Abstract

Weed infestation is a major factor attributed for the poor yield of soybean. Field experiments were therefore conducted to evaluate the influence of row spacing and weed control methods on weed dynamics, seed yield and profitability of soybean. The use of 50 cm row spacing reduced the density and biomass of grass weed species including Digitaria horizontalis, Panicum maximum, Cynodon dactylon and Paspalum scrobiculatum with subsequently higher soybean dry matter, seed yield, revenue and marginal returns compared to 75 and 100 cm row spacing. However, some broad-leaved weed species like Commelina benghalensis, Gomphrena celosioides and Amaranthus spinosus were not controlled at 50 compared to 75 and 100 cm row spacing. Regardless of row spacing, herbicide (butachlor) application plus hoe weeding reduced total weed density and biomass with subsequently higher soybean dry matter, seed yield, revenue and marginal returns than two hoe weedings or sole herbicide application. The result suggests that narrow row spacing of 50 cm and integrated weed control by butachlor plus hoe weeding will improve weed control efficiency, productivity and profitability of soybean.

摘要

杂草侵扰是大豆产量低的一个主要因素。因此进行田间试验以评估行距和杂草控制方法对大豆杂草动态、种子产量和盈利能力的影响。与 75 厘米和 100 厘米的行距相比，使用 50 厘米的行距降低了禾本科杂草物种的密度和生物量，包括横木、大麦、狗牙根和雀稗，随后大豆干物质、种子产量、收入和边际收益更高. 然而，一些阔叶杂草，如Commelina benghalensis、Gomphrena celosioides和Amaranthus spinosus与 75 厘米和 100 厘米的行距相比，没有控制在 50 厘米。无论行距如何，除草剂（丁草胺）施用加锄草除草降低了总杂草密度和生物量，随后大豆干物质、种子产量、收入和边际回报高于两种锄草除草或单独施用除草剂。结果表明，50 cm的窄行距和丁草胺+锄草联合除草将提高大豆的除草效率、生产力和盈利能力。