's novel use of low-rate reference plots to estimate the CLR enable the detection of stress before the main area of a field is impacted, allowing for advance planning and intervention without sacrificing yield potential.

Abstract: A self-contained UAV sensor payload and on-board or off-board hardware and software for precision agriculture. The invention combines multiple cameras and navigation sensors to create a system for automatically collecting, geo-referencing, and stitching red, green, blue, and near infrared imagery and derived vegetation indices. The invention is able to produce all of these quantities in a single flight. The tight integration with integrated navigation sensors eliminates the need for integration with external sensors or avionics hardware and enables innovative solutions to image processing and analysis which greatly improve accuracy, processing speed, and reliability over alternative approaches.