Peer review

Responding to increasing demand from poultry and fish feed industries, maize area is rapidly expandingin South Asia. Current tillage and crop establishment (TCE) practices are however associated with highlevels of input use, including direct and indirect forms of energy. In Bangladesh, policy makers emphasizethe need to reduce the USD 1.4 billion year−1agricultural energy subsidy. Bangladeshi farmers cultivatemaize during the winter rabi season, when yield potential is high. But when poorly managed, farm-ers’ investments in TCE practices may erode farm-level profitability, while inefficiently utilizing energy.Resource-conserving TCE options may however provide an alternative for maintaining or raising yields,while increasing farmers’ income and reducing energy use. We present a multi-criteria assessment of theproductivity, profitability and energetics of alternative TCE options, including zero (ZT), reduced (RT), andstrip tillage (ST), in addition to fresh (FBs) and permanent bed planting (PBs), contrasted with conventionaltillage (CT) in Bangladesh’s main maize producing agro-ecological zones (AEZs). Trials were conductedin 184 farmers’ fields in Bangladesh’s northwestern districts with coarse-textured soils (Rangpur andRajshahi in AEZs 3 and 11, respectively) and in one eastern district with fine-textured soils (Comilla inAEZ 19). Trials spanned the 2009–2010 to 2012–2013 rabi seasons. Significant TCE effects on grain yieldwere observed in AEZs 3 and 11, but not in AEZ 19. Compared to CT, grain yields under FBs, PBs and ST weresignificantly higher in AEZ 3, and also under FBs and PBs in AEZ 11. Production cost was 7.8% lower, whilenet profit and benefit-to-cost ratios for the alternative TCE options were 13.7 and 20% greater than CT,although data were inconsistent in AEZ 19. Across AEZs, total energy inputs were significantly higher forCT (30.3.5 × 103to 33.8 × 103MJ ha−1) compared to alternative options (28.3 × 103to 32.7 × 103MJ ha−1).Permanent beds required the lowest diesel energy compared to CT. Similarly, energy use efficiency (EUE)was significantly higher for PBs and ST compared to CT in AEZ 3 (7.17–8.08 MJ MJ−1) and for PBs and FBsin AEZ 11 (8.55–10.26 MJ MJ−1). Among all options, PBs, FBs and ST provided greater benefits in terms ofincreased yield and profits, increased EUE, and reduced economic risks in AEZs 3 and 11, but less so inAEZ 19. Poor performance in the latter region was due mainly to poorly-drained low- to medium-lowland types that delayed maize planting and impeded optimal establishment. Further efforts are neededto untangle the determinants of spatially variable performance to refine recommendation domains forTCE options for maize in South Asia.

Conservation Agriculture Program

INT3262

INT3222

INT3018

INT3034