Conservation Agriculture Technologies for Cropping Systems Sustainability and Food and Nutrition Security in Nepal

Recent global experiences on sustainable intensification of smallholder cropping systems show that improving food security and income with reduced production inputs and increased systems sustainability would be possible through the adoption of conservation agriculture (CA) technologies. CA-based sustainable intensification follows three principles in farming, viz. minimum soil disturbance, crop residue retention, and diversified and sustainable crop rotations. CA aims at improving productivity, reducing production costs, and increasing farmers’ income through reduced use of labor, energy, and other farm inputs, and improving the sustainability of cropping systems. Resource-conserving technologies (RCTs) include at least one of the three principles of CA and aim at reducing the use of external inputs. This chapter reviews the application of CA and RCTs for improving the sustainability of cereal-based cropping systems mainly in the context of Nepal but with relevance to the Eastern Indo-Gangetic Plains. The review, complemented with the authors’ own results from several on-station and on-farm experiments, demonstrated that the CA and RCTs practices viz. dry direct-seeded rice, unpuddled transplanted rice, and zero-tillage maize, wheat and legumes with the retention of crop residues can increase grain yields and profits and save labor and water use compared to conventional tillage practices. No or minimum tillage along with residue retention can also suppress weeds, increase opportunity for crop diversification, improve soil physico-chemical and micro-biological properties, enhance nutrient- and energy-use efficiencies, and reduce greenhouse gas emissions. CA practices encourage the use of land leveling, farm mechanization, and precision crop production. CA and RCTs have also the potential for reducing soil erosion in sloping hilly areas and undulating land with narrow terraces. Despite several advantages, these technologies have however not been fully mainstreamed in the national agricultural research and extension system of Nepal. Knowledge gaps among extension workers, farmers, and other citizens, unavailability of farm machinery, trade-offs in using crop residues for improving soil fertility and animal feed, land fragmentation, poor rural infrastructures, and inadequate policy support are the major adoption barriers of CA-based technologies. The review concludes that there is an urgent need to institutionalize the CA and RCTs to attain the sustainability of cropping systems and achieve food, nutrition, and livelihood security of the growing population.