持续棉秆还田对新疆棉田土壤可矿化碳库的影响

发布时间：2018-08-21 08:15

【摘要】：依据新疆绿洲棉花长期连作的微区定位试验,研究了在秸秆还田和不还田处理下,棉田土壤有机碳矿化特征,以及土壤有机碳释放随棉花秸秆还田年限的变化规律。结果表明:秸秆还田与不还田处理相比增加了0~60 cm土层土壤的总有机碳(TOC)、可矿化碳(MC)的含量和矿化速率(MR),并且随着秸秆还田年限的加长呈上升趋势,但随土层的加深而下降。持续秸秆还田后棉田随着秸秆还田时间增加土壤有机碳矿化速率、累积矿化排放量(CO_2-C排放量)增加,但矿化强度呈降低趋势,而棉花连作但秸秆不还田的棉田变化趋势与之相反。说明棉花秸秆还田措施增加了新疆绿洲棉田土壤有机碳含量,土壤中有机碳虽然不断得到补充,但尚未达到饱和状态,随着秸秆还田时间延长棉田固碳能力下降。
[Abstract]:Based on the microregional localization experiment of cotton continuous cropping in oasis of Xinjiang for a long time, the mineralization characteristics of soil organic carbon in cotton field and the change of soil organic carbon release with the returning years of cotton straw were studied under straw returning and non-returning treatment. The results showed that the content of total organic carbon (TOC),) mineralizable carbon (MC) and the mineralization rate (MR),) of total organic carbon (TOC),) in the soil layer of 0 ~ 60 cm soil layer were increased compared with the non-return treatment. The content of (MC) and the mineralization rate of the total organic carbon mineralizable carbon (MC) in the soil layer increased with the increase of the number of years of straw returning to the field. After continuous straw returning to the field, the soil organic carbon mineralization rate increased, and the cumulative mineralization discharge (CO_2-C emission) increased, but the mineralization intensity decreased with the straw returning time, and the soil organic carbon mineralization rate increased with the straw returning time, but the mineralization intensity decreased with the increase of soil organic carbon mineralization rate. The change trend of cotton field with continuous cropping but no straw returning to the field was opposite to that of cotton field. The results showed that the measures of returning cotton straw to field increased soil organic carbon content in Xinjiang oasis cotton field. Although soil organic carbon was continuously supplemented, it was not yet saturated, and the carbon sequestration capacity of cotton field decreased with the extension of straw returning time.
【作者单位】：石河子大学新疆兵团绿洲生态农业重点实验室;克拉玛依市克拉玛依区农林水牧局;
【基金】：国家自然科学基金项目(31260307)资助
【分类号】：S153.6

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