Insights for climate change adaptation from early sowing of wheat in the Northern Indo-Gangetic Basin

Early sowing of wheat has been proposed as an important crop management practice for reducing the threat of terminal heat stress – a threat which is likely to increase under climate change projections for the Indo-Gangetic Basin (IGB) of South Asia, home to more than 400 million people. However, to date there is little empirical evidence for the impacts of early sowing on productivity and profitability outcomes. Using farm survey data collected from the Northern IGB in Nepal and remotely sensed climate data, this study assesses the factors associated with farmers' early sowing decisions and the impact of sowing date on wheat productivity, costs, and returns. We used a quasi-experimental approach to assess the impacts of early sowing on outcome variables. We find that early sowing enhances wheat productivity (236–241 kg/ha; 10–11%) and profitability (US$ 54–55 ha⁻¹). However, we also find that early sowing has heterogenous effects. Large farms (>0.8 ha) and wheat plots receiving higher seasonal precipitation (>90 mm) have the largest expected gains in productivity and profitability. The adoption of early sowing of wheat is associated with farm size, seasonal precipitation, and farmers' crop management practices such as delay in harvesting of the previous season's crop. Our findings suggest that early sowing can enhance wheat productivity and profitability, and reduce risk of terminal stress, which in turn can increase the sustainability of smallholder wheat production in the IGB under forecasted climate change.