Impact of legume intensified crop rotations and tillage practices on maize productivity vis-à-vis C and N dynamics of a sandy loam soil in north-western Indo-Gangetic Plains of India

The study was conducted to evaluate long-term effect of legume intensified maize based crop rotations and contrasting tillage practices and a experiment was laid out in split plot design with three tillage practices i.e. zero tillage (ZT), permanent bed (PB) and conventional tillage (CT) as main plot treatments and four legume intensified crop rotations (MWMb maize-wheat-mungbean, MCS-maize-chickpea-Sesbania, MMuMb-maize-mustard-mungbean and MMS-maize-maize-Sesbania) as sub-plot treatments. Adoption of CA based tillage practices (ZT/PB) significantly improved maize protein yield (MPY). ZT/PB gave 7.7–14.2% higher MPY(Maize protein yield and 7.4–13.0% higher MPYA (maize protein yield for adults) over CT. Similarly, the MPY and MPYA under legume intensified cereal based rotations were invariably higher in MCS and MWMb systems compared to MMuMb and MMS rotations. The total soil nitrogen (TSN) 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, among the legume intensified rotations the maize planted under MCS and MWMb rotations registered 11.3–18.0% (0-15cm) and 8.411.0% (15-30cm) higher TSN over MMuMb and MMS rotation. Similarly, adoption of the CA practices (ZT/PB) resulted into significant improvement in soil organic carbon (SOC) stocks compared to CT. ZT and PB among the tillage practices and MCS crop rotations among the sub-plot treatments registered higher Leaf area index (LAI) and net assimilation rate (NAR) compared to other management practices. Interaction effect of tillage practices and crop rotations were significant for MPY, MPYA, TSN and SOC stocks and all these parameters were reported maximum with ZT-MCS. Thus, our study suggests that CA based crop management with legume diversified maize based rotations (MCS and MWMb) can be advocated as sustainable intensification strategy in north-western India and other similar agro-ecologies of South Asia.