Fate of 15n-Labeled Organic Nitrogen in Conventionally Managed and Organic Farming Systems

Perturbation may affect N-partitioning by changing the soil's ability to transform N. This experiment investigated the extent and duration of perturbation on N-partitioning and Nmineralization in soils from two long-term systems projects at the Rodale Institute Experimental Farm, Kutztown, P A. Soils trom conventionally and organically managed systems were collected, subjected to four perturbations (none, flooding, drought, excess inorganic N), and amended with lSN-Iabeled vetch (Vicia vil/osa L.) seven weeks after the perturbation was removed. There was no difference among farm management systems based on total inorganic N measurements. l~ analysis will be conducted to determine if perturbation and farming system had a significant effect on vetch mineralization.