Detailed chemical composition of pig feed and manure.

The analysis of the composition of pig manure for 22 elements enabled us to quantify its fertilising potential and toxicity hazards for the quantities usually spread. On the basis of 170 kg of nitrogen per hectare the input was approximately 100 kg of P2O5, 170 kg of K2O, 140 kg de CaO, 50 kg of SO3, 35 kg of MgO and Na2O, which compensated for all or part of the nutrients lost in harvested crops or through leaching.The manure also helps provide trace elements that may be deficient, such as iron, boron, copper, zinc, molybdenum and manganese.