Studies On Optimization Soil Microenvironment With Organic Fertilizers

With the method of nylon bags and pot-cultivation in black soil, this thesis carried on the research on changes of soil character in microenvironment. It proved that organic fertilizers improve microenvironment of soil by changes of soil character in fertilizer micro-region and effects of soil in rhizosphere because of different distribution of fertilizer micro-region. The results show:Soil pH reduced after applying organic fertilizers to soil. Range of changes of pH in fertilizer micro-region is less than in non- fertilizer micro-region. This show those organic fertilizers can decompose to be amount of organic acid chemical compound, and they can move from fertilizer micro-region to non- fertilizer micro-region. And yet soil in fertilizer micro-region has buffer to change soil pH. To organic fertilizers, dynamic change of pH is not identical with different organic fertilizers.Soil structure in fertilizer micro-region is ameliorated on application organic fertilizers to soil. Content of 5-0.5mm-soil aggregate increased in fertilizer micro-region. And content of 2-0.5mm-soil aggregate increased in non- fertilizer micro-region too. Function of ameliorating on soil aggregate in fertilizer micro-region was stronger than in non- fertilizer micro-region. Content of soil micro-aggregate increased after applying to soil, and range of promotion in fertilizer micro-region is larger than in non- fertilizer micro-region.In natural condition, NCV-N moves from fertilizer micro-region to non-fertilizer micro-region. At the same time, organic fertilizer can restrain accumulation of soil NO₃-N in fertilizer micro-region. Thus content of NCV-N striking decrease in fertilizer micro-region.Application organic fertilizers increased Content of available NPK in soil. Effect on available NPK in fertilizer micro-region is larger than in non- fertilizer micro-region. In later stage, Difference of NPK content gradually decreased in fertilizer micro-region and non- fertilizer micro-region. To different organic fertilizer, corn stalk was better on P.Organic fertilizers can increase soil microbial biomass by different degree in fertilizer micro-region and non- fertilizer micro-region. But microbial biomass in fertilizer micro-region was more than in non- fertilizer micro-region. Among organic fertilizers, soil microbial biomass was rapid increased by application corn stalk. And in later stage soil microbial biomass increased too. At the same time, soil biology activity was increased by different degree too, for instance, enzyme activity (catalase, urease, invertase, cellulosase, phosphatase) was obvious increased in fertilizer micro-region.Application organic fertilizers increased soil organic matter in fertilizer micro-region, at the same time, Application organic fertilizers made soil organic matter decrease in non-fertilizer micro-region too. This show that effect on organic matter of renewing and promoting took place in fertilizer micro-region. To different organic fertilizer, application corn stalk is better.Application organic fertilizers can promote soil organo-mineral complex to form. Contents of soil whole organic carbon, carbon in heavy fraction, quantity of complex in fertilizer micro-region and in non-fertilizer micro-region increased, and Contents of soil whole organic carbon, carbon in heavy fraction, quantity of complex in fertilizer micro-region increased more than those in non-fertilizer micro-region. Of organic fertilizers, treatment of cowshit is better.Application organic fertilizers can make better forms of soil humus. Especially content of loosely combined humus. To different organic fertilizer, renewing to soilorganic matter had difference. Corn stalk and chickenshit made content of soil loosely combined humus in fertilizer micro-region, and cowshit and tree leaf made content of soil loosely combined humus in non-fertilizer micro-region. Content of HA and content of FA in fertilizer micro-region also increased.Different distribution of fertilizer micro-region has affects on...