Evaluating the impact of irrigation on ecosystems services (ES) and smallholder resilience in Nepal

Empirical evidence on the impact of irrigation on ecosystem services and smallholder resilience is lacking, with a few existing studies showing mixed results. For example, while some studies argue that irrigation contributes to crop diversity by extending the growing season and broadening crop choices, others show that irrigation leads to reduced crop diversity due to mono-cropped high-yield varieties replacing local varieties. In addition to its important implications for nutrition, dietary diversity, and risk management, crop diversity is an important landscape feature that often links to the provision of insect-based ecosystem services such as biological pest control and pollination. Evidence on the impact on land use change is also lacking. While some have argued that irrigation reduces pressure on the surrounding forest resource, grazing and marginal lands because of increased cropping intensification, others have suggested a reverse trend. The exact changes remain unclear and need to be quantified in order to understand the impact on natural/semi-natural and fragile ecosystems. Furthermore, a deeper look is needed to understand how irrigation has contributed to farmers’ resilience to natural and social shocks by examining important factors such as access to irrigation, seasonality of irrigation, and multiple use of water.