Long term effect of legume intensified crop rotations and tillage practices on productivity and profitability of maize vis-a-vis soil fertility in North-Western Indo-Gangetic Plains of India

The present study was planned to evaluate the long term effect of legume intensified maize based crop rotations and tillage practices on productivity, profitability of maize vis-a-vis soil health. The experiment consisted of three tillage practices i.e. zero tillage (ZT), permanent bed (PB) and conventional tillage (CT) as main plot treatments and four crop rotations (MWMb; maize-wheat-mungbean, MCS; maize-chickpea-Sesbania, MMuMb; maize-mustard-mungbean, MMS; maizemaize-Sesbania) as sub plot treatments. Results revealed that ZT and PB resulted into significantly (P<0.05) improvement in grain (7.7-14.2%) and stover yield (7.4-13.0%) of maize over CT. Similarly, maize grain and stover yield were invariably higher in MCS and MWMb systems compared to MMuMb and MMS rotations. The total soil carbon (TSC) content increased by 15.4-17.4 and 20.32-20.91% with ZT and PB over CT in 0-15 and 15-30 cm soil depths, respectively. However, MCS and MWMb rotations registered 41.3-18.0% (0-15 cm) and 8.4-11.0% (15-30 cm) higher TSC over MMuMb rotation. Similarly, ZT and PB resulted into significantly (P<0.05) improvement in available soil nitrogen (N), phosphorus (P) and potassium (K) compared to CT. ZT/PB under MCS crop rotations registered higher net returns and BC ratio compared to rest of the treatment combinations. Interaction effect of tillage and crop rotations were significant (P<0.05) for stover yield, net returns, BC ratio and TSC and all these parameters were reported maximum with ZT-MCS. Thus, the present study suggests that CA based crop management practices can be advocated as sustainable intensification strategy in northwestern India.