Weed and Nitrogen Management Effects on Weed Infestation and Crop Productivity of Wheat-Mungbean Sequence in Conventional and Conservation Tillage Practices

摘要

Weeds appear as a challenge in conservation agriculture, and hence, weed management is of paramount importance. The nitrogen (N) management under changing tillage scenarios is another important dimension of research. Therefore, a field experiment waslaid out in a split-plot design with six tillage, residue and N management options in main plots and four weed control practices in subplots. The results showed that the zero tillage (ZT) + residue (R) + 75 of required N + rest N based on GreenSeeker~(TM) (GS) and sequential application of pendimethalin followed by sulphosul-phuron alone and in combination resulted in significant reductions in weed dry weight and caused a considerable increase in weed control efficiency and weed control index in wheat.Their carry-over effect was also significant on the reduction in weed growth in mungbean. Residue retention in ZT gave 5.5 and 6.1 higher wheat grain yield in 2013-2014 and 2014-2015, respectively, than the residue incorporation, whereas in mungbean the increment was to the extent of 8.4 and 7.8. Zero tilled plots recorded 25.5 and 42.8 higher water productivity (for wheat) and mungbean productivity. Highest net energy returns were observed in ZT + R + 75N + GS in wheat in both the years. The treatment ZT + R + 75N + GS also fetched higher gross and net returns in wheat and mungbean. In all cases, herbicides with sequential application proved better than one-time ready-mix application.