Due to the new fertilizer ordinance, the use of fertilizers must be reduced in many places in the future. Stabilizing nitrogen can help make fertilizing more efficient. We show what nitrogen stabilization means and how it works.
Nitrogen (N) is one of the most important nutrients for the plant. Cultivated plants need it, for example, to produce wheat grains and other protein-rich crops.
Most of the world’s N is only present in the atmosphere as atmospheric nitrogen. It is not available to plants – except for legumes . Most plants can only absorb nitrogen in the form of ammonium (NH4 +) and nitrate (NO3-) through the roots. The plant can absorb nitrate particularly easily, but it is more volatile and is easily lost through washing out.
Ammonium cannot be washed out, but it can be quickly converted into other substances. Soil microbes can convert ammonium into nitrite and then nitrate within a few days. Part of the ammonium and nitrate is converted into laughing gas (NO2) during the reactions, which rises into the atmosphere. Not only is this harmful to the climate, but nutrients are also lost from the soil . It is also inefficient and costs money.
Heat accelerates nitrogen conversion
An exception among the mineral N fertilizers is urea. The plant cannot absorb it directly. It must first be converted into ammonium. Some can be lost as ammonia. This reduces the N efficiency.
Various soil microbes are responsible for the conversion processes. How active they are depends, among other things, on the temperatures. The soil organisms are very active, especially in a warm environment. Within a few days they can convert urea into ammonium and ammonium into nitrate. The availability of water also influences chemical processes.
Additives maintain plant availability
The industry has recognized these fertilizer efficiency problems and offers various means of stabilization. This should keep the nitrogen in the desired form for longer. There are two different mechanisms for this: the nitrification inhibitors and the urease inhibitors.
The latter must be added to urea fertilizers today. They inhibit the conversion of urea to ammonium or ammonia. Nitrification inhibitors slow down the next step in the conversion of ammonium to nitrate. This also makes them useful for organic fertilizers containing ammonium and fertilization under the roots. The transformation processes can only be slowed down, not stopped.
Urease inhibitors give the plant around ten more days to absorb the urea nitrogen; Nitrification inhibitors even keep the ammonium for six weeks. This means that the plant’s nitrogen is available longer. This way, gifts can be summarized and crossings saved. The nutrients reach the roots safely even in dry conditions; Groundwater inputs and emissions are falling.
