黄土丘陵区不同植被对根际土壤微生物特性的影响

为了解黄土高原植被恢复对根际土壤微生物特性的影响,以黄土丘陵区墩山小流域的6种植被为研究对象,分析了不同植被根际、非根际土壤有机碳、微生物量C、微生物量N、基础呼吸以及酶活性的变化趋势。结果表明:6种植被中,柠条(Caragana korshinskii)、阿尔泰狗娃花(Heteropappus altaicus)和茵陈蒿(Artemisia capillaris)根际土壤有机碳高于非根际;沙打旺(Astragalus adsurgens)、柳枝稷(Panicum virgatum)、阿尔泰狗娃花和茵陈蒿根际pH值均低于非根际;除沙棘(Hippophae rhamnoides)外,其他植被的根际微生物量N高于非根际;沙棘、阿尔泰狗娃花和茵陈蒿根际土壤微生物量C高于非根际;6种植被的根际基础呼吸和过氧化物酶显著高于非根际(P<0.05),多酚氧化酶两者无显著差异,蔗糖酶、脲酶、碱性磷酸酶及过氧化氢酶变化趋势不同。根际与非根际土壤有机碳、微生物量C、微生物量N、蔗糖酶、脲酶和过氧化氢酶之间呈极显著正相关(P<0.01),过氧化物酶与基础呼吸呈显著正相关(P<0.05),与多酚氧化酶呈极显著负相关(P<0.01)。无论是根际土壤还是非根际土壤,天然草地(阿尔泰狗娃花和茵陈蒿)的有机碳、微生物量C、微生物量N、蔗糖酶、脲酶、过氧化氢酶及过氧化物酶总体高于人工灌木(柠条和沙棘)和人工草地(沙打旺和茵陈蒿)。

Effects of Different Vegetation on Rhizosphere Soil Microbial Properties in the Hilly-Gully Region of Loess Plateau

In order to explore the effect of revegetation on rhizosphere soil microbial properties in Loess Plateau,the changes of organic carbon (C),microbial biomass C,microbial biomass N,basal respiration and enzymes activities in both rhizosphere and bulk soil of six vegetation types at the Dunshan watershed of Hilly-Gully Region were investigated.Results showed organic C in the rhizosphere soil of Caragana korshinskii,Heteropappus altaicus and Artemisia capillaris was higher than that in bulk soil.The pH in the rhizosphere soil of Astragalus adsurgens,Panicum virgatum,Heteropappus altaicus and Artemisia capillaris was lower than that in bulk soil.With an exception of Hippophae rhamnoides,microbial biomass N in rhizosphere soil of five vegetation types was higher than that in bulk soil.Microbial biomass C in the rhizosphere of Hippophae rhamnoides,Heteropappus altaicus and Artemisia capillaris was higher compared with in bulk soil.All plants showed higher basal respiration and peroxidase in the rhizosphere soil than that in bulk soil.Saccharase,urease,alkaline phophatase and catalase had different change tendency in rhizosphere and bulk soil.Rhizosphere did not have significant effect on polyphenol oxidase.There were positively correlation between soil organic C,microbial biomass C,microbial biomass N,saccharase,urease and catalase.Peroxidase was positively correlated with basal respiration but negatively with polyphenol oxidase.Furthermore,natural grassland (Heteropappus altaicus,Artemisia capillaris) showed higher organic C,microbial biomass N,saccharase,urease,catalase and polyphenol oxidase in the both rhizosphere and bulk soil than artificial shrubland (Caragana korshinskii,Hippophae rhamnoides) and artificial grassland (Astragalus adsurgens,Panicum virgatum).