Soil drainage and phosphorus (P) availability are considered indicators of management intensity in pasture-based agriculture supporting livestock. However, microbial adaptations to P-availability according to soil drainage class are rarely investigated. We hypothesized that well-drained grasslands with high P-availability will sustain a distinctive soil microbiota when compared to poorly-drained grasslands with low-P availability. The relationship between soil drainage, plant available P and grassland microbial communities was evaluated among well-drained sites with high- or low-P and poorly-drained sites with high- or low-P, using fingerprinting, next-generation sequencing and quantitative PCR. Bacterial community structures were primarily affected by drainage as well as significantly separated between a combination of drainage and P availability i.e. low-P and poorly drained versus high-P and well drained. Abundance of the bacterial phylum Actinobacteria was significantly higher in well-drained high-P soils while Firmicutes were more abundant in well-drained low-P soils. Soil fungal communities responded to both drainage status and plant available P. Fungal phyla such as Basidiomycota responded strongly towards availability of P, while Glomeromycota were most abundant in poorly drained low-P soils. The diversity of the alkaline phosphatase gene phoD responded more clearly to drainage than availability of P. Of the other environmental factors, soil pH significantly affected the bacterial and fungal communities structure analyzed. This study suggests that while bacteria and fungi are affected by a combination of soil drainage and P availability in Irish grassland soils, drainage has a more profound influence on bacterial communities than P availability.

在以畜牧业为基础的以牧场为基础的农业中，土壤排水和磷的有效性被认为是管理强度的指标。但是，很少根据土壤排水类别研究微生物对磷有效性的适应性。我们假设，与低磷可利用的低排水草原相比，高磷可利用的高排水草原将维持独特的土壤微生物区系。使用指纹图谱，下一代测序和定量PCR评估了高磷或低磷高排水地点和高磷或低磷低排水地点土壤排水，植物有效磷与草地微生物群落之间的关系。 。细菌群落结构主要受到排水的影响，以及排水和磷有效性之间的显着分离，即低磷和排水不良与高磷和排水良好。排水良好的高磷土壤中细菌门放线菌的丰度明显更高，而排水良好的低磷土壤中的菌丝菌则更为丰富。土壤真菌群落对排水状态和植物有效磷都有反应。真菌门类（如担子菌）对磷的有效性有很强的响应，而引流菌在排水不良的低磷土壤中含量最高。碱性磷酸酶基因的多样性 排水良好的高磷土壤中细菌门放线菌的丰度明显更高，而排水良好的低磷土壤中的菌丝菌则更为丰富。土壤真菌群落对排水状态和植物有效磷都有反应。真菌门类（如担子菌）对磷的有效性有很强的响应，而引流菌在排水不良的低磷土壤中含量最高。碱性磷酸酶基因的多样性 排水良好的高磷土壤中细菌门放线菌的丰度明显更高，而排水良好的低磷土壤中的菌丝菌则更为丰富。土壤真菌群落对排水状态和植物有效磷都有反应。真菌门类（如担子菌）对磷的有效性有很强的响应，而引流菌在排水不良的低磷土壤中含量最高。碱性磷酸酶基因的多样性phoD对排水的响应比对P的响应更清楚。在其他环境因素中，土壤pH值显着影响所分析的细菌和真菌群落结构。这项研究表明，尽管细菌和真菌受爱尔兰草原土壤中土壤排泄和磷有效性的综合影响，但排水对细菌群落的影响远大于磷的有效性。