Field Crop 2025, Vol.8, No.3, 113-125 http://cropscipublisher.com/index.php/fc 115 and the applied fertilizers can be absorbed and utilized more efficiently. Conversely, an adequate supply of nutrients promotes the absorption and utilization of water by crops, thereby achieving a coordinated improvement in water use efficiency and nutrient use efficiency. This "water and fertilizer synergy effect" is particularly evident under the condition of water and fertilizer integration (Fanish, 2013). Thirdly, the integration of water and fertilizer can achieve precise supply according to the needs of crops. By adjusting the timing and frequency of irrigation and fertilization, it is possible to achieve frequent irrigation with small amounts of water and multiple topdressing with small amounts of fertilizer, avoiding the waste of water and nutrients caused by traditional flood irrigation and large-scale fertilization at one time. 2.3 Coupling effect of drip irrigation and integrated water and fertilizer management in corn production The combination of drip irrigation technology and water and fertilizer integration has played a significant role in coupling and enhancing efficiency in corn production. Firstly, drip irrigation provides an accurate and efficient means of water and fertilizer integration, enabling water and nutrients to be distributed synchronously and evenly in the soil of the corn root zone. This synchronous supply in terms of space and time avoids the significant fluctuations in local soil dryness and nutrient concentration in the traditional way, creates a stable and suitable rhizesphere environment, and promotes the growth of corn roots and nutrient absorption (Figure 1) (Hou et al., 2022). Secondly, the characteristic of small moist areas in drip irrigation keeps the local roots of corn at a relatively high nutrient concentration, which is conducive to improving the efficiency of nutrient uptake. Meanwhile, frequent small-scale irrigation ensures that the soil moisture content does not change drastically due to fertilization, thus avoiding the stress on crops caused by the sudden transition from flood to drought. Research shows that the application of drip irrigation and integrated water and fertilizer technology on summer corn in the north can achieve efficient and coordinated supply of water and nutrients, significantly increasing production compared with the traditional flood irrigation + one-time fertilization treatment. 3 Influencing Mechanism of Water Use Efficiency in Corn Fields 3.1 Characteristics and regulation of soil moisture distribution The spatial distribution of soil moisture under drip irrigation conditions is significantly different from that under the traditional flood irrigation method. The dripper supplies water in a point source manner, forming a "moist body" in the soil. The soil moisture content near the moist area is high, while the soil far from the dripper maintains a relatively low moisture content, creating a distinct moist gradient. This water distribution characteristic ensures that the soil moisture near the root zone of crops is always maintained at an appropriate level, while the soil between rows is relatively dry, thereby reducing ineffective evaporation water consumption. In a typical flood irrigation situation, the excessive water flow causes the soil moisture to become saturated after irrigation and quickly seep to the deep layers, which not only wastes water but may also lead to nutrient leaching loss. However, due to the small amount of water applied each time in drip irrigation, the soil moisture is mainly distributed in the root active layer (such as the 0-40 cm soil layer), and the deep seepage is significantly reduced (Amiri et al., 2019; Gao et al., 2020). This indicates that drip irrigation achieves high-efficiency water supply with "small amounts and multiple times" by altering the pattern of soil moisture distribution. To fully leverage this advantage, it is necessary to rationally regulate the operating parameters of the drip irrigation system, including the flow rate of the drippers, the spacing between drippers, the irrigation cycle and the amount of water injected each time. Through the optimized design of drip irrigation parameters, the size and shape of the moist body can be controlled to match the distribution of corn roots, thereby maximizing water use efficiency. 3.2 Influence of drip irrigation on the water consumption pattern of corn Drip irrigation has significantly changed the water consumption dynamics and process of corn. Under traditional flood irrigation conditions, the water consumption of corn mainly depends on the consumption of soil moisture after irrigation. It is characterized by a rapid increase in soil moisture after irrigation, followed by a gradual decrease in moisture content due to large-scale transpiration of crops and soil evaporation, until a peak occurs again in the next irrigation. The water consumption process shows periodic "sawtooth" fluctuations. Under drip irrigation conditions, due to the high irrigation frequency and small amount of water replenishment each time, soil moisture can be maintained at a relatively stable level. The water consumption of corn is closer to the mode of
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