Effects Of Different Conservation Tillage Methods On Population And Diversity Of Soil Microorganism

On basis of the principles of soil microbiology and pedology, an experiment was conducted to compare the effects of conventional tillage (T) and three conservation tillage practices on population, diversity and functional groups of soil microorganism of pea field and wheat field in semi-arid areas of the Loess Plateau. The three conservational tillage practices included conventional tillage with straw incorporated (TS), no-till with no straw cover (NT), no-till with stubble retention (NTS). The main research results are as the follows:1. Population of soil fungi was affected by the various tillage treatments to different extent as the follows.(1)Treatments of no-till resulted in greater population of soil fungi than the conventional tillage, which was not influenced by the changes of season and cultivable mode. The conventional tillage covered with straw further significantly increased soil fungi quantity.(2)Total quantity of soil fungi the pea field was consistently higher than the wheat field in all the tillage treatments.(3)The pea field:soil fungi total quantities of the three conservation tillage treatments were significantly higher than the T treatment, in which the effect of NTS reached the extremely remarkable evel.(4)The influence of the different conservation tillage varied on soil fungi population with seasonal changes. Before sowing, soil fungi population significantly existed stratification among the various layers of soil profile. After harvesting, however, the upper formation and the lower level height do not decide actually, appears the crest value in turn.2. Under conditions of this experiment, superiority community resulting from treatments of straw incorporated, no-till with no straw cover, and the cultivable mode was the major factor for influencing on soil fungi composition.(1)In treatment of No-till with stubble retention, soil fungi community structure multiple Simpson (J) index, though not very obvious, could be ranged as NTS >TS and NT>CT, which involved with factors such as cultivable mode, straw covering, season changes and soil depths. Shannon (H) index were remarkable affected by no-till with no straw cover.(2)As far as the pea field concerned , all the three conservation tillage methods resulted in better uniformity of soil fungi community in comparison with the traditional cultivation.(3)In comparison to no-till without stubble treatment, conventional tillage with straw incorporated attributed soil fungi community structure multiple Simpson (J) index were T