Abstract: Three treatments of inoculation with rhizobium (IR),inoculation with rhizobium + application of NPK compound fertilizer at the re-greening stage (IR+AF),and no inoculation with rhizobium + no fertilization (CK) were set up in the underwood planting red clover (Trifolium pratense) in the woodland,and the growth phenotype,nodule quantity,forage yield and nutrient quality at early flowering stage of red clover,and the soil characteristics were studied in this research. The results showed that both IR and IR+AF treatments could promote the plant growth,improve the forage yield and nutritional quality of the underwood planting red clover in the forest. Especially,the plant height,stem diameter,leaf length and leaf width of red clover at initial flowering stage under IR+AF combined treatment increased by 18.70%,19.39%,8.96% and 6.98% compared with those in CK,respectively. The Ash,CP and EE contents were increased by 22.67%,13.46% and 17.78%,the ADF and NDF contents were significantly decreased by 16.22% and 14.57%,and the RFV was significantly increased by 28.29% compared with that in CK,respectively. IR treatment was beneficial to promote the root growth of red clove and the total number of effective nodules of the roots reached 92.33 per plant,which was 1.94 times that of CK. Both IR and IR+AF treatments had positive effects on the contents of soil organic matter,alkali-hydrolyzed nitrogen and available phosphorus. In particular,the soil organic matter content in 0~10 cm and 10~20 cm at IR+AF treatment were significantly increased by 41.28% and 35.59%,and the content of available phosphorus were increased by 12.50% and 51.75%,compared with those in CK. These results could provide scientific basis and technical support for the efficient cultivation and management of red clover under forest.

Key words: Combination of forest and grass, Trifolium pratense, Rhizobium, Yield and quality, Soil physicochemical properties

摘要： 本试验设置接种根瘤菌(IR)、接种根瘤菌+次年返青追施氮磷钾复合肥(IR+AF)和不接种根瘤菌+不施肥(对照组CK)三种处理，对林下红三叶(Trifolium pratense)的生长表型、结瘤数量、初花期草产量和营养品质及土壤特性进行研究。结果表明，IR和IR+AF处理均可促进林下红三叶植株生长，提高草产量和营养品质，特别是IR+AF复合处理下的初花期红三叶株高、茎粗、叶长和叶宽分别较CK增加18.70%,19.39%,8.96%和6.98%，粗灰分、粗蛋白和粗脂肪含量分别较CK提高22.67%,13.46%和17.78%，酸性洗涤纤维和中性洗涤纤维含量分别较CK显著降低16.22%和14.57%，相对饲喂价值显著增加28.29%；IR单一处理利于促进初花期植株根系结瘤，有效结瘤总数达92.33个·株^-1，是CK的1.94倍；IR和IR+AF处理均对土壤有机质、碱解氮和速效磷含量具有正向促进作用，特别是IR+AF处理下0~10 cm和10~20 cm土壤有机质含量较CK显著增加41.28%和35.59%，土壤速效磷含量增加12.50%和51.75%，本结果为林下红三叶高效栽培提供科学依据和技术支撑。

关键词: 林草复合, 红三叶, 根瘤菌, 产量与品质, 土壤理化性质