The Effect Of Manure And Chemical Fertilizing On Nitrogen Transformation And Functional Bacteria Diversity In Soil

In recent years long-term excessive reclamation and inappropriate management, resulting in that the farmland quality degradation in black soil area of Northeast China became a growing problem. In order to maintain the productivity of the black soil, we often apply organic fertilizer and fertilizer to the soil,but long-term application of nitrogen fertilizer will produce a series of problems.The soil nitrogen is one of the nutritive elements of crops grow, directly impacting on the soil productivity, while the cycle of nitrogen is also the most basic process of soil ecological. This paper studied the effect of soil nutrient contents and nitrogen transformation features bacteria (such as bacteria, ammonifying bacteria, nitrobacteria, denitrifying bacteria, nitrogen-fixing bacteria) by manure and chemical fertilizer; And it also analyzed the changes of the diversity of soil nitrogen transformation features bacteria—ammonia oxidizing archaea(AOA) under different fertilization treatments with PCR-DGGE sequencing method. This paper took the theoretical studies on nitrogen transformation in black soil, and provide scientific reference for the reasonable use of the nitrogen in soil and guidance for the nitrogenous fertilizer utilization in field practice and reduce the agricultural non-point source pollution.The main conclusions are shown as follow:The fertilization increased function of the bacteria associated with nitrogen transformation in soil; The correlations between soil organic matter and nitrogen transformation strain intensity were positive; The correlations between the content of total nitrogen and strength of ammonification were positive. The fertilization increased the numbers of the nitrogen transformation bacteria. And expect for the denitrifying bacteria, manure fertilizer treatments were higher than chemical fertilizer treatments; The correlations between the nitrogen transformation bacteria and the nitrogen transformation strain intensity were positive.The fertilization increased the contents of soil organic matter and total nitrogen. While the difference of the effect of manure and chemical fertilizer is significant. The contents of total nitrogen under manure treatments is significant higher than those under chemical fertilizer and manure and chemical fertilizers in equal ratio. Fertilization treatments improved the productions of crops, and the effect of manure treatments was significant; The total trends performed that high manure fertilizer>manure and chemical fertilizers in equal ratio>low manure fertilizer>high chemical fertilizer> low chemical fertilizer>CK.5The soil ammonia-oxidizing archaea(AOA) diversity index and homogeneous degrees index of high manure fertilizer are2.77and0.91, both higher than other treatments. There were consistent between DGGE analysis of the results and the conventional analysis of the conclusions. The study revealed that application of fertilizer have a little effect on the community structure of ammonia-oxidizing archaea(AOA). Cluster analysis results also showed that high similarity between manure fertilizer and CK, but lower similarity between fertilizer and CK.