Rhizosphere interactions between intercropping maize and alfalfa to increase phosphorus (P) acquisition remain largely unknown. This study aimed to investigate the mechanisms underlying niche complementarity to increase P acquisition in the maize/alfalfa mixture by influencing root/rhizosphere interactions. Maize was grown alone (single maize) or with maize (maize/maize) or alfalfa (maize/alfalfa) with low P (30 mg P kg⁻¹ soil) and high P (150 mg P kg⁻¹ soil) supplies. The target maize had greater shoot biomass and P content when grown with alfalfa than maize. Compared with maize, alfalfa had higher secretion of carboxylates and acid phosphatase, suggesting a stronger capacity to mobilize soil P. Phosphorus deficiency also increased the specific root length and the proportion of thin roots (diameter < 0.2 mm) in alfalfa, and intercropped alfalfa had higher carboxylates secretion than monocropped one, indicating that alfalfa root traits were modified by both soil P supply and the identity of neighbor. Increased soil P availability by alfalfa root exudation and improved rhizosphere environment by thin alfalfa roots promoted shoot growth and P acquisition of maize in the maize/alfalfa mixture. The presence of maize increased the secretion of carboxylates from alfalfa roots, suggesting that the root interactions between maize and alfalfa are crucial for improving P‐use efficiency and productivity in intercropping.

中文翻译：

---

根际相互作用驱动的生态位互补性提高了玉米/苜蓿混合物中磷的利用效率

间作玉米和苜蓿之间增加磷（P）吸收的根际相互作用仍然未知。这项研究旨在调查潜在的生态位互补机制，通过影响根/根际相互作用来增加玉米/苜蓿混合物中的磷获取量。玉米单独种植（单种玉米），或与低磷（30 mg P kg ^-1土壤）和高磷（150 mg P kg ^-1）的玉米（玉米/玉米）或苜蓿（玉米/苜蓿）一起种植。土壤）用品。与苜蓿一起种植时，目标玉米的茎生物量和磷含量更高。与玉米相比，紫花苜蓿具有较高的羧酸盐和酸性磷酸酶分泌能力，表明其具有较强的动员土壤磷的能力。磷缺乏还增加了紫花苜蓿的比根长和细根比例（直径<0.2 mm），间作紫花苜蓿较高的羧酸盐分泌比单作的高。这说明苜蓿的根系性状受到土壤磷供应和邻居身份的改变。苜蓿根系分泌物增加土壤磷的利用率，苜蓿根部稀疏改善根际环境，促进了玉米/苜蓿混合物中玉米的芽生长和磷的吸收。玉米的存在增加了紫花苜蓿根部羧酸盐的分泌，