接种根瘤菌对苜蓿生长及土壤养分的影响

摘要

To investigate the effects of rhizobium on the growth of alfalfa,the plant height,above-ground biomass,branch number,root nodule number and weight of three alfalfa varieties (Medicago sati-va L.cv.Aohan,M .varia Martin.cv.Caoyuan No.3,M .sativa L.)were measured at different stages (30,60,90 and 120 days)after infection of three types of rhizobium (CK,Dormal and Bendijun).Soil pH,total nitrogen,sulfur (S),available nitrogen,available phosphorus,available potassium (K)content were determined to analyze the changes in soil nutrients under different treatments for 120 days.The re-sults showed that there was no significantly difference in above-ground biomass among the three alfalfa va-rieties at early stages (30~90 days),while the above-ground biomass of two cultivated varieties were sig-nificantly higher than the native variety (M .sativa L.cv.Aohan)at late stages (90 ~ 120 days ). Through the entire growing season,all three alfalfa varieties inoculated with Bendijun grew better than that inoculated with Dormal.Furthermore,it was found that soil available N and decreased soil available K and total S content increased after cultivating alfalfa.%选取3个苜蓿品种(敖汉苜蓿、草原3号杂花苜蓿、德国苜蓿)接种不同根瘤菌剂(多萌和本地菌),分别测定植株生长当年第30d、60d、90d、120d 的株高、地上生物量、分枝数、有效根瘤数量和重量等指标,同时测定生长120d 后土壤各常规养分(全氮,速效氮、磷、钾和硫元素等)含量,比较不同接种条件下3个苜蓿品种的生长差异与土壤养分的变化。结果表明,3个苜蓿品种生长初期(30~90d)地上生物量无显著差异,2个育成品种(草原3号杂花苜蓿、德国苜蓿)生长后期(90~120d)的地上生物量显著高于地方品种(敖汉苜蓿)；在整个生长周期内,接种本地菌的3个品种生长状况与结瘤效果均优于接种多萌；种植苜蓿后土壤速效氮含量增加,土壤中速效钾和硫元素含量降低。