Crop-climate model in support of adjusting local ecological calendar in the Taxkorgan, eastern Pamir Plateau

Climate variability and changes threaten agriculture. In response, farmers have been forced to adjust farming practices according to locally available options. Ethnoecological knowledge of surrounding environmental events inform such adjustments. This study aims to explore observed changes in the crop calendar and changes in crop yield as response to climatic variability to support adjusting the local crop calendar. Interviews with local leaders and group discussions with farmers were organized. Climatic indices such as growing degree days (GDD) and crop evapotranspiration (ETc) were calculated and regressed with crop production data (1988–2017) from Taxkorgan County of Xinjiang, China, using the partial least square regression (PLS) technique. Survey data revealed that the sowing dates of important crops began earlier than previous decades. Spatial data showed that the growing season advanced 3.2 days per decade. PLS results suggest that GDD and ETc significantly affect crop yield. GDD during the growth period had a significant positive impact, indicating that recent warming is beneficial for crop yields in these regions. ETc during the growth period mostly had a negative impact, suggesting the need for ample water to improve crop yields in the context of further warming. The current shift in sowing is corroborated by early heat accumulation, and crop calendar adjustments can reasonably increase yields. Our results are applicable to agricultural decisions at the farm level following site-specific fieldwork. Optimal planting dates can be determined by combining results from our study and other suitable farming practices to strengthen the resilience of local ecological calendars to climate change.