Nitrogen mineralization from paddy and upland soils under flooded and nonflooded incubation

An incubation study was carried out to compare the mineralization of soil organic N under flooded conditions with that under nonflooded conditions. Soils used in this incubation were air-dried paddy soils (37 samples), air-dried upland soils (22 samples), and fresh-moist paddy soils (7 samples). The amount of mineralization of soil organic N was larger under flooded incubation than under nonflooded incubation, in all the soil samples used. The differences in the amount of N mineralized between flooded and nonflooded incubation were generally larger for air-dried paddy soil samples than for air-dried upland soil samples.