不同复种制下秸秆还田对水稻生产能力的影响

Effect of straw returning to field on rice productivity in different cropping systems

对3种复种制度(稻–稻–肥(紫云英)、稻–稻–油(油菜)、稻–稻–闲(冬闲))下秸秆还田对水稻生产能力的影响进行研究。结果表明:冬作秸秆还田条件下,早稻产量以稻–稻–肥处理最高,稻–稻–油处理居中,两者分别比稻–稻–闲处理高3.1%和1.8%;冬作秸秆与早稻秸秆还田使晚稻显著增产,稻–稻–肥与稻–稻–油处理比稻–稻–闲处理分别增产15.4%和11.0%;秸秆还田使水稻增产的主要原因是显著提高了叶面积、干物质积累量、有效穗数、每穗粒数和粒叶比,不同冬作秸秆还田的增产效应有差异,绿肥(紫云英)效果好于油菜秸秆,且2种秸秆对增加早稻干物质积累的作用机制具有明显差异,绿肥主要增加孕穗前的干物质积累,而油菜秸秆主要增加齐穗后的干物质积累。

Effect of straw returning to field on productivity of rice has been studied in three cropping systems, rice-rice-green manure, rice-rice-rapeseed and rice-rice-fallow. The main results show that under the condition of winter crop straw returning to field, yield of early rice in rice-rice-green manure system is the highest, and that in rice-rice-rapeseed is next to it, both of them are higher than that in rice-rice-fallow system by 3.1% and 1.8% respectively. The winter crop and early rice straw returning to field have increased the yield of late rice significantly, the output of late rice in rice-rice-green manure system and the output in rice-rice-rapeseed system are higher than that in rice-rice-fallow system by 15.4% and 11% respectively. The main reasons of rice yield increase are the straw returning to the field helps to expand the leaf area, improve the dry matter accumulation, effective panicles, grain number per panicle and ratio of grain number to leaf area. The differences in yield increasement by straw returning have been observed between different winter crops＇ straw. Dry matter accumulation of rice has been improved by straw returning, while there exists clear difference in early rice dry matter increasing functional mechanism between two types of straw, green manure mainly helps to increase dry matter accumulation before booting stage, while rapeseed straw mainly operate after heading stage.