施肥和苜蓿接种根瘤菌对苜蓿生长及铁尾矿砂基质理化性质的影响

Effects of fertilizer and Rhizobium inoculation on alfalfa growth on mine tailings and the physicochemical properties of iron tailings

本研究采用室外盆栽的方式,探讨了施肥水平和苜蓿接种不同根瘤菌菌株对紫花苜蓿生长及铁尾矿砂基质理化性质的影响。结果表明,接种根瘤菌可显著促进紫花苜蓿株高、根长、地上鲜重、根鲜重、总生物量和瘤鲜重的增加,其中以接种菌株17676的效果最佳。而接种根瘤菌的苜蓿在种植当年对铁尾矿砂基质理化性质的改善有一定的促进作用,但效果不显著。施肥明显促进了苜蓿生长,随着施肥水平的提高,苜蓿株高、根长、地上鲜重、根鲜重和总生物量逐渐增大,在N3施肥水平时最高,并且N3施肥水平条件下的株高、地上部鲜重和总生物量与N2和N1两个施肥水平间差异显著。在促进根瘤重的增加方面,N2施肥水平效果最好,但与N3水平间差异不显著。在改良铁尾矿砂理化性质方面,施肥不仅能明显促进铁尾矿砂容重和pH值的降低,还能显著促进其田间持水量、总孔隙度以及有机质、碱解氮、速效磷和速效钾含量的增加。在降低容重、酸碱度以及提高有机质、速效磷和速效钾含量方面,N3施肥水平的效果均明显优于N1和N2水平。

This study was undertaken to determine the effects of fertilizer application (iron tailings and organic fertilizer)and Rhizobium inoculation with different strains on the growth of alfalfa planted in iron mine tailings and the physicochemical properties of the soil-plant system in outdoor pots.Rhizobium inoculation significantly increased height growth,root growth,above ground fresh weight,root fresh weight,total biomass and fresh nodule weight.The most effective Rhizobium was strain No.17676.Inoculated alfalfa also influenced the phys-icochemical properties of iron mine tailings,but the effect was not significant in the first year of the study.Fer-tilizer application markedly promoted alfalfa growth.Increasing fertilizer rates increased plant height,above ground fresh weight and total biomass.The N2 fertilizer treatment produced the greatest increase in root noduleweight.Fertilizer application significantly reduced soil bulk density and pH but increased organic matter,avail-able nitrogen,available phosphorus,and available potassium in the mine tailings soil.These effects were sig-nificantly higher for the N3 treatment compared to lower fertilizer rates.