南方不同“冬种+双季稻”种植模式对土壤有机碳和作物产量的影响

设置了冬闲-双季稻、紫云英-双季稻、油菜-双季稻、大蒜-双季稻,马铃薯、紫云英、油菜轮作接茬双季稻5个处理,通过3年(2013—2015)大田试验,系统研究了双季稻田冬季复种对产量和土壤有机碳、活性有机碳及碳库管理指数等的影响。结果表明:冬种作物早稻产量均高于对照,晚稻产量除冬种油菜有所降低外,其他各冬作处理均高于对照。各冬种处理土壤总有机碳、活性有机碳、可溶性有机碳、微生物量碳含量和碳库指数较冬闲处理均有显著提高。土壤碳库管理指数除了冬季作物轮种处理外,其他冬种处理较冬闲处理均有显著提高。土壤总有机碳与活性有机碳和微生物量碳之间呈极显著相关,与可溶性有机碳和碳库管理指数存在显著相关,碳库活度和碳库活度指数各冬种处理也有所提高,但影响不显著。

Effects of multiple winter cropping on soil organic carbon and double-cropping rice yield in the south of China

The study included a set of five treatments:winter fallow-double cropping rice; milk vetch-double cropping rice; rape-double cropping rice; garlic-double cropping rice; and potato, milk vetch, and rape rotation-double cropping rice. The effects of multiple winter-cropping on the early-and late-rice yields, soil organic carbon, active organic carbon, and carbon library management index in double cropping rice field were studied for a period of three years (2013-2015). The early-rice yields of winter-crop treatments were higher than that of the control treatment. The late-rice yields of the winter treatments were also higher than that of the control; however, the late-rice yield of winter rape was lower than that of the control. The total organic carbon, active organic carbon, soluble organic carbon, microbial biomass carbon content, and carbon library index of the winter treatment were extensively improved. In addition to the winter crop rotation, the soil-carbon library management indices of the other winter treatments were significantly improved. A significant correlation was observed between the total organic carbon and active organic carbon, microbial biomass of soil, total organic carbon with the soluble organic carbon, and the carbon library management index. The carbon storage activity and carbon-storage activity index were also improved, but the effects were not significant.