Effects Of Different Fertilization Types And Cultivation Years On Nitrogen Mineralization And DOC、SON In Paddy Soil

The northern paddy soil has important research significance in the global ecological system.Study on the fertilization methods and cultivation years which can effect on the nitrogen mineralization, the number and variation of soluble organic nitrogen in the northern paddy soil, the mineralization simulation equation of first order reaction kinetics, is advantageous to the reasonable guide the scientific fertilization of paddy soil in the north, can provide a theoretical basis and support for the soil nitrogen, carbon cycle of the our country farmland, in this paper, we measured the two cultivation years and three fertilization methods in Yanbian specific areas under water-logging condition the spatiotemporal dynamics of the soil nitrate nitrogen.ammonia nitrogen and dissolved organic carbon and nitrogen-the spatial distribution pattern of the nitrogen mineralization and nitrification and mineralization simulation reaction equation. Three kinds of fertilizer treatments were as follows: chemical fertilizers (CF), chemical and organic fertilizers (COF). organic fertilizers (OF).The results show:1.NF4+-N content in paddy soil exists obvious seasonal variation during the whole period and the highest content in 70d:Three types of fertilizer paddy soil the upper soil NH4--N content is significantly higher than the lower soil:Planting around 80 paddy soil chemical and organic fertilizers (COF) processing is conducive to the soil nitrogen mineralization process.2. NO3--N content in paddy soil also exists obvious seasonal variation during the whole period and the highest content in 7d:Chemical and organic fertilizers (COF)processing significantly promote the release of NO3--N content; The strongest net nitrification in the 7d; Three fertilizer methods in around 80 paddy soil net nitrification is significantly higher than in around 120 paddy soil.3.Three fertilizer methods of paddy soil soluble organic nitrogen (SON) mineralization variation trends are similar:Mineralization process is strong in 7d; And short-term flooding enhance soil mineralization process, Long-term flooding inhibit soil mineralization process:Chemical fertilizers (CF) promote the soil soluble organic nitrogen (SON) mineralization process:Planting around 80 paddy soil soluble organic nitrogen (SON) mineralization is stronger.4.Chemical fertilizers (CF) or chemical and organic fertilizers (COF) promote to release in the upper paddy soil (0-10cm) dissolved organic carbon (DOC), and it make topsoil form the obvious vertical spatial heterogeneity of the soil:Planting around 80 paddy soil dissolved organic carbon (DOC) content was significantly higher than that of paddy soil in around 120 years.5.By the first order reaction kinetics equation of nitrogen mineralization: Planting around 80 paddy soil nitrogen mineralization potential is significantly higher than soil in around 120 years, and long-term application of organic fertilizers (OF) can increase the soil nitrogen supply ability; The accumulation of paddy soil nitrogen mineralization’of the total nitrogen, total carbon index relationship, and the significance of the upper soil is higher than the lower soil.