Recent concerns about hypoxia in the Gulf of Mexico have inspired policy makers to encourage the agricultural sector to adopt technology that can reduce nitrogen losses in our environment.

And as fertilizer prices increase, savings in fertilizer application can help offset the cost of investing in precision-ag technology. This technology gives us the tools to apply nitrogen at different rates throughout the field as soil conditions change.

The biggest challenge is determining what rate should be applied, so I recently wrote a Conservation Innovation Grant with Dr. Matt Ruark, assistant professor at the University of Wisconsin’s Department of Soil Science, and Dr. Tom Cox, professor at the university’s Department of Agricultural and Applied Economics.

The purpose is to demonstrate and learn how we could use precision technology to improve nitrogen-use efficiency and reduce nitrogen losses.

The project will demonstrate how to utilize precision ag and onfarm research technology to develop nitrate management zones (NMZs) and vary nitrogen rates — on a site-specific basis — to reduce nutrient losses and improve farm profitability.

Developing NMZs

A key to developing variable-rate nitrogen prescriptions is defining different soil and management regions within a field — which we call NMZs. The zones can be used in combination with yield and weather information to develop nitrogen prescriptions.

To develop NMZs we’ll use new technology to evaluate a variety of variables, such as soil type, soil organic matter, soil texture, water-holding capacity and CEC. Then we’ll look at soil-nitrate tests and nitrogen-use efficiency (NUE) through whole-plant…