In order to eva1uate the weed contro1 efficiency of corn straw residue mu1ching and the effects on rice yie1d and the reduction in herbicide app1ication (80%Bensu1furon-methy1·Mefenacet WP) in paddy fie1d, weed a-mount, growth and yie1d of rice were investigated. The resu1ts showed that corn straw residue mu1ching cou1d reduce the number and fresh weight of weeds in paddy fie1d significant1y, and the effects increased with the mu1ching amount. Com-pared to the CK (without mu1ching and herbicide), the contro1 efficiency of 5 400-7 200 kg/hm2 corn straw residue mu1ching on weeds, such as Leptochloa chinensis ( L. ) Nees, Echinochloa crusgalli ( L. ) Beauv, Cyperus difformis L. , Ammannia baccifera L. and Monochoria vaginalis ( Burm. f. ) Pres1, were above 80% 45-d after mu1ching. Furthermore, herbicide and straw mu1ching were synergistic to weeds, 3 600-7 200 kg/hm2 corn straw residue mu1ching combining 240 g/hm2 80% Bensu1furon-methy1 · Mefenacet WP, which is ha1f recommended dosage, contro11ing 90%-100% of the above weeds in 45 d and enhancing the rice yie1d. Significant positive corre1ations were presented between herbicide dosage, corn-residue mu1ching amount and weed contro1 efficacy and rice yie1d. There-fore, corn straw residue mu1ching cou1d contribute to reducing herbicide dosage and enhancing rice yie1d.%为明确玉米秸秆不同覆盖还田量对水稻田杂草的控制作用和对水稻产量的影响以及秸秆覆盖还田对化学除草剂减量使用的可行性,通过田间小区试验研究了玉米秸秆覆盖还田结合化学除草剂(80%苄嘧·苯噻酰草胺WP)对水稻田杂草的控制效果以及对水稻产量的影响。结果表明玉米秸秆覆盖还田对水稻田杂草具有较好的控制效果,随着秸秆覆盖还田量的增加,杂草控制效果明显上升,5400~7200 kg/hm2秸秆覆盖还田45 d内对水稻田稗草、千金子、莎草、水苋菜、鸭舌草的控制效果达80%以上。而且化学除草剂使用与玉米秸秆覆盖还田措施对水稻田杂草具有协同控草作用,施药后45 d 3600~7200 kg/hm2秸秆覆盖还田结合240 g/hm2(常规使用剂量的50%)化学除草剂对水稻田杂草总体控制效果达90%~100%,且对水稻产量提高也具有明显的促进作用。药后45 d杂草株防效和小区水稻产量与除草剂剂量、秸秆覆盖还田量之间均存在显著正相关。因此玉米秸秆覆盖还田显著降低了化学除草剂的使用量,有助于提高玉米秸秆利用效率。
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