丛枝菌根真菌对羊草生物量和氮磷吸收及土壤碳的影响

采用大田试验的方法在内蒙古锡林格勒草原进行牧草接种试验,通过灭菌和未灭菌两种土壤研究接种丛枝菌根真菌Glomus mosseae和Glomus claroidium对内蒙古典型草原优势种羊草生长的影响.结果显示,接种丛枝菌根真菌对羊草的地上部干重未产生显著影响,但向未灭菌土壤中接种能显著增加羊草根系量,同时接种G.mosseae显著增加了地上部的N、P含量及吸收量,有效地改善了植株N、P营养,提高了牧草品质;2种菌对根系的营养吸收影响不同,接种G.mosseae在灭菌土壤和未灭菌土壤中均能显著增加根系的N、P吸收量,而接种G.claroidium仅在土壤未灭菌状态下增加根系N、P吸收量;接种对土壤中的菌丝密度未产生显著影响,但接种后土壤中微生物量碳有增加的趋势,短期内难以观察到接种对土壤有机碳的影响.研究表明,丛枝菌根真菌能够提高牧草对N、P吸收,促进牧草的生长,改善牧草品质,增强牧草根际微生物量碳.

Effects of Arbuscular Mycorrhizal Fungi on Leymus chinensis Growth and Soil Carbon

The grass with inoculation in field trial was conducted in Xilingele grassland in Inner Mongolia,which studied the effects of Glomus mosseae and Glomus claroidium on growth of Leymus chinensis,a dominant species in Inner Mongolia steppe,with or without soil sterilization treatments.The results showed that there was no significant impact on the shoot biomass of L.chinensis with arbuscular mycorrhizal fungi.However,inoculation in non-sterilized soil significantly increased L.chinensis roots biomass.And G.mosseae inoculation significantly increased the plant aboveground N,P content and uptake,efficiently improved the plant N and P nutrition and forage quality.Two kinds of fungal inoculums had different effects on root nutrient absorption.G.mosseae significantly increased N,P of root uptake both in sterilized and natural soil.G.claroidium only increased N,P of root uptake in non-sterilized soil.There was no significant impact on hyphal length density with inoculation.However,there was an increasing trend for microbial biomass carbon in soil after inoculation.And it was difficult to observe the impact on soil organic carbon with inoculation in a short term.Therefore,arbuscular mycorrhizal fungi could improve the grass N,P uptake,promote growth and forage quality,and boost up microbial biomass carbon in soil.