Optimizing plant type structure to adjust the temporal and spatial distribution of water consumption and promote the growth and yield formation of cotton

Global warming leads to further shortage of agricultural water resources. Understanding the water consuming characteristics of different cotton cultivars is crucial for efficient utilization of water resources and yield increasing. However, there is little evidence about the effects of cotton cultivars with different plant-type structures on yield formation and temporal and spatial distribution of water consumption. A two-year experiment was conducted at the Cotton Research Institute of the Chinese Academy of Agricultural Sciences in 2020 and 2021 to evaluate the water consumption of six cotton cultivars with different plant-type structures cotton using spatial grid method and water balance method combined with 5TE sensor. The leaf area index (LAI), biomass, yield and spatial distribution of bolls were also measured and analyzed. The results showed that the loose-type cultivars consumed more soil water than the compact-type cultivars, which was due to the higher water consumption in the 40–120 cm soil layer. The cumulative water consumption and water consumption of each soil layer (0–40 cm 40–80 cm and 80–120 cm) of different cotton cultivars had significant quadratic function relationship with LAI, and had significant linear positive correlation with biomass accumulation (aboveground biomass and underground biomass), with R2 greater than 0.8. When consuming the same amount of water, loose-type cultivars produced more biomass and larger green leaf area than compact-type cultivars. However, the yield-increasing and water-saving effects of the two plant-type structure cotton cultivars were similar, while SCRC 28 and Ji 228 have higher yield and water use efficiency (WUE), which were suitable to be popularized and planted in the cotton area of the Yellow River basin. Cotton yield was significantly negatively correlated with boll setting rate in upper canopy and water consumption in 0–40 cm soil layer, and the R respectively were − 0.82 and − 0.69; it was positively correlated with boll setting rate in lower canopy and water consumption in 80–120 cm soil layer, and the R respectively were 0.75 and 0.64. Therefore, increasing the WUE of 0–40 cm soil layer and water consumption in 80–120 cm soil layer was beneficial to high yield of cotton. By optimizing the structure of different plant types, the temporal and spatial distribution of water consumption of cotton can be adjusted, and the yield of cotton can be effectively improved. The results can provide a basis for cotton cultivar selection and precision irrigation management.