Farming systems are getting more and more refined each year.
Farming systems are getting more and more refined each year. Many of the problems that have plagued production agriculture through the years are beginning to become a thing of the past because of new innovations that have come down the pike over the least ten years. The result is more production on the same acres.
One of the most formidable problems farmers have faced over the years is the loss of nitrogen from the soil profile after the crop has been planted. It is a particularly troublesome problem for farmers in this area of Kansas. The chief culprit for this is the waterlogged clay pan soil in our area. Water drains through this clay layer so slowly that soil can remain saturated for weeks. This is where the problem starts.
Waterlogged soils have little oxygen available so that the respiration of soil microbes is
curtailed until such time as the water drains away and oxygen returns. However, there are certain bacteria in the soil that get around this oxygen scarcity by disconnecting the oxygen atoms from a nitrate (NO3) molecule and utilize that oxygen for their own purposes. Plants take up nitrogen in the nitrate form and cannot utilize the elemental form of nitrogen which is all that remains after the oxygen has been removed from the nitrate molecule. This can lead to a severe nitrogen deficiency in the crop which ultimately can create a serious reduction in yield.
Researchers have been wrestling with this problem for years and it is just nearly impossible to stop this loss with cultural practices. For years, it has been the goal of researchers to come up with a nitrogen source that prevents this loss.
In a perfect world, a nitrogen source would convert to the plant available form very slowly. This would prevent the loss of nitrogen since only a small amount of available nitrogen would be present at any given time. This would prevent the loss that occurs when all of the nitrogen converts to a plant available form in a short time span.
Currently, there are at least two approaches to achieving this goal. The first is to prevent the nitrogen source from converting to nitrate quickly by mixing a urease nitrification inhibitor with the nitrogen source. This greatly slows the nitrification process, meaning that the conversion occurs over a longer period of time giving the plant a greater opportunity to pick the nitrogen up before it has a chance to escape.
The other process is with the use of a polymer that coats the urea nitrogen source. Water can readily penetrate this polymer coating but the nitrogen must diffuse back through this polymer coating which happens slowly. This polymer coating varies in thickness with the thicker coating retaining the nitrogen longer. This means that the nitrogen will become available over a longer time period. Once again, this will allow the crop to sponge up the available nitrate before the nitrate reducing bacteria have a chance to use it for their own purposes.
So both of the approaches above are designed to slow the rate at which applied nitrogen is converted to volatile nitrate. This means that little nitrate will be available for loss during periods of saturated soil conditions. So the end result is more nitrogen available to the plant over a longer period of time. This should equate out to higher yields.
Farmers will probably find that in dryer years, there won’t be much of a yield boost because during dryer years, the condition responsible for nitrogen are much less likely to occur. However, during wet years there could be a very significant yield increase.
Doug Shoup, Southeast Area Extension Agronomist and I have put out a couple of plots to test the ability of the polymer coated urea to increase yields. We have one of these plots in wheat and the other will be in corn. It should be very interesting to see what happens.