Assessment of diverse tillage system with mulching for water-cum-energy efficiency and soil carbon stabilization in maize (Zea mays L.)-rapeseed (Brassica campestris L.) system.

A combination of intensive soil manipulation, low water and input efficiencies has resulted in declining soil and crop productivity, and a worsening soil organic carbon (SOC) stock and crop productivity in the eastern Himalayan agro-ecosystem. There is an urgent need to improve the carbon (c) stability with water-cum-energy efficient management for long-term sustainability. Experimental field was practiced under limited tillage with power tiller-based tilling for ten years (2001–2010). This experiment was designed for two years (2011 and 2012) with three tillage practices in the main-plots: i) conventional tillage (CT), ii) minimum tillage (MT), and iii) zero tillage (ZT), while in the sub-plots crop residues mulch (CRM): a) CRM at 4 Mg ha−1 and b) no mulch (NM) was practiced under rainfed conditions. Results show that grain yield of maize improved by 16–31% in CT, whereas rapeseed yield improved by 26–28% with MT as compared to ZT during both the years. CRM improved the yield by 6–11% in maize and 20–25% in rapeseed over NM. Moreover, per plant biomass accumulation improved with CT+CRM by 42–44% in maize and MT+CRM by 10–24% in rapeseed during the both years. Likewise, CT maize and MT rapeseed along with CRM used water was recorded 378–467 and 200–201 mm. Moreover, similar trend was observed on water use efficiency (WUE) by 8.5–10.2 and 4.9–5.4 kg ha−1 mm−1, respectively. In terms of energy, CT and MT along with CRM were more energy exhaustive practices in both the crops; while in ZT recorded higher energy use efficiency (9.3 and 7.7) and productivity (0.7 and 0.4 kg MJ−1) in CT and MT, respectively. Adoption of ZT also increased bulk density (ρb) by 3% over CT. The ZT along with CRM improved C stability by 6 folds than CT and 58% over NM. Considering all these facts, CT/MT along with CRM may be recommended to obtain higher yield, WUE, energy productivity and C stability in (Zea mays L.)- rapeseed (Brassica campestris L.) system in the eastern Himalayan agro-ecosystem. • Higher yield obtained under CT with CRM in maize and MT with CRM in rapeseed. • Water use efficiency enhanced under CT in maize and MT in rapeseed coupled with CRM. • ZT and CRM augmented energy parameters, SOC and C stabilization. [ABSTRACT FROM AUTHOR]