中文摘要：

从岷山红三叶根际分离出高效溶磷菌，并对其分泌生长激素、拮抗病原菌特性进行测定，筛选出优良促生菌6株，根瘤菌1株，按照一定比例混合制成复合菌肥，进行盆栽试验，研究复合菌肥对岷山红三叶产量、品质及异黄酮含量的影响。结果表明：利用筛选的优良促生菌和根瘤菌研制的复合微生物菌肥符合《微生物肥料》标准（NY227-94）。75％化肥＋PGPR菌肥处理使岷山红三叶干草总产量较 CK 增加4．76％，同时，该处理可提高红三叶粗蛋白、粗灰分、钙、磷含量，降低中、酸性洗涤纤维含量；50％化肥＋PGPR菌肥处理对岷山红三叶的总干草产量、营养品质以及4种异黄酮的含量均没有显著影响。

英文摘要：

Interest in plant growth promoting rhizobacteria （PGPR）has increased due to their potential contri-bution to sustainable agricultural systems by reducing environmental impact,the consumption of non-renew-able resources and input costs.This paper investigates the inoculant effect of PGPR on the hay yield and nutri-ent quality of Trifoliumpratensecv.Minshan.Six PGPR and one rhizobia strains were identified by screening for phosphate solubilization,3-indoleacetic acid （IAA）secretion and antagonism to plant pathogens.A PGPR inoculant was produced by mixing these strains and pot tests have been conducted to investigate its effects on the growth and quality of T.pratensecv.Minshan when combined with different amounts of chemical fertiliz-er.The results showed that the nitrogenase activity of the rhizobia strain was 488.2 C2 H4 nmol/（mL＆#183;h）.The phosphate solubilization and IAA secreting ability of the five PGPR strains was distributed across the ranges 50.34-229.5 mg/L and 0.86-12.01 μg/mL respectively.The PGPR compound bio-fertilizer demonstrated strong antagonism to the pathogensFusariumoxysporium f.sp.cucumerinum,RhizoctoniasolaniandFusar-iumoxysporum f.niveum.The composite microbial inoculant complies with the quality standard for microbio-logical fertilizer in China （NY227-94）.Applying the inoculant in combination with 75%of the control’s chemi-cal fertilizers increased total hay yield by 4.76%.Nutrient quality also improved.The amount of crude pro-tein,crude ash,calcium and phosphorus increased while the amount of neutral detergent fiber and acid deter-gent fiber declined.Applying the inoculant in combination with 50% of the control’s chemical fertilizers did not increase total hay yield,quality,or the isoflavone content of clover.The experiment has thus shown how the PGPR compound bio-fertilizer can be combined with chemical fertilizers to increase not only the yield and quality of T.pratensecv.Minshan but also the sustainability of agricultural systems.