Effects of Different Fertilization Practices on Nitrogen Mineralization of Paddy Soils

Paddy soils from different fertilization treatments in the field experiment were collected to study the effects of different fertilization practices on soil nitrogen mineralization by using water-logged incubation method.The results showed that compared with control(no chemical nitrogen application),soil nitrogen mineralization capacity was promoted by either application of chemical nitrogen fertilizer or organic fertilizer.New fertilization practices which included applying the mixture of lignin and nitrogen fertilizer,slow-release fertilizer specific for rice,the mixture of organic carbon compounds and nitrogen fertilizer decreased the capacity of soil nitrogen mineralization.The application of the mixture of organic carbon compounds and nitrogen fertilizer reduced the amount of mineralized nitrogen by 18.5% during the water-logged incubation,while the total nitrogen of soil was increased by 16.7% compared with the treatment of local nitrogen application.These results suggest that the new fertilization practices are beneficial to increase nitrogen immobilization in the paddy soils thus can reduce the risk of nitrogen loss to the environment.