耕作方式对滨海盐渍土有机碳含量及团聚体特性的影响

为探明不同耕作措施对滨海盐渍土耕层土壤有机碳含量和团聚体特征的影响,本研究在江苏省东台市滨海滩涂农田区开展田间试验,选择玉米-大麦的旱-旱轮作方式,采用传统翻耕、深翻、少耕和免耕4种耕作方式,分别对耕层土壤的有机碳含量、土壤体积质量(容重)、水稳性团聚体含量和稳定性进行测定。结果表明:与传统翻耕相比,免耕措施利于促进土壤有机碳的积累,免耕能使土壤有机碳含量增加18%~32%;少、免耕措施能使0~10 cm土层0.25 mm团聚体增加10%~31%,并且能显著增加0~20 cm土层土壤平均重量直径和几何平均直径值;团聚体中有机碳含量表现为,除0.25~0.5 mm团聚体外,在5 mm至0.5~1 mm粒径之间,粒径愈小,有机碳含量愈高。

Effects of Tillage on Soil Organic Carbon and Stability of Soil Aggregates in Costal Saline Soil Region

The effects of different tillage systems on the contents of soil organic carbon and aggregates properties were studied. A field experiment was conducted at costal saline soil region, Dong tai City, Jiangsu Province. four tillage systems were adopted: conventional tillage (CT), deep tillage (DT), minimum tillage (MT) and no tillage (NT), soil organic carbon, soil bulk density and water-stable aggregates were measured. The results showed that, Compared with CT, NT tended to enhance organic carbon contents,the range was 18%~32%. Water-state macro-aggregates content of MT and NT was higher than other treatments 10%~31%, the MWD and GMD value at 0-20 cm soil layer of MT and NT was significantly improved. Under different tillage systems, the content of SOC in different size groups were share the same pattern, between the >5 mm and 0.5~1 mm, the SOC concentration was increased along with the size decreased, but the concentration was decreases at 0.25~0.5 mm.