Food security has become increasingly important globally as well as on domestic fronts as global supply, income growth, and access is not keeping pace with increasing population in developing countries. Increasing resource degradation problems such as groundwater depletion, waterlogging, salinization, soil erosion, loss of biodiversity, and invasive species further add to food security challenges (Oliver and Gregory, 2014).
In the Indian context, the average farm size is very small and the average household member size is large, with poverty and food security prevalent among small land-holders (Pradhan et al., 2015). The issue is not only the availability of food but of its affordability by vulnerable populations in adequate quantity and quality. It is not a question of whether we can increase food production to meet the needs of the rising population, but whether we can do so in a sustainable manner. It is imperative to develop a long-term strategy that would reduce the vulnerability of the farming community and sustainably intensify agricultural productivity while minimizing the degradation of land and natural resources being used.
Among many sustainable cropping systems available, conservation agriculture (CA) is the one that is based on principles to restrict land degradation and conserve the natural resource base (reduced or zero soil disturbance and permanent organic soil cover) as well as increase food and nutritional security through crop diversification and optimal rotation (FAO, 2013). However, the broad applicability of CA to diverse cropping systems around the globe remains contested (Pittelkow et al., 2015, Giller et al., 2009). Implementation and adoption of all the three principles of CA in resource-poor and vulnerable smallholder farming systems face various issues and challenges, most notably the retention of crop residues due to its strong competition as livestock feed (Giller et al., 2009).
Considering various arguments on justifying the implementation of CA, it must obviously be adapted to local agro-ecological conditions and farmer capabilities and preferences. CA is best conceptualized as an integrated production system that is universally applicable but must be locally adapted. Careful consideration of farmer capabilities and preferences is just as important as understanding the production capabilities of the agro-ecological system. Therefore, successful introduction of CA depends upon adapting and tailoring the basic CA principles to the local context. For this end, a transdisciplinary approach was undertaken to introduce and evaluate CA in the rainfed uplands of Odisha, India for three consecutive years (2011-14) (Table 1). Using a transdisciplinary approach engaged all stakeholders in collaborating on the design for the CA treatments appropriate for the farmers and local environmental conditions leading to significant impacts on economic livelihoods, environmental sustainability, and food security.
To assess the effect of CA under local ecological and socio-economic conditions, the study focused on two basic types of ecosystem services: provisional and regulatory services through five treatments consisting of farmers’ traditional practice (FP) which was conventional tillage (three times plowing) with broadcast of local variety maize (Zea mays L.); and four CA treatments viz., conventional tillage with sole cropped maize using line sowing of the improved maize cultivar ‘Nilesh’ (CT-M); conventional tillage with maize intercropped with the improved cowpea (Vigna unguiculata L. cultivar ‘Hariyalli Bush’) (CT-M+C); reduced tillage (one time plowing) with sole cropped maize (MT-M); and reduced tillage with maize + cowpea (MT-M+C). All the four CA treatments included growing of mustard as a cover crop and retention of its residue in the field.
Under provisional ecosystem services, the performance of CA on crop yield and profitability was assessed through maize and the yield contributions of cowpea and mustard towards maize equivalent yield (MEY) under different treatments. The MEY was calculated based on the yields (kg/ha) of maize, cowpea, and mustard for each of the 46 farming households which took part in the on-farm trials. Profitability was measured using partial budget analysis method that includes total variable cost, gross field benefits, and net field benefits under each treatment. Under regulatory ecosystem services, the soil quality was assessed through calculation of soil quality index (SQI) comprising fourteen variables representing soil physical, chemical, and biological properties. The study also investigated farmer preferences for CA treatments and the criteria/objectives that the farmers used to make their decisions through Analytic Hierarchy Process (AHP).
Results showed that reduced tillage combined with maize-cowpea intercropping (MT-M+C) followed by mustard residue retention had higher system productivity and net benefits, an increase of 200% and 230%, respectively over farmers’ practice. Under regulatory ecosystem services, the soil quality was assessed through calculation of soil quality index (SQI) which was highest under MT-M+C followed by mustard residue retention and lowest under farmers’ practices.
In terms of CA treatments before on-farm trials, farmers in this study indicated an equally strong preference for treatments MT-M+C (0.347) and CT-M+C (0.366), compared to FP (0.141) and no intercropping trials. As such, farmers had a preference for treatments that included cowpea because of its higher value in the market (compared to maize) and nutrition to the family and the soil, leading to increased yield. After practicing CA for 2 years, farmers preferred MT-M+C (0.579), the most innovative of the four treatments, providing the best optimal outcome compared to existing conventional farmer practices.
Combined, these results clearly demonstrate the potential of CA to simultaneously increase yield, diversify crop production, and improve soil quality; these results should support a move toward sustainable intensification of crop production to improve future household income and food security.
Utilizing a transdisciplinary approach that engaged stakeholders ensured that farmers and officials understood the costs and benefits of CA. Moreover, having farmers directly participating in the co-design and actively engaged in field experiments, the farmers experience firsthand the impact of CA treatments. The AHP pre- and post-on-farm trial surveys demonstrate that stakeholders converge in their preference for the same CA after participating and witnessing the outcome of the field trials.
These findings are described in the article entitled Potential of conservation agriculture (CA) for climate change adaptation and food security under rainfed uplands of India: A transdisciplinary approach, recently published in the journal Agricultural Systems. This work was conducted by Aliza Pradhan, Catherine Chan, and Brent Sipes from the University of Hawaii at Manoa,, Pravat Kumar Roul from the Orissa University of Agriculture & Technology, and Jacqueline Halbrendt from Wageningen University.