玉米秸秆深翻还田对土壤及其团聚体内有机碳含量和化学组成的影响OA北大核心CSTPCD

Through field experiments,the effects of deep plowing of maize straw into the field on the surface(0-20 cm)and sub-surface(20-40 cm)soil and the organic carbon content and chemical composition of soil aggregates were studied.The results showed that,in both surface and subsurface soils,compared with the control treatment without returning maize straw,the proportion of>2 mm water-stable macroaggregates significantly increased after straw deep plowing and returning,while the proportion of water-stable micro-aggregates of 0.25-0.053 mm decreased significantly,making the mean weight diameter of the water-stable aggregates significantly increased.The content of or-ganic carbon,particulate organic carbon,humic acid carbon and humin carbon in soil,and the ratio of humic acid carbon to fulvic acid carbon were significantly increased,and the water-soluble or-ganic carbon content also showed an increasing trend;in the water-stable aggregates of different sizes,the content of organic carbon,water-soluble organic carbon and humus carbon also increased significantly or showed an increasing trend;from the chemical composition of soil organic carbon,in the>2 mm water-stable macroaggregates of soil,the alkyl carbon tended to decrease and the o-alkyl carbon tended to increase,so that the ratio of alkyl carbon to o-alkyl carbon tended to de-crease.The above results indicate that maize straw returning with deep plowing can not only increase the organic carbon content of surface and subsurface soil,but also help improve soil humification and soil structure.Therefore,it is an effective measure to improve soil carbon sequestration capacity and fertility quality.