Establishing desirable cropping systems with higher fertilizer-use efficiency and lower risk of environmental pollution is a promising approach for more sustainable agriculture development. Intercropping may facilitate phosphorus (P) uptake and reduce P-fertilizer application rates. However, how root-root interactions mediate enhanced P-fertilizer-use efficiency in intercropping under field conditions remains poorly understood. Using a long-term field experiment established in 2009, where there have been three P-fertilizer application rates (0, 40, and 80 kg P ha⁻¹) and nine cropping systems (four intercropping combinations and corresponding monocultures), we calculated aboveground biomass, grain yield, aboveground P content, P-use efficiency indicators, e.g., the apparent recovery efficiency of applied P, and diversity effects. We also investigated the P-related physiological and morphological traits of crop species and linked root traits with agronomic indicators. We found that 12 years of intercropping significantly increased productivity, shoot P content, agronomic efficiency of applied P, and the apparent recovery efficiency of applied P in all combinations compared with the weighted means of corresponding monocultures; intercropping with 40 kg P ha⁻¹ application showed relatively high productivity, P content and P-use efficiency. The P-uptake advantage in intercropping was mainly related to the positive complementarity effect. The companion crop species (i.e. faba bean, oilseed rape, chickpea, and soybean) exhibited greater P-mobilizing capacity than sole maize. Intercropped maize exhibited greater root physiological, e.g., rhizosheath phosphatase activity and carboxylates (proxied by leaf manganese concentration), and morphological traits (e.g., specific root length) than sole maize, partly related to facilitation by efficient P-mobilizing neighbors. The greater P-use efficiency was mainly contributed by morphological traits of maize rather than traits of companion crop species. We highlight that the enhanced P-use efficiency in intercropping systems is partly mediated by belowground facilitation, and desirable intercropping systems have the potential to save P-fertilizer input and improve the sustainability of P management in agroecosystems.

建立具有更高肥料利用率和更低环境污染风险的理想种植制度是实现农业可持续发展的一个有前景的方法。间作可以促进磷 (P) 的吸收并减少磷肥的施用量。然而，在田间条件下，根与根的相互作用如何介导提高间作磷肥的利用效率仍然知之甚少。使用 2009 年建立的长期田间试验，其中存在三种磷肥施用量（0、40 和 80 kg P ha ⁻¹）和九种种植制度（四种间作组合和相应的单一栽培），我们计算了地上生物量、粮食产量、地上磷含量、磷利用效率指标（例如施用磷的表观回收效率）和多样性效应。我们还研究了作物物种与磷相关的生理和形态特征，并将根系特征与农艺指标联系起来。我们发现，与相应单一栽培的加权平均值相比，12 年的间作显着提高了所有组合的生产力、地上部磷含量、施用磷的农艺效率以及施用磷的表观回收效率；间作 40 kg P ha ⁻¹应用表现出较高的生产率、磷含量和磷利用效率。间作吸磷优势主要与正互补效应有关。伴生作物品种（即蚕豆、油菜、鹰嘴豆和大豆）表现出比单一玉米更强的磷动员能力。间作玉米比单作玉米表现出更强的根部生理学特征，例如根鞘磷酸酶活性和羧酸盐（由叶锰浓度代表）和形态特征（例如特定根长），部分与高效磷动员邻居的促进作用有关。更高的磷利用效率主要是由玉米的形态特征而非伴生作物物种的特征决定的。