秸秆还田对稻麦田间杂草发生的影响及化除效果

EFFECT OF RETURNING STRAW TO FIELD ON WEEDS OF RICE FIELD AND WHEAT FIELD AND THE EFFICIENCY OF CHEMICAL WEEDING

针对秸秆还田后茬田间杂草的发生及影响 ,开展了麦、稻秸秆不同还田量对直播晚稻和小麦浅耕、免耕 (覆盖 )栽培田间杂草发生的影响及化除效果的试验研究 ,结果表明 :麦秸秆还田种植水稻 ,其苗期田间杂草的发生种类以单子叶杂草 [如稗草 (Echinochloacrusgalli)、千金子 (Leptochloachinensis)等 ]为主 ,双子叶杂草[如节节草 (Commelinadiffusa) ]较少 ,随秸秆还田量的增加田间杂草有所减少 ,然而不同处理田间杂草发生无明显规律 ,说明麦秸秆不同还田量对水稻田间杂草发生无明显影响。麦秸秆全量还田水稻杂草化除效果比对照降低 15 % ;水稻秸秆全量还田 ,小麦浅免耕栽培 ,化除效果比对照下降幅度更大。改进化学除草方法 ,可提高化学除草效果 90 %～ 95 %。

The authors made experimental research on the effect of returning different amount of straw to field on occurrence of field weeds and the effect of chemical weeding. The results showed that monocotyledonous weeds such as Echinochloa crusgalli and Leptochloa chinensis were the main weeds in the rice field after returning wheat straw to field, and the dicotyledonous weeds such as Commelina diffusa were only a few. With the amount of returned wheat straw increasing, weeds in the field seemingly reduced but there was no evident law between them, or no evident effect of the amount of returned wheat straw on occurrence of field weeds. Returning all wheat straw to field made the efficiency of chemical weeding reduce by 15% as compared with CK, and returning all rice straw to field and culturing wheat in the way of shallow or zero tillage could made the efficiency reduce much more. Improving chemical weeding methods could make the efficiency increase to 90%～95%.