N₂O-emissions from urine and dung patches on grassland

The increasing use of mineral N fertilizers in agricultural production is regarded a major reason for enhanced N2O release from agricultural soil. But there is little information available on the effects of the application of animal excrements to the soil on the release of N2O. Grazing animals have a dominant effect on the movement of nutrients through the soil/plant/animal system and thus on the fertility of pasture soils. This is because animals use only a small proportion of the ingested nutrients, and 80-95 % of the ingested nutrients is returned to the pasture in the form of dung and urine. Excrements from grazing cattle are deposited in discrete patches comprising extremely high concentrations of total soil N. The excreta patches are enriched in these nutrients and may be regarded as hot spots of N2O emissions. The increasing use of mineral N fertilizers in agricultural production is re garded a major reason for enhanced N2O release from agricultural soil. But there is little information available on the effects of the application of animal excrements to the soil on the release of N2O. Grazing animals have a dominant effect on the movement of nutrients through the soil/plant/animal system and thus on the fertility of pasture soils.