Nitrogen Mineralization Processes of Sediments and Soil under Continuously Waterlogged Incubation Conditions

Under waterlogged incubation conditions,the nitrogen mineralization of two different sediments(HH and HK)and a general soil(TR) were investigated with the method of the continuous incubation.The results indicated that the mineralization trend was basically uniform.The N mineralization quantity increased promptly to its peak value after 11 incubation days,and then derceased gradually to the initiative levels.The peak of nitrogen mineralization of HH and HK sediments appeared earlier than that of TR.The peak of ammonium in the N mineralzation process of HH and HK appeared after 4 days of incubation,but the TR occurred after 7 day.The contents of organic matter,the total nitrogen and the fixed ammonium during the process of incubation were declineing.It indicated that the aminate microorganisms were replaced by others,and the microbe propagated largely.Then the microbial immobilization function was gradually stronger than N mineralization,as a result of the quantity of the mineralization N and the fixed ammonium was declining promptly.