To investigate co-ridge planting (RIC) effects on soil water distribution characteristics and interspecific water reciprocal utilization (ΔΔSWS CO- ) in maize intercropped with peanuts (maize||peanut), a field experiment was conducted with root separation (eliminated belowground interspecific effects) and no separation (existing belowground interspecific interaction) conditions, using flat planting (FIC) as control. This study examined RIC effects on soil water distribution, soil water storage (SWS), ΔΔSWS CO- , yield, and water use efficiency (WUE) in 0–100 cm soil layer. Soil water distribution under FIC showed “ ” and “ ” patterns in one planting unit (one row of maize and two of peanuts) under drought and flood conditions, respectively, while the RIC showed “ ” and “ ” patterns. Compared to FIC, the soil water content and SWS were higher and lower in the maize and peanut strips in the 0–60 cm soil layer under RIC, respectively. For RIC, under flood conditions, root separation reduced the soil water content and SWS in maize and peanut strips at 0–60 cm compared to those in the no root separation. During drought, this occurred in the maize strip at 0–40 cm, whereas both indices increased in the peanut strip at 0–60 cm. RIC increased the ΔΔSWS CO- under both conditions with phosphorus (P 180 ) application compared to FIC. Maize and peanut yields, WUE, water equivalent ratio (WER), and land equivalent ratio (LER) were higher under RIC than FIC. Under RIC, maize and peanut yields, WUE, and WER were lower with root separation than those with no separation, suggesting that RIC benefits yield and WUE in maize||peanut systems. RIC creates alternating “wet-and-dry” soil ridge-furrow environments, facilitating soil water absorption and utilization by the maize strip and creating a suitable soil water environment for the peanut strip, thereby fulfilling the water needs of both crops and promoting ΔΔSWS CO- . • Co-ridge planting (RIC) promotes the absorption of soil water from the maize strip to the peanut strip. • RIC allows maize||peanut to form alternating “wet-and-dry” ridge–furrow distribution environments. • RIC improves soil water distribution, and regulates water storage. • RIC coordinates the maize and peanut water demand differences and promotes interspecific water reciprocity. • RIC improves maize||peanut yields and water intercropping advantage.
Li et al. (Fri,) studied this question.