Zunhammer Van-Control 2.0: For a long time, the use of near-infra-red sensors (NIRS) has been discussed with regard to the determination of substances in liquid manure. The DLG testing commission "fertilizing technology" has now developed a test framework, and the DLG test centre has carefully examined the first manure NlR sensor.
Even as stall manure was the basis of nutrient supplement and the conservation of soil fertility for centuries, the use of mineral fertilizers in agriculture increased dramatically with the progress in the natural sciences. There are therefore quite a number of farms, and in particular pure arable farms in Germany, that supply their field crops exclusively with minerals.
On the other hand, there has been an almost blanket move from solid dung to liquid dung as technology has progressed in cattle breeding. In addition to cattle and pig manure, digestate from the biogas production has now also become a factor in recent years for use as farm fertiliser.
All farm fertilisers are complex fertilizers, a valuable supplier of organic substance for the formation of humus.
Thanks to their nutrient content and the fact that they are cost-effective and - especially in areas with high stocking density - are available in large quantities, slurry and digestate actually gain in importance, especially due to the rising prices for mineral fertilizers. However, arable farms want to exploit the legal limit of 170 kg of nitrogen per hectare in Germany as optimally as possible to gain the best possible yields and qualities of their crops. Although both manure forms can be spreaded with a similar distribution accuracy (at least at the technical level), not quite a few farms decide against the use of farm yard manure.
This is because their nutrient contents, many of which are not known exactly, often remain inhomogeneous even after a long stirring processes, while mineral fertilizer has a defined nutrient content. Added to this is the fact that time-consuming wet chemical processes must be applied to accurately determine the nutrient content in farm fertilizers, and sampling and processing
is a science in itself, and may contribute to a high level of measurement inaccuracy of the calculated nutrient content.