Low legume-grass seeding ratio combined with phosphorus fertilization promotes forage yield and soil quality in managed grasslands

Forage yield of 4 monocultures and 5 legume-grass mixtures at 3 study sites over 5 years, Cangzhou, Taiyian and Yinchuan, and soil quality parameters were included in this dataset. Legume and grass seeds were combined into one of five different legume:grass mixtures of 3:7, 4:6, 5:5, 6:4, or 7:3, and each legume:grass ratio received P fertilization at a rate of 0, 9, 18, or 27 kg P ha^-1 year^-1. Forage yield of each plant community was measured at the initial flowering stage of alfalfa and all plants were mowed at 5 cm above ground by species, dried in an oven (65 ◦C, 48 h), and weighed. Soil sampling was collected to measure soil organic matter, total nitrogen, plant-available phosphorus, pH value, soil ezymatic activity and microbial biomass. Our results showed legume-grass mixture at seeding ratio of 3:7 with moderate P fertilization of 18 kg P ha^-1 year^-1 resulted in the highest forage yield among all monocultures and mixtures, for each of the three sites, with persistent and consistent transgressive overyielding. Moreover, significantly greater soil organic matter, total nitrogen, enzymatic activity, and microbial biomass were also observed in the 3:7 mixture, compared with monoculture or other seeding ratios.The file named as Forage yield at 3 sites supplied total forage yield of 4 monocultures and 5 legume-grass mixtures at each of study sites, Cangzhou, Taiyuan and Yinchuan, over 2016-2020. <i>Ms</i>, <i>Ov</i>, <i>Dg</i>, and <i>Fa</i> mean monoculture of alfalfa, sainfoin, orchardgrass and tall fescue, respectively. LG means legume-grass seeding ratio. P0, P1, P2 and P3 mean phosphorus fertilization rate of 0, 9, 18, or 27 kg P ha^-1 year^-1. The file named as Soil quality parameters supplied the results of soil nutrient, enzymatic activities, and microbial variables. MM means the treatment of mean monoculture. Best means the treatment of the best-performed monoculture. SOM, soil organic matter; TN, total nitrogen; AP, plant-available phosphorus; pH, pH-value; ACP, acid phosphatase; NR, nitrate reductase; UR, urease; SU, sucrose; MBC, soil microbial carbon; MBN, soil microbial nitrogen; PLFAs, phospholipid fatty acids; bacteria, bacterial PLFA; fungi, fungal PLFA.

本数据集涵盖沧州、太原、银川三个试验站点为期5年的4种单作群落与5种豆科-禾本科混播群落的牧草产量数据，同时包含土壤质量参数。
豆科与禾本科种子按5种不同播混比例（3:7、4:6、5:5、6:4或7:3）进行组合，且每种播混比例的群落均施加0、9、18或27 kg P·ha⁻¹·a⁻¹的磷肥。
各植物群落的牧草产量于苜蓿初花期测定：所有植物均按物种以5 cm的地上高度进行刈割，随后置于65 ℃烘箱中烘干48小时后称重。
本数据集采集土壤样品以测定土壤有机质（soil organic matter）、全氮、有效磷（plant-available phosphorus）、pH值、土壤酶活性及微生物生物量。
研究结果表明，在三个试验站点中，播混比例为3:7且施加中等用量磷肥（18 kg P·ha⁻¹·a⁻¹）的豆科-禾本科混播群落，在所有单作与混播处理中牧草产量最高，且表现出持续且稳定的超产效应。此外，与单作群落或其他混播比例相比，该3:7混播处理的土壤有机质、全氮、酶活性及微生物生物量均显著提升。
名为《三站点牧草产量》的文件包含了2016-2020年间沧州、太原、银川三个试验站点的4种单作群落与5种豆科-禾本科混播群落的总牧草产量数据。其中Ms、Ov、Dg和Fa分别代表苜蓿（Alfalfa）、红豆草（Sainfoin）、鸭茅（Orchardgrass）和高羊茅（Tall Fescue）的单作处理；LG代表豆科-禾本科混播比例；P0、P1、P2和P3分别代表磷肥施用量为0、9、18和27 kg P·ha⁻¹·a⁻¹的处理。
名为《土壤质量参数》的文件包含了土壤养分、酶活性及微生物相关指标的测定结果。其中MM代表单作群落平均值处理，Best代表表现最优的单作处理。相关指标缩写及对应全称如下：SOM（soil organic matter，土壤有机质）、TN（total nitrogen，全氮）、AP（plant-available phosphorus，有效磷）、pH（pH值）、ACP（acid phosphatase，酸性磷酸酶）、NR（nitrate reductase，硝酸还原酶）、UR（urease，脲酶）、SU（sucrose，蔗糖酶）、MBC（soil microbial carbon，土壤微生物碳）、MBN（soil microbial nitrogen，土壤微生物氮）、PLFAs（phospholipid fatty acids，磷脂脂肪酸）、bacteria（bacterial PLFA，细菌磷脂脂肪酸）、fungi（fungal PLFA，真菌磷脂脂肪酸）。