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以黄豆、玉米、水稻这3种农业秸秆为原料,崇明东滩围垦土地为试验样区,以景观植物地肤草为目标植物,研究土壤呼吸和土壤有机碳对不同秸秆还田的响应及其可能的机制.结果表明,不同秸秆直接还田的土壤呼吸和地上植物量均高于对照组;黄豆秸秆还田后土壤呼吸相对最低,土壤有机碳最高,因此黄豆秸秆还田的土壤碳封存能力高于玉米和水稻秸秆.秸秆还田显著促进土壤微生物活性,增加了土壤微生物量以及β-糖苷酶、脱氢酶活性,脱氢酶活性与土壤呼吸相关性最显著.黄豆秸秆还田脱氢酶活性最低,相应的土壤呼吸也最低.黄豆秸秆纤维素、木质素和C/N含量最高,可降解性最低,表明黄豆秸秆难以被微生物降解利用,因而还田后其土壤微生物活性最低,最终导致最低的土壤呼吸和较高的土壤有机碳.
Taking the three types of agricultural straw such as soybean, corn and rice as raw materials and the reclaimed land of Chongming Dongtan as experimental plots, the plant Phyllostachys praecox was taken as the target plants to study the response of soil respiration and soil organic carbon to different straw returning Possible mechanism.The results showed that soil respiration and aboveground biomass of different straws returned directly to the soil were higher than that of the control group.The soil respiration of soybean straw was the lowest and soil organic carbon was the highest Higher than that of maize and rice straw. Straw returning to field significantly promoted soil microbial activity, increased soil microbial biomass and activity of β-glucosidase and dehydrogenase, and dehydrogenase activity had the most significant correlation with soil respiration. The enzyme activity was the lowest and the corresponding soil respiration was the lowest.The content of cellulose, lignin and C / N of soybean straw was the highest and the degradability was the lowest, which indicated that it was difficult for soybean straw to be degraded and utilized by microorganism, Resulting in the lowest soil respiration and higher soil organic carbon.