High precipitation and minimal crop demand for water in the spring makes for perfect conditions for water to move quickly through the soil profile, taking nitrogen with it. Although we cannot control the weather, there are a few management practices, including application timing, that can help prevent excess nitrogen losses in the spring, says the University of Minnesota.

Careful manure management is a principle of farm profitability and environmental stewardship. Applying manure to land that has a cover crop is another practice that can help with nitrogen management.

While the soil nitrogen cycle is very complicated is it extremely hard to measure exactly the amount of nitrate that should be in the soil from fertilizer or manure N applications. However, we can get an idea if leaching has occurred by evaluating the concentrations of nitrate-N by soil depth.

A recent study from University of Minnesota, with support from Pope County SWCD and the Minnesota Department of Agriculture, evaluated the use of winter rye as a cover crop in corn production.

Purdue University Extension offers recommendations on further nitrogen applications based on results from recent soil samples.

It's difficult to estimate how much nitrate-N is lost from the root zone, but soil sampling and measuring the concentration of nitrate- and ammonium-N remaining is an alternative to guessing.