Application of Mineral Concentrates from Processed Manure

Manure is a valuable source of nutrients for crops. This chapter presents an overview of the nitrogen fertilizer replacement value of mineral concentrates from processed manure, based on a series of studies carried out in the Netherlands. It provides an assessment of the fertilizer value of manure concentrates on the basis of the composition. The chapter also presents nitrogen fertilizer values obtained in pot and field experiments and discusses nitrogen losses from mineral concentrates as ammonia, nitrous oxide, and nitrate. The risk of ammonia emission from applied mineral concentrate is probably higher when applied to soils containing lime than to neutral or acidic soils, as is the case for any other ammonium‐based mineral fertilizer. Application of mineral concentrates may strongly increase concentrations of ammonia in the soil. Ammonia is toxic for nitrifying organisms. A high ammonia concentration in soil may thus inhibit nitrification, leading to the production of nitrite and nitrogen oxide.