WHAT’S THE BEST SOLUTION FOR NITROGEN MANAGEMENT CHALLENGES?
From Richard’s desk:
As I mentioned in my last nitrogen blog, for various reasons nitrogen is a difficult nutrient to precisely manage. Crop available nitrogen or nitrates are mobile nutrients that do not attach to soil particles. Because nitrates are soluble, any time water moves through the soil, nitrate will move with the water making them unavailable to crops. In our area, this also causes environmental issues as nitrates build up in the groundwater.
Crops obtain nitrogen from a variety of sources, in addition to fertilizer. Legumes get a large share of nitrates from symbiotic bacteria and corn obtains a large amount of nitrate from organic sources in addition to fertilizer. Over 95% of the nitrogen in the soil is organic nitrogen, primarily in organic matter. While organic nitrogen is not usable by the crop, it does mineralize into nitrates which is usable. The rate this mineralization takes place is weather dependent. Warm weather increases the rate, cool weather slows the rate.
There is also a great deal of spatial variability in almost all fields. Field characteristics such as soil texture, soil organic matter, and topography also affect nitrogen availability.
Nitrogen management methods need to take these factors into account and most methods have difficulty doing so.
Over the past few years, we have been working with UNL on a method that takes these factors into account. Next year we are working with Sentinel Fertigation to make this technology available to farmers in this area.
