Nitrate in Tile-Drain Water Relative to Time and Source of Nitrogen Application

summary

Sound nitrogen (N) management is a key component to minimizing environmental degradation and improving farmer’s profitability. Nitrogen fertilization in agricultural lands in much of the Midwest has been linked to water quality issues related to the hypoxia zone in the Gulf of Mexico. Currently, Minnesota and other Midwestern states have or are developing Nutrient Reduction Strategies to reduce nitrate loads. While we have learned much about some of the practices that can help us achieve reductions in nitrate loads to the Mississippi river, still there are many uncertainties on how well some N management practices work. Further, other practices, such as in-season applications, split pre-plant plus sidedress applications, or the use of controlled release fertilizers, have not been evaluated to truly determine their value for agronomic and water quality goals. It is clear that substantial research efforts are needed in order to provide meaningful and reliable guidance to enhance agricultural productivity in Minnesota while protecting the environment.

Nitrogen is extremely important for optimizing corn yield as this crop has a large requirement for this nutrient. At the same time, N is important from an environmental standpoint as this nutrient can have profound negative impacts on environmental quality when introduced into surface- and ground-water or the atmosphere in the form of nitrous oxide. Nitrogen fertilization in agricultural lands in much of the Midwest has been linked to water quality issues related to the hypoxia zone in the Gulf of Mexico. Currently, Minnesota and other Midwestern states are developing Nutrient Reduction Strategies to reduce nitrate loads by 45% by the year 2045. In order to achieve this lofty goal, much needs to be done with research to determine how effective various traditional and new N-management practices are.