Water and heat resource utilization of cotton under different cropping patterns and their effects on crop biomass and yield formation

Abstract

• A new method for visualizing the spatiotemporal change in soil water consumption. • The complexity of crop responses to multiple environmental factors is highlighted. • The main factor driving cotton biomass formation is water consumption. • Cotton yield exhibits a significant positive correlation with PE GDD and PE soil . • MC and WIC had high cotton yield and accumulated temperature production efficiency. In the context of intensified climate change, approximately 70% of global cotton ( Gossypium hirsutum L.) production is in arid or high temperature environments. Improving cultivation practices is an effective measure to promote the adaptation of cotton production to the climate. To comprehensively study the characteristics of the hydrothermal microclimate in cotton fields and their relationship with cotton biomass and yield formation, a grid sampling method based on sensors with high spatiotemporal resolution was used in this study to monitor the soil temperature and soil moisture under three cropping patterns (monoculture cotton (MC), wheat ( Triticum aestivum L.)/delayed intercropped cotton (WIC), and wheat/direct-seeded cotton (WDC)). The cropping patterns substantially changed the cotton hydrothermal resource utilization. WDC was the pattern with low cotton yield and low hydrothermal resource use efficiency, while MC and WIC were the patterns with high cotton yield and high accumulated temperature production efficiency. Cotton yield exhibited a very significant positive correlation with the accumulated temperature production efficiency of air and soil, and these relationships were less affected by different planting patterns. The climate in 2016 was relatively humid, and the water consumption (WC) of MC was mainly concentrated within a soil depth of 70 cm, WIC was 50 cm, and WDC was 30 cm. The climate in 2017 was relatively dry, and the main soil depth ranges of WC in MC, WIC, and WDC were 50, 30, and 20 cm, respectively. WC was the most important factor affecting cotton biomass, especially reproductive organ biomass, followed by the effective accumulated air temperature. The WC of cotton was most affected by changes in soil moisture at a depth of 30 cm. This study strengthens the application of smart agricultural technology in sustainable cotton production and highlights the complexity of crop responses to cultivation practices and multiple environmental factors.