Impact of Water Management Practices on Winter Wheat Yield and Water Consumption

4.1 Yield and Water Consumption Response to Different Water Management Practices

The present study aimed to investigate the effects of different water management practices on winter wheat yield and water consumption. Our results showed that the minimum irrigation treatment resulted in a significantly lower yield, consistent with previous studies (Gao et al., 2022; Wang et al., 2018; Zhang et al., 2020; Xu et al., 2018). The yield differences among irrigation treatments were highly correlated with the ear number and kernel number per ear, which is in agreement with previous findings indicating that irrigation of bottom moisture water affects the development of these parameters (Wang et al., 2018).

Pre-flowering water stress was found to affect the ear number, as it limits tiller development during nutritional growth, and stress at the pulling stage accelerates stem senescence and reduces spike number (Foulkes et al., 2011; M.Z. Siddiqui and Choudhary, 2017). Additionally, stress at the nodulation stage was found to be important due to reduced seed numbers (Day and Intalap, 1970). Adequate water supply during the flowering period is crucial for reproductive growth and yield formation (Sun et al., 2006). Drought stress before and after flowering and during the stem elongation period negatively affect kernel number per ear, leading to a significant reduction in both the strong and weak grains (B et al., 2000; Zhang et al., 2020). Under drought stress conditions, competition for assimilates between the spike and stem may promote floret degeneration (Zhang et al., 2020).

Our results showed that irrigation at jointing and anthesis could improve grain yield by increasing ear numbers and kernel number per ear (Xu et al., 2018). However, we did not observe a significant difference in thousand-kernel weight among the three treatments, which is not consistent with previous findings (Wang et al., 2018). This may be due to varietal differences or the occurrence of dry heat winds during the filling period, which causes rapid senescence and death of winter wheat and reduces filling rates (Wang et al., 2018). Interestingly, the flowering period of winter wheat under reduced irrigation conditions was a few days earlier than that under conventional irrigation, which helps to avoid dry hot winds during the filling period.

Our results also showed that the Opt and Min practices consumed less water compared to the Con practice, leading to an increase in water use efficiency (Fig. 2), consistent with previous reports (Zhang et al., 1998). The total water consumption mainly consisted of rainfall, irrigation, and soil water depletion. The Min practice had less irrigation and more soil water depletion compared to the Con, indicating more efficient rainfall use compared to the Con practice (Wang et al., 2018).

In summary, our study highlights the importance of water management practices in winter wheat yield and water consumption. The findings emphasize the need for adequate water supply during the flowering period and the negative effects of pre-flowering and drought stresses on ear number and kernel number per ear. The results also suggest that reduced irrigation practices, such as the Min practice, can lead to an increase in water use efficiency and efficient rainfall use. Further studies are needed to explore the varietal differences in response to different water management practices and the potential effects of climate change on winter wheat production.