Legume rhizodeposition promotes nitrogen fixation by soil microbiota under crop diversification. This study investigates how different crop combinations influence the interaction between peanut plants and their rhizosphere microbiota through metabolite deposition and functional responses of free-living and symbiotic nitrogen-fixing bacteria. Using an 8-year diversified cropping field experiment, the research found that peanut co-cultured with maize and oilseed rape led to specific changes in peanut rhizosphere metabolite profiles and bacterial functions, enhancing nitrogen fixation and root nodulation. Flavonoids and coumarins accumulated due to the activation of phenylpropanoid biosynthesis pathways in peanuts, which enhanced the growth and nitrogen fixation activity of free-living bacteria and root nodulation by symbiotic Bradyrhizobium isolates. The findings demonstrate that tailored intercropping can improve soil nitrogen availability through changes in the rhizosphere microbiome and its functions. Chemical signaling between plants and soil microbiota plays a critical role in microbial symbioses and rhizosphere microbiome assembly. Root exuded secondary metabolites attract and filter species-specific microbial taxa, including those that complement the host's functional repertoire. In turn, compounds released by rhizosphere microbes trigger plant responses that further adjust microbiome specificity and composition. This continuous chemical dialog is reflected in the metabolic deposition of the host plant rhizosphere, known as rhizodeposition. Although significant mechanistic insights have been obtained on rhizosphere chemical signaling and rhizomicrobiome assembly of individual plant species, much less is known about how these processes are influenced by interspecific interactions between coexisting plant species. Interspecific neighbor-driven species recognition can induce a metabolic response in the neighbor and change the chemical composition of its rhizosphere. Such chemical alterations theoretically drive subsequent changes in the structure and function of the rhizomicrobiome. However, recent field studies on chemical feedbacks between plant species have focused more on non-kin species defense, and less on how these chemical cues may alter the rhizomicrobiome and microbially mediated functions that affect the plant fitness of the species involved. The question of how interspecific effects on plant fitness are shaped by rhizomicrobiome feedbacks is particularly relevant in the context of diversified cropping systems, in which crop species diversity is increased in space and time. Field studies on such systems often demonstrate improved performance of key food crops, especially in intercropping systems including legumes. One of the keys to the success in these systems is improved nitrogen availability through biological nitrogen fixation, both by free-living bacteria and rhizobial symbiosis with legumes. The latter, in particular, requires finely tuned reciprocal signal transduction systems as the host plant has to reprogram root growth and invest in nodule structures before any gain from the symbiosis is measurable. These processes are likely to be influenced by the other (non-legume) crops in the system. By identifyingLegume rhizodeposition promotes nitrogen fixation by soil microbiota under crop diversification. This study investigates how different crop combinations influence the interaction between peanut plants and their rhizosphere microbiota through metabolite deposition and functional responses of free-living and symbiotic nitrogen-fixing bacteria. Using an 8-year diversified cropping field experiment, the research found that peanut co-cultured with maize and oilseed rape led to specific changes in peanut rhizosphere metabolite profiles and bacterial functions, enhancing nitrogen fixation and root nodulation. Flavonoids and coumarins accumulated due to the activation of phenylpropanoid biosynthesis pathways in peanuts, which enhanced the growth and nitrogen fixation activity of free-living bacteria and root nodulation by symbiotic Bradyrhizobium isolates. The findings demonstrate that tailored intercropping can improve soil nitrogen availability through changes in the rhizosphere microbiome and its functions. Chemical signaling between plants and soil microbiota plays a critical role in microbial symbioses and rhizosphere microbiome assembly. Root exuded secondary metabolites attract and filter species-specific microbial taxa, including those that complement the host's functional repertoire. In turn, compounds released by rhizosphere microbes trigger plant responses that further adjust microbiome specificity and composition. This continuous chemical dialog is reflected in the metabolic deposition of the host plant rhizosphere, known as rhizodeposition. Although significant mechanistic insights have been obtained on rhizosphere chemical signaling and rhizomicrobiome assembly of individual plant species, much less is known about how these processes are influenced by interspecific interactions between coexisting plant species. Interspecific neighbor-driven species recognition can induce a metabolic response in the neighbor and change the chemical composition of its rhizosphere. Such chemical alterations theoretically drive subsequent changes in the structure and function of the rhizomicrobiome. However, recent field studies on chemical feedbacks between plant species have focused more on non-kin species defense, and less on how these chemical cues may alter the rhizomicrobiome and microbially mediated functions that affect the plant fitness of the species involved. The question of how interspecific effects on plant fitness are shaped by rhizomicrobiome feedbacks is particularly relevant in the context of diversified cropping systems, in which crop species diversity is increased in space and time. Field studies on such systems often demonstrate improved performance of key food crops, especially in intercropping systems including legumes. One of the keys to the success in these systems is improved nitrogen availability through biological nitrogen fixation, both by free-living bacteria and rhizobial symbiosis with legumes. The latter, in particular, requires finely tuned reciprocal signal transduction systems as the host plant has to reprogram root growth and invest in nodule structures before any gain from the symbiosis is measurable. These processes are likely to be influenced by the other (non-legume) crops in the system. By identifying