Intercropping regulation of soil phosphorus composition and microbially-driven dynamics facilitates maize phosphorus uptake and productivity improvement

Intercropping is a powerful way that promote a more diversified plant community in croplandas. It is important to understand how this practice regulates phosphorus (P) footprint and trade-off in plant-soil system which influences crop productivity. Herein, a field-based experiment was conducted to investigate the effects of intercropping of maize with legumes (peanut and soybean) and non-legumes (gingelly and sweet potato) on maize productivity and P transformation and regulation. Compared with the monoculture, intercropping treatments increased maize yield, P use efficiency (PUE), P partial factor productivity (PFPP), and aboveground P uptake by 13.3–34.4%, 6.2–41.2%, 13.6–68.2%, and 10.3–20.1%, respectively. Intercropping treatments significantly reduced the cumulative losses of total P, dissolved P, and particulate P by 4.7–60.1%, 3.2–67.1%, and 2.7–64.7%, respectively. Maize/peanut and maize/soybean systems showed a better advantage in improving maize productivity and mitigating P runoff loss than the maize/gingelly and maize/sweet potato. Compared with the monoculture, intercropping increased the contents of soil labile-P, stable-P, solution-P, hydrolysable-P, and exchangeable-P by 3.1–7.8%, 18.7–63.2%, 8.4–35.5%, 0.2–28.3%, and 38.6–637.1%, respectively. The potential activities of soil alkaline and acid phosphatase in intercropping treatments increased respectively by 15.3–173.7% and 5.6–215.2% compared with the monoculture. Maize productivity components (crop yield, PFPP, and PUE, and plant P uptake) were positively correlated with soil P composition and bioavailability, microbial biomss P, and phosphatase activity, while negatively correlated with P runoff loss (P < 0.05). Those findings highlight the importance in understanding how soil P composition and microbially-driven P dynamics mediates plant P uptake to determine the consequences of intercropping for maize productivity. • Intercropping increased maize yield and PUE by 13–34% and 6–41%, respectively. • Intercropping decreased the runoff loss of TP, DP, and PP by 5–60%, 3–67%, and 3–65%. • Intercropping increased soil phosphatase activities by 6–215% with maize development. • Increased productivity was related to soil P composition, bioavailability, and dynamics. • Intercropping-driven plant-soil P trade-off contributed to maize productivity improvement.