稀土对豆科牧草根瘤菌生长和应用效果的研究

STUDIES ON THE EFFECT OF RARE ELEMENT ON GROWTH AND APPLICATION ON RHIZOBIA OF FORAGE LEGUMES

试验在液体和固体培养下观测了稀土对苜蓿根瘤菌、红三叶根瘤菌、自三叶根瘤菌和沙打旺根瘤菌生殖的影响和田间应用效果。结果表明,稀土浓度在100～300ppm时,4种根瘤菌菌数增多,植株鲜重,植株根瘤鲜重和根瘤的固氮活性等均明显增高,表明有促进效应。液体培养下,当稀土浓度为500ppm时,4种根瘤菌菌数的增殖受到抑制;稀土浓度达1,000ppm时,四种根瘤菌均不生长。但是在固体培养下稀土对它们的生长仍具有促进效应。稀土与牧草根瘤菌配合施用,对豆科牧草植株鲜重和根瘤鲜重均显著增高,且根瘤的固氮活性比对照增加0.22～3.27倍。田间试验下四种豆科牧草株高平均增高35.9±3.5％,干草产量平均较对照增产34.9±3.4％。

Four Rhizobia (Rh.Meliloti, Rh.Trifolium pratense, Rh.Trifolium repens and Rh.Astragalus adsurgens) have been studies for measured their growth and application with rare element under liquid and solid medium and field experiments.The results showed that the cells of four Rhizobia were increased; the fresh weight of plants and root nodes and their nitrogen fixation activity were promoted under 100—300 ppm rare element.It has been inhibited to incresse cell of Rhizobia under liquid medium with 500 ppm rare element and the cell of four Rhizobia was stoped growth under 1000 ppm rare element.But they have been still promoted under solid condition.Under mixing rare element with Rhizobia the fresh weight of forage legumes plants and their root nodes were increased significantly and the nitrogen fixation activity of root nodes were increased 0.22—3.27 times than control.The mean heights of four forage legumes were increased 35.9±3.5% and mean yields of dry matter of four forage legumes plants were increased 34.9±3.4%.