# Evaluation of cotton production sustainability and water footprints in the oasis area of southern Xinjiang under climate change

## TL;DR

This study evaluates how climate change affects cotton production and water use in southern Xinjiang, finding that future conditions may reduce water needs while improving yields and sustainability.

## Contribution

The study introduces a comprehensive evaluation of cotton sustainability and water footprints under future climate scenarios using the AquaCrop model and CMIP6 data.

## Key findings

- Future climate scenarios project a 29.3-42.6% reduction in cotton water footprints and a 39.8-50% increase in yield.
- Eliminating film mulching and reducing irrigation quotas under future climates may not harm yield sustainability.
- Irrigation strategies need to adapt to maintain productivity and water efficiency in response to climate change.

## Abstract

The sharp increase in temperature and changes in other climatic variables have profoundly impacted cotton growth, posing a significant threat to the stability of cotton yields in the oasis region of southern Xinjiang.

This study employed the AquaCrop model (Version 6.1) and CMIP6 SSP245BCC-CSM2-MR future climate scenario data to comprehensively evaluate the impacts of different irrigation and mulching methods on cotton water consumption, water footprints (blue and green water footprints), crop yields, and their long-term stability and sustainability from 2021 to 2099.

Increasing temperatures under future climate change scenarios could significantly reduce cotton water consumption and water footprints, while increase cotton yield, yield stability, sustainability, and overall irrigation water productivity (WP). Compared to the baseline period of 1981–2020, cotton water consumption and water footprints in 2021–2060 and 2061–2099 are expected to decrease by 29.3% and 28.8%, and 41.6% and 42.6%, respectively. Concurrently, cotton yield and WP are projected to experience an increase of 39.8% (50%) and 49.2% (60.25%), respectively. A comprehensive evaluation based on Technique of Order Preference by Similarity to Ideal Solution revealed that under the historical climate conditions from 1981–2020, an irrigation quota of 495 mm for film mulching drip irrigation and 594 mm for filmless drip irrigation exhibited favorable effects on cotton yields but resulted in increased irrigation water consumption. However, under the future climate scenarios for the periods of 2021-2060 and 2061-2099, the elimination of film mulching and a reduction in irrigation quotas are not expected to have a detrimental impact on the sustainability and stability of cotton yields. This study provides valuable insights for enhancing the resilience and productivity of cotton in response to climate change in southern Xinjiang and analogous regions, which hold significant for policymakers to formulate strategies for the sustainable development of agriculture and plan the allocation of water resources in the future.