养殖废水灌溉对玉米地土壤水溶性碳及其剖面分布的影响

Influence of Irrigation with Dairy Effluent on Soil Dissolved Organic Carbon and Its Distribution of the Section in the Corn Field

为了研究养殖废水灌溉对土壤水溶性碳量及其占总有机碳量比例的剖面分布的影响,设置水质和灌溉量处理,测定了玉米地土壤总有机碳和水溶性碳量,分析了水溶性碳占总有机碳比例及其剖面分布特征。结果表明,总有机碳及水溶性碳量在土壤表层较高,且随着土层加深均有所减少。养殖废水灌溉条件下的土壤总有机碳和水溶性碳量总体上比清水灌溉处理的高,这说明在一定范围内养殖废水灌溉更有利于土壤中有机碳量的增加。清水灌溉条件下,灌水量为640 m^3/hm^2时土壤总有机碳量最高;灌水量为760 m^3/hm^2时水溶性碳量最高。养殖废水灌溉条件下,灌水量为880 m^3/hm^2时土壤总有机碳和水溶性碳量均为最高。由于土壤中的总有机碳在土壤深层分布较少,且随土层加深土壤总有机碳量下降幅度减小,水溶性碳占总有机碳的比例随土层深度加深而逐步增加。养殖废水灌溉有利于土壤总有机碳、水溶性碳量的增加,并可促进二者在土壤表层的积累。

Aiming to analyze the effect of livestocks waste water irrigation on soil total organic carbon, dissolved organic carbon and the proportion of them, lysimeter experiment was conducted including clear water irrigation and livestocks waste water irrigation with three irrigation amounts. The results showed that the contents of total organic carbon and dissolved organic carbon decreased with the increase of soil depth. Generally, the contents of the total organic carbon irrigated by livestocks waste water were higher than those under clear water irrigation, which showed that livestocks waste water irrigation would induce the increase of soil carbon content within a cer- tain range, especially in upper soil. The proportion of dissolved organic carbon to the total organic carbon gradual- ly increased with soil depth, as the decrement of soil total organic carbon increased with soil depth and decrement of soluble organic carbon decreased. Under the clear water irrigation, the content of total organic carbon in the surface soil was the highest when the irrigation amount was 640 m3/hm： and the content of dissolved organic car- bon was the highest when the irrigation amount was 760 m3/hm2; under the livestocks waste water irrigation, both total organic carbon and dissolved organic carbon contents were the highest when the irrigation amount was 880 m3/hm2. Livestocks waste water irrigation is beneficial to the increase of the contents of soil total organic carbon and dissolved organic carbon and the accumulation of them in the upper soil.