塔里木盆地南缘典型绿洲不同土壤类型土壤有机碳含量及矿化特征

Organic carbon and carbon mineralization characteristics under different soil types in the southern edge of Tarin Basin

以塔里木盆地南缘典型绿洲于田绿洲为靶区,通过野外取样和实验分析,研究干旱区绿洲灌漠土、棕漠土、盐土和风沙土土壤有机碳含量及矿化特征,并探究有机碳矿化能力与土壤理化性质的关系。结果表明:于田绿洲不同类型土壤总有机碳含量依次为灌漠土>棕漠土>盐土>风沙土,灌漠土和棕漠土有机碳含量随土壤剖面深度增加而减少;不同类型土壤有机碳矿化累积量具有显著差异,其中灌漠土有机碳总矿化量最高,达到0.245g·kg^(-1),风沙土最低,仅有0.145g·kg^(-1);各类型土壤有机碳矿化累积量和矿化率均随土壤剖面深度增加而减少;不同类型土壤有机碳矿化累积量与有机碳含量、全氮、速效磷、速效钾呈极显著或显著正相关,而与pH值呈显著负相关。

With field sampling and experimental analysis, we analyzed soil organic carbon and soil organic carbon mineralization in the oasis soil, and studied the correlation between soil organic carbon mineralization and soil physical and chemical properties in the northern of the Tarim Basin. The results showed that the concentration of soil organic carbon ranked in the order of irrigated desert soil 〉 brown desert soil 〉 saline soil 〉 aeolian sandy soil in Yutian Oasis, and the soil organic carbon content of irrigated desert soil and brown desert soil decreased with soil depth. The content of soil organic carbon mineralization and the rate of mineralization decreased with soil depth in different soil types. Among the 4 soil types the highest accumulative amount of CO2 - C was found released from irrigated desert soil about 0. 245g . kg-1, the lowest was aeolian sandy soil, only 0. 145g . kg-1. According to the Pearson correlation analysis results, the content of soil organic carbon was very significantly positive correlated with soil organic carbon mineralization content in different soil types. The total N, available P and available K were significantly positive and pH was significant negative correlated with it. correlated with soil organic carbon mineralization content,