Effects Of Different Fertilization Types On Paddy Soil Nitrogen Mineralization And Smbc, Smbn In Yanbian In China

The northern paddy land as an important resource occupies has an important position in the country and the world agricultural ecosystems. Study on the fertilization type which can effect on the nitrogen mineralization, the conversion processes and the number and variation of nitrogen microbial biomassas in the northern paddy land, can provide a theoretical basis and support for the soil nitrogen, carbon cycle of the farmland. In this paper, we use the PVC pipe in situ culture of continuous sampling, to measure the three types fertilizer in Yanbian in growing season the spatiotemporal dynamics of the soil nitrate nitrogen, ammonia nitrogen and the microbial biomass carbon and nitrogen, the spatial distribution pattern of the nitrogen mineralization and nitrification. Three kinds of fertilizer treatments were as follows:fertilizer (OF), fertilizer and organic manure (CF+OF), organic fertilizer (OF).The results show:1. NH4+-N content in paddy land exist obvious seasonal variation, and the upper layer of soil (0-10cm) was the highest in June; the under layer (10-20cm) was low in September and October. Administered by CF or CF+OF conducive to soil nitrogen mineralization.It is obvious that the paddy land NO3--N contents have seasonal variation, and in higher levels in September, each month paddy land inorganic nitrogen is based on the NH4--N. The three ways soil fertilization have obvious seasonal change in net nitrification rate in, The two ways soil fertilization(CF, OF) have obvious spatial differentiation in net nitrification, and stronger in August and September; Most months, the upper soil NO3--N is based on the net release, and under soil NO3-N monthly increase in the net holding.2.The upper soil organic nitrogen mineralization is seasonal variation in three types of fertilization, in June and July nitrogen mineralization is strong. In the end of growing season the nitrogen holding effect is obvious, and the soil net mineralization rate more obvious, the three way soil fertilization were significant differences (P<0.05) between the upper and under. The net nitrogen mineralization rate in CF+OF is higher than in OF single, indicating that fertilizer was applied to facilitate the nitrogen mineralization.3.The upper soil microbial biomass carbon (SMBC) has obvious spatial difference in three way soil fertilization, and the upper SMBC was significantly higher than the under. Throughout the rice growing period, the SMBC content is the highest in June.4.The upper soil microbial biomass nitrogen (SMBN) has obvious spatial difference in three way soil fertilization, and the upper SMBN was significantly higher than the under. Throughout the rice growing period, the SMBN content is the highest in July.