Diversified Agroforestry for Climate Change Adaptation and Mitigation in the Himalayan Region: Potential for Achieving Multiple Benefits

Abstract

Land management and forests are crucial to tackling the concurrent issues of sustainable food production and climate change. Conventional modern agriculture, converting forests and naturally vegetated landscapes to farms and rangelands, contributes significantly to elevate carbon in the atmosphere. Agroforestry systems offer potential for local communities to meet livelihood needs while simultaneously adapting to and mitigating climate change. Data from several studies conducted in nine districts of central Nepal between 2007 and 2017 were analyzed. Forests and agroforestry systems in three central Nepal districts had significantly higher total carbon stocks than agricultural soils (2–5 times) due to high above and below-ground biomass carbon and SOC stocks. The application of improved FYM compost, cattle urine and biochar in four districts increased average SOC by 2.75% over 6 years, translating to an increase of nearly 100 t ha−1 in SOC stock. Along with soil quality benefits, biochar and FYM compost improved the yields of soybean, potato, millet and Swertia chirayita yields which were significantly higher than in untreated plots. The flux of N2O was significantly lower in biochar-amended soil compared to non-biochar. Crop diversification incorporating high-value horticultural and medicinal crops enhance economic returns as indicated by higher benefit-cost ratios for vegetable and Swertia chirayita than for cereals.