Abstract
In controlled-condition field trials across South Asia, zero-tillage (ZT) has demonstrated considerable scope for enhancing wheat productivity in the Indo-Gangetic Plains (IGP) while using less energy and irrigation water. However, studies that quantify the impact of ZT in farmers’ fields are scarce, especially in the less productive and densely populated Eastern IGP, an area that the Indian government is targeting for investment to address current and future food insecurity. Furthermore, a recent global meta-analysis has questioned the yield benefits of ZT, especially when permanent soil cover with crop residues is not maintained. To assess the real-world performance of ZT wheat in Eastern India, we quantified the productivity impact of current ZT practices in the State of Bihar, based on a random sample of 1000 wheat-growing households, stratified by ZT adoption status. Cobb-Douglas stochastic production frontiers estimated the effect of ZT on wheat output while controlling for potential selection bias between ZT users and non-users regarding crop management. In contrast to the global meta-analysis, we found that the prevailing ZT practices without full residue retention led to a robust yield gain over conventional-tillage wheat across different agro-ecological zones, amounting to 498 kg ha−1 (19 %), on average. The economic benefit from ZT related yield increase and cost savings in wheat production amounted to 6 % of total annual income among sampled households. We conclude that ZT users reap substantial benefits, and that ZT technology could play a major role in making Bihar self-sufficient in wheat. To increase access to the technology among smallholders, an expansion of the network of ZT service providers is essential and can be supported through targeted policies and development interventions.
Highlights
Enhancing the productivity of the rice-wheat cropping systems in the Indo-Gangetic Plains (IGP) is of utmost importance for ensuring food security for more than 20 % of the global population (Erenstein et al 2008; Chauhan et al 2012)
In recognition of the pervasive yield gaps that characterize the Eastern IGP along with a wealth of under-developed water resources (Aggarwal et al 2004; DoA 2008), Indian policy makers have turned their attention to meeting both state-level and national foods needs through intensification in the East through programs such as ‘Bringing the Green Revolution to Eastern India (BGREI)’
Our estimated ZT induced wheat yield gain of 498 kg ha−1 in farmers' fields is in line with findings from field trials: in seven on-station trials conducted in the Eastern IGP, the average ZT induced yield increase in wheat amounted to 15 %, or 460 kg ha−1 in absolute terms (Erenstein and Laxmi 2008); at 490 kg ha−1, the average yield gain reported from on-farm trials in Bihar is very similar to our estimates of what farmers achieve with their own management (Dhiman et al 2003)
Summary
Enhancing the productivity of the rice-wheat cropping systems in the Indo-Gangetic Plains (IGP) is of utmost importance for ensuring food security for more than 20 % of the global population (Erenstein et al 2008; Chauhan et al 2012). The regions that currently supply wheat to Bihar, such as the Northwestern state of Punjab where wheat yields averaged 4.59 MT ha−1 over the same five-year period (MoA 2013), have comparatively little scope for further boosting yields (Aggarwal et al 2004). Exacerbating this scenario, there are strong imperatives in Northwestern India to reduce water resource utilization in agriculture to arrest the dramatic declines in groundwater levels that are undermining the sustainability and environmental footprint of production (Humphreys et al 2010). Identifying technical entry points and strengthened support systems for innovation that will contribute to agricultural intensification in a manner that is environmentally sustainable, socio-economically tenable, and – just as importantly - broadly scalable among smallholders presents a formidable challenge
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
