不同耕作措施对(土娄)土土壤有机碳形态及活性的影响

Effect of different cultivation measures on activity and bound forms of organic carbon in Lou Soil

为了探明不同耕作措施对土壤有机碳形态和活性的影响,以关中地区小麦、玉米轮作条件下,历时7 a不同耕作方式(深松、旋耕、免耕、传统耕作)的定位试验为研究对象,测定了不同土层土壤的总有机碳,高、中活性有机碳含量以及松结态、稳结态、紧接态有机碳含量,并计算了松结态有机碳与紧结态有机碳的比值(松/紧)。结果表明,与传统耕作比较,在小麦秸秆高留茬情况下,无论玉米秸秆是否还田,旋耕、深松和免耕处理均既能提高土壤有机碳含量,又能提高土壤的活性有机碳和松结态有机碳含量,并提高松结态有机碳与紧结态有机碳的比值,而深松和旋耕的效果比免耕明显,是关中地区比较理想的耕作模式。

In order to study the effect of different cultivation measures on activity and bound forms of organic carbon,a seven years＇location experiment of different tillage modes（sub-soiling,rotary tillage,no-tillage and conventional tillage ） in the condition of wheat-corn rotation in Lou soil in Guanzhong plain was conducted.The content of total soil organic carbon,highly labile organic carbon, mid-labile organic carbon,loosely combined organic carbon,stably combined organic carbon and tightly combined organic carbon in different soil layers were analysed.The ratios of loosely to tightly combined organic carbon was also calculated.The results showed that compared to the conventional tillage,rotary tillage,sub-soiling and no-tillage all increased the content of soil organic carbon,loosely combined organic carbon,labile organic carbon and the ratios of loosely to tightly combined organic carbon in the condition of high wheat stubble mulching,no matter with corn stubble mulching or without.The comparison between several cultivation measures indicated that the effects of rotary tillage and sub-soiling were more significant than no-tillage.So we can draw the conclusion that rotary tillage and sub-soiling are the ideal tillage measures in Guanzhong plain.