In Belgian beef production systems, finishing beef stables are bedded with straw, resulting in a solid manure that is classified as such, i.e., having a dry matter content of minimum 20%. In the previous MAP legislation, in wintertime, it was mandatory to store manure in a concrete pit with collection of effluent. Storage on field was not allowed. For this, ILVO did research on different possibilities to reduce nutrient losses and enhance product quality by improvement of the storage conditions of manure on field. Due to this research, it is now allowed to store manure on field in wintertime when it is covered, however, only the amount that will be used on that specific field.

ILVO did a trial at different sites, looking at the effects of just dumping versus composting manure, the latter by adding “brown residues” (chips from prunings, vegetation cuts from natural reserves) to the manure and looking at the effect of covering the piles, either by airtight sealing or semipermeable fleeces. Different combinations were tested, and none of them showed substantial N leaching losses towards the soil, a maximum of 4.2% N , compared to the initial N content of the stored manure. The most important factor to consider is the composition of the manure. Depending on the moisture content of the manure, a different treatment is advised.

It is not recommendable to turn wet, dense manure with a low amount of straw, using a windrow compost turner. This will increase N losses by volatilization and leaching. A farmer should just dump it on the field and cover it, preferably with semipermeable fleece (e.g. geotextile).