Integration of perennial peanuts into warm-season grasslands offers a potential solution to reduce nitrogen (N) fertilizer input and enhance N cycling through soil microbial activities. There is limited information on the changes in soil microbial diversity and communities following the short-term integration of rhizoma perennial peanut (RPP; Arachis glabrata Benth.) into warm-season perennial bahiagrass (Paspalum notatum Flüggé) as well as its impact on N cycling processes. This study investigated changes in N cycling populations and soil microbial communities in bahiagrass-RPP mixtures compared to their monocultures at <2 years after RPP establishment in Spring (March) and Fall (October) seasons. Real-time qPCR was used to quantity N functional groups in the soil involved in nitrification, denitrification, and N₂ fixation. DNA amplicon sequencing was employed to examine co-occurrence networks of soil microbes, while activities of soil enzymes [N-Acetyl-β-d-glucosaminidase (NAG) and leucine aminopeptidase (LAP)] involved in N mineralization were also measured. Bahiagrass-RPP mixtures had no effect on N cycling genes. Ammonia oxidizing archaea were the major ammonia oxidizing prokaryotes compared to ammonia oxidizing bacteria in bahiagrass-RPP systems. We found that bahiagrass-RPP mixtures exhibited greater prokaryotic alpha diversity and NAG activities than RPP monoculture. Meanwhile, RPP influenced soil fungal community composition (beta diversity) and enhanced the relative abundance of dominant soil fungal genera (Fusarium, Gibberella, and Humicola). The presence of RPP in bahiagrass systems led to increased negative microbial interactions in microbial occurrence networks. Greater complexities in microbial networks were linked to forage growth season, which was related to enrichment of the relative abundance of Basidiomycota. Our findings showed that RPP has the potential to influence N cycling process in bahiagrass system by altering the abundance of certain N cycling microbes, especially fungal taxa, within 2 years of RPP establishment.

将多年生花生融入暖季草原提供了一种潜在的解决方案，可以减少氮肥输入并通过土壤微生物活动增强氮循环。关于根茎多年生花生（RPP； Arachis glabrata Benth.）短期融入暖季多年生百喜草（Paspalum notatum Flüggé）后土壤微生物多样性和群落的变化及其对氮循环的影响的信息有限流程。本研究调查了春季（三月）和秋季（十月）RPP 建立后不到 2 年的时间，与单一栽培相比，bahiagrass-RPP 混合物中氮循环种群和土壤微生物群落的变化。使用实时qPCR 来定量土壤中参与硝化、反硝化和N ₂固定的N 官能团。采用DNA扩增子测序来检查土壤微生物的共生网络，同时还测量了参与氮矿化的土壤酶[N-乙酰-β-d-氨基葡萄糖苷酶（NAG）和亮氨酸氨基肽酶（LAP）]的活性。Bahiagrass-RPP 混合物对氮循环基因没有影响。与 bahiagrass-RPP 系统中的氨氧化细菌相比，氨氧化古菌是主要的氨氧化原核生物。我们发现 bahiagrass-RPP 混合物比 RPP 单一培养表现出更大的原核 α 多样性和 NAG 活性。同时，RPP影响土壤真菌群落组成（β多样性）并提高土壤优势真菌属（镰刀菌属、赤霉属和腐质霉属）的相对丰度。bahiagrass 系统中 RPP 的存在导致微生物发生网络中负面微生物相互作用的增加。微生物网络的复杂性与饲料生长季节有关，这与担子菌门相对丰度的富集有关。我们的研究结果表明，在 RPP 建立的 2 年内，RPP 有可能通过改变某些氮循环微生物（特别是真菌类群）的丰度来影响 bahiagrass 系统中的氮循环过程。