Methods for the recovery of nutrients and energy from swine manure. 1. Biogas.

The recovery of nutrients from pig manure (300 l/day discharged by 100 pigs) during digestion for biogas production amounted to 1435 kg N, 350 kg P and 490 kg K per year. When spread on the 15.26 ha of land required to grow the corn and soybean for the pig ration, each hectare would receive 94 kg N, 23 kg P and 32 kg K per year. The energy value of the recovered fertilizer represents 4.4% of the total energy input of the pig production system. (Abstract retrieved from CAB Abstracts by CABI’s permission