Effects Of Black Soil Long-term Test Undisturbed Soil Moved On Soil Microorganisms

The northeast black soil have fertile soil property, Loose texture, and abundant organic matter,but the fertility declining in recent years. Long-term experiments have important significances in the study of soil fertility, environmental evolution, crop yields and so on, deeply domestic and international attention.China began to build the long-term experiment of soil fertilizer from the early 1980 s, but due to the speeding up of urbanization, some long-term experiments facing the situation of destroyed or moved. Soil microorganisms are very sensitive to their living microenvironment, May be affected by farming methods, vegetation types, soil fertility and so on.In this study, we examined the changes in soil microbial biomass content, soil enzyme activity and soil microbial community structure in two soil layers(0-20 cm, 20-40 cm) with four treatments(CK, NPK, M, MNPK) in the before and after the black soil long-term test undisturbed soil moving,discuss the influences of the mowe on soil microbial properties. The main research harvests are as follows:(1)Comparing the changes of three categories of microorganism amount, microbial biomass C,N content and four kinds of soil enzyme activity in five years before and after the move, found that interannual changes of the microbial indicators were not large, the microbial indicators of after moving 2011 and 2012 were relatively high, and the microbial indicators of before moving2010 and after moving 3013 as wheat stubble were similar.( 2) All the samples of the before and after the move had the similarities in the bacterial DGGE profiles, while there some changes in the number and brightness of fungi DGGE bands among all the samples of the before and after the move(3)On cluster analysis of the DGGE profiles, the changes in bacterial community structure of each treatment were not large between the before and after the move, while fungal community structure had a part of changes, the changes in fungal community structure of MNPK treatment were more significant between the before and after the move.(4)On principal component analysis of the DGGE profiles, in 0 ~ 20 cm soil layer, bacterial and fungal community structure of each treatment produce differentiations between the before and after the move, but the distribution law of treatments were consistent in two years, in 20 ~ 40 cm soil layer, the distribution law of bacterial community structure of MNPK and NPK treatments changed between the before and after the move, and the distribution law of fungal community structure of MNPK and CK treatments changed too.(5)The results of DGGE bands sequencing showed that, Proteobacteria(δ- and γ-) and Actinobacteria were the dominant populations of bacteria in farmland black soil, Ascomycota and Basidiomycota were the dominant populations of fungus in farmland black soil, and them were stable presence.Based on the above results show that, the disturbance influences of the moving on soil microorganism were far less than the influences of farming methods, vegetation types, soil fertility and so on.