ABSTRACT

Reducing the water loss sources, i.e. soil evaporation and weeds presence, is an essential act for keeping well soil moisture to crop growth, especially under drought conditions. Therefore, two–year field trials were conducted for seeking the best compatible practice between irrigation regime and weed control method in onion onion. Three irrigation water regimes (60%, 80% and 100% of the crop water requirements, CWR) and seven weed control practices (rice, wheat and peanut straws as soil mulches as well as oxadiargyl, oxyfluorfen, weeding, and unweeded) were applied. Findings revealed that the application of 60% of CWR either with peanut straw mulch or weeding recorded the maximum reduction in weed biomass. In plots mulched by peanut straw irrigation with 80% of CWR produced acceptable marketable bulb yield, NPK contents, flavonoids content and economic returns closing irrigation by 100% of CWR. In conclusion, the rate of water loss from soil surface through evaporation was much lower in case of mulch treatment than non–mulched one. Thus, mulch not only keeps weeds out but also maintains soil moisture. This allows the opportunity to reduce irrigation water by 20% (80% of CWR) with gaining acceptable yield, saving water and raising benefit/cost ratio.

摘要

减少水分流失源，即土壤蒸发和杂草的存在，是保持土壤水分对作物生长至关重要的行为，尤其是在干旱条件下。因此，进行了为期两年的田间试验，以寻求洋葱灌溉制度和杂草控制方法之间的最佳兼容实践。应用了三种灌溉用水方式（作物需水量的 60%、80% 和 100%，CWR）和七种杂草控制措施（稻草、小麦和花生秸秆作为土壤覆盖物以及恶二灵、乙氧氟草醚、除草和未除草） . 调查结果表明，60% 的 CWR 与花生秸秆覆盖或除草一起使用记录了杂草生物量的最大减少。在用 80% 的 CWR 覆盖花生秸秆灌溉的地块中，产生了可接受的可销售鳞茎产量、NPK 含量、黄酮类化合物含量和经济效益关闭灌溉 100% 的 CWR。总之，在覆盖处理的情况下，通过蒸发从土壤表面流失的水分速率比不覆盖处理的要低得多。因此，覆盖物不仅可以防止杂草进入，还可以保持土壤水分。这样就有机会将灌溉用水减少 20%（CWR 的 80%），同时获得可接受的产量、节水并提高效益/成本比。