Effect of fertilization and weed management practices on soybean

摘要

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore during kharif 94, 95 and summer 95, 96 with a view to study the effect of fertilization and weed management practices on weed index and yield of soybean. The soil ofthe experimental field was deep clay loam in texture, classified under Typic haplustalf. In all the four seasons the experiments were laid out in the same field adopting 30 X 10 cm spacing for soybean. The experiments were laid out in a split plot design with three replication. The mainplot treatments consisted of combination of organic manures and fertilizers as indicated below "M1 - FYM 12.5 t ha~(-1) + 20:80:40 kg NPK ha~(-1), M2 - FYM 12.5 t ha~(-1) + 30:120:40 kg NPK ha~(-1), M3 - Sheep manure 6.5 t ha~(-1) + 20:80:40 kg NPK ha~(-1), M4 - Sheep manure 6.5 t ha~(-1) + 30:120:40 kg NPK ha~(-1), M5 - Bio-gas digested slurry 5.0 t ha~(-1) + 20:80:40 kg NPK ha~(-1) and M1 - Bio-gas digested slurry 5.0 t ha~(-1) + 30:120:40 kg NPK ha~(-1). The subplot treatments consisted of weed management practices as presented below : W1 -Pendimethalin 0.75 kg ha~(-1) + hand weeding (HW) at 40 days after sowing (DAS), W2 -Alachlor 1.0 kg ha~(-1) + HW at 40 DAS, W3 -Hand weeding twice on 20 and 40 DAS and W4 - Unweeded control.