The Effect Of Conservation Tillage On Changes Of Soil Organic Carbon And The Function Mechanism

This study design four farming methods, and soil samples collected from different soil. And from the four aspects of the analysis of the results to study the protective cultivation soil organic carbon fixed aggregate influence and function mechanism. The main research results are as follows:(1) Conservation tillage affected soil aggregates itself physical properties. Conservation tillage paddy soil to major role in0-20cm soil layer, have a significant impact on the surface soil (0-5cm). Conservation tillage soil organic carbon improve the reserves, remarkably raised the large gathering of surface soil body scale, organic carbon content and humus content. Soil total organic carbon and soil aggregates scale, organic carbon content, a positive correlation between humus; With a large gathering of body scale is a significant positive correlation, and micro aggregate is a significant negative correlation humus.(2) Conservation tillage affected soil organic carbon aggregate difficult degradable properties. The conservation tillage improve0-20cm soil soil big aggregates RIc; Among them, the role played by the rice straw manuring significantly greater than no-tillage. Soil aggregate RIc and soil total organic carbon was positively related to the same amount, but not significant.(3)Conservation tillage on soil organic carbon mineralization and metal oxidation effect is remarkable. Rice straw manuring improve the0-20cm macro aggregate mineralization content and Fe/Al-SOC content, Ca-SOC content. Among them, no-tillage was dominant. No-tillage also reduced the5-20cm soil mineralization content, improving the Fe/Al-SOC and Ca-SOC content of2-0.25mm and<0.054mm aggregate in0-5cm soil layer.Soil total mineralization and Fe/Al-SOC, Ca-SOC positively related content,and in>2mm aggregate level is a significant positive correlation. Soil total mineralization, Fe/Al-SOC content, Ca-SOC organic carbon content and total positive correlation between each other.(4) Conservation tillage soil body fungi to reunite biomass significant effects. Conservation tillage mainly improve the0-20cm soil aggregates’ fungi biomass, including no-tillage improved the0-5cm soil layer macro aggregate fungi biomass. Rice straw manuring improved the0-5cm soil layer soil micro aggregate fungi biomass. At the same time, macro aggregate fungi biomass is also significantly higher micro aggregate. Micro aggregate fungi biomass and soil organic carbon amount is the significant negative correlation, and soil aggregates mineralization content negative correlation.