不同播期对杂草抑制及农药残留的研究(英文)

[目的]有效抑制农田杂草,使土壤中农药残留降解,生产无公害农产品是非常重要的方面。[方法]对于高残留农药长期使用的地区,采用连续2～3年秋收浅耕、翌年春播时早浅耕、晚播种或直接晚耕播种3种措施,研究杂草的抑制效果。通过取样测量作物幼根长和鲜重,分析这3种措施对土壤残留农药的削减程度。[结果]氟乐灵在黄芪田长期使用时,土壤残留农药抑制下茬苜蓿幼根生长,幼根较对照株缩短2.1～2.9 cm/株,鲜重量减少0.19～0.20g/株;甲磺隆在苜蓿田长期使用时,下茬黄芪幼根较对照株缩短1.9～2.0 cm/株,鲜重量减少0.13～0.15 g/株;秋收后及时浅耕可将落入地表的杂草种子全耙入0～10 cm耕层内;翌年春播早浅耕可诱发土壤表层的杂草种子提前萌发出苗,10 d后耕种,能防除40%左右的杂草株数;较正常播种期推迟10 d后直接晚耕播种,可防除30%左右杂草株数;苗期或后期拔(捋)出残余杂草种子时,除草效果理想,对下茬作物幼苗生长发育及产量无任何不良影响。[结论]在长残效农药长期使用地区进行2～3年秋收浅耕及不同耕播期加人工锄草,能有效控制农田杂草的危害,不污染农田土壤和生活环境,且加速对土壤残留农药的降解。

Effects of Different Sowing Dates on Weed Suppression and Pesticide Residue in Soil

Objective] To effectively suppress weeds and degrade pesticide residues in soil, pol ution-free agricultural production is a very important way. [Method] In re-gions where high residual pesticides had been applied for a long term, 2-3 consec-utive years of shal ow ploughing after the autumn harvest, early shal ow ploughing and sowing later in the next spring, and late ploughing and sowing were conducted, and the effects of the three measures on weed suppression and reduction of pesti-cide residue in soil were analyzed by measuring the length and fresh weight of crop radicles. [Result] Trifluralin applied in the A. membranaceus field for a long term limited the growth of the alfalfa seedlings. That is, the radicle length of each plant was 2.1-2.9 cm shorter than that of the control, and the fresh weight of each plant reduced by 0.19-0.20 g. Metsulfuron methyl applied in the alfalfa field for a long term also limited the growth of the alfalfa seedlings, that is, the radicle length of each plant was 1.9-2.0 cm shorter than that of the control, and the fresh weight of each plant reduced by 0.13-0.15 g. Shal ow ploughing was conducted within two days after the autumn harvest, and al weed seeds on the ground were plowed into the plough layer 0-10 cm instead of deep soil. Early shal ow ploughing in the next spring could make most seeds of weeds in surface soil sprout early, and sowing was conducted after 10 d, so that about 40% of weeds sprouting early were kil ed off. However, after shal ow ploughing and sowing were conducted 10 d later than the normal sowing period, and around 30% of weeds were kil ed off. In addition, the weeds left in soil should be removed manual y at the seedling stage or in late period. These measures had no adverse impact on the growth and development of crop radicles and yield. [Conclusion] In regions where pesticides with long-term residue had been applied for a long term, 2-3 consecutive years of shal ow plough-ing after the autumn harvest, different farming and sowing measures and artificial weeding could suppress weeds in the crop fields effectively, did not pol ute soil en-vironment, and promoted the degradation of pesticides left in soil.