Nitrogen and weed management effects on soybean (Glycine max L.) yield in Kandahar, Afghanistan

Abstract

Soybean [Glycine max (L.)] ranks fourth among the most important crops in the world, following maize (1017 Mt), wheat (713 Mt) and rice (741 Mt). In 2014, soybean was grown in an area of about 111 M ha worldwide. The global production of soybean has shown a rising trend over the years (79 Mt in 1983, 115 Mt in 1993, 191 Mt in 2003, and 276 Mt in 2013). To assess the impact of weed and N management on soybean growth and productivity, a field experiment was carried out in a split-plot design with three replications during the spring season of 2020-21 at the Afghanistan National Agricultural Science and Technology University (ANASTU), Kandahar, Afghanistan. The main plot treatments consisted of three weed management options, namely weedy check, pendimethalin 1 kg/ha at 1-2 DAS followed by 1 hand weeding at 25 DAS and pendimethalin 1 kg/ha at 1-2 DAS followed by Imazethapyr 100 g/ha at 25 DAS. The sub-plot treatments included four N levels (~0, 40, 60 and 80 kg N/ha, i.e., N0, N40, N60 and N80). Weed and N management had significant effects on all the growth parameters, yield attributes and yield of soybean. The highest values of plant height, leaf area index, DMA per plant, grain yield, Stover yield, biological yield and harvest index were recorded with the application of pendimethalin fb imazethapyr with 80 kg N/ha. Therefore, it is suggested that pendimethalin fb imazethapyr with 80 kg N/ha should be applied for effective weed control and higher soybean production and income in Kandahar, Afghanistan.