Microbes, enzyme activities and nutrient characteristics of rhizosphere and non-rhizosphere soils under four shrubs in Xining Nanshan, Prefecture, China

Abstract

Afforestation is the most effective method of revegetation and choosing suitable afforestation tree species is regarded as a key performance criterion. In this study, 4 shrub species ( Nitraria tangutorum, Caragana korshinskii, Berberis vernae and Caragana brevifolia, planted in Xining Nanshan, Prefecture, China in 2009) were studied to measure microbial abundance, enzyme activities and nutrient characteristics of rhizosphere and non鄄rhizosphere soils. The variables measured included abundance of soil bacteria, fungi and actinomycetes, catalase activity, acid phosphatase activity, urease activity, pH, organic matter ( OM ) , total nitrogen ( N) , total phosphorus ( P ) , total potassium ( K) , hydrolysis N, available P and available K. The effects of shrubs on soil properties were evaluated by making a comprehensive comparison http: / / www.ecologica.cn of the soil fertility of rhizosphere and non鄄rhizosphere soils. The results showed: 1) Microbial abundance and enzyme activities of rhizosphere soil were generally higher than non鄄rhizosphere soil except for the abundance of actinomycetes and urease activity. Specifically, only the total microbial abundance of rhizosphere soil under N. tangutorum was less than that of non鄄rhizosphere soil, and urease activity in rhizosphere soils under all 4 shrubs were lower than their non鄄rhizosphere soils; 2) Soil pH, N, P and total K contents of rhizosphere and non鄄rhizosphere soils were not significantly different. OM, P and available K of rhizosphere soils were significantly higher than non鄄rhizosphere soils, whereas available N was higher in non鄄rhizosphere than rhizosphere soils. These results showed that the presence of the 4 shrubs could improve soil OM, available P and available K contents through root aggregation; 3) There was no significant correlation between soil enzyme activities and soil microbial abundance, OM was significantly correlated with soil bacterial and fungal abundance, and soil available P content was significantly correlated with abundance of soil bacteria, fungi and actinomycetes. The soil available P content was significantly correlated with soil catalase and acid phosphatase activities and the soil total N and available N were significantly positively correlated with urease activity. From these results, the correlation between soil nutrients and enzyme activities differed from the correlation between soil nutrients and microbial abundance, thus soil enzyme activities and microbial abundance were proven to have a significant influence on soil nutrients; 4) The results of principal component analysis showed that soil bacterial abundance, fungal abundance, catalase activity, acid phosphatase activity, pH, OM, total N, total K and available P contents showed high factor loadings and these indexes could provide important information on soil fertility. In addition, principal component factor scores and synthetic scores of soil fertility levels showed that soil fertility of rhizosphere soils was significantly higher than non鄄rhizosphere soils. It showed t...

Microbial Assemblages Associated with the Soil-Root Continuum of an Endangered Plant, Helianthemum songaricum Schrenk

“…These data suggested that despite many differences in growth environments, host genetics, and plant development, the soil and roots of shrubs recruited and maintain many similar microbial taxa ( 41 ). These bacteria could play a vital part in the ecology of Helianthemum songaricum and other shrubs, and they also play a dominant role ( 42 ). A previous study also reported that both Actinobacteria and Acidobacteria were the main bacterial groups in the root and soil communities of shrub plants ( 43 ).…”

Effect of Karst Microhabitats on the Structure and Function of the Rhizosphere Soil Microbial Community of Rhododendron pudingense

“…Due to the influence of plant root exudates, its physical and chemical properties and biological activities are different from those of the original soil [7]. In recent years, the rhizosphere has received extensive attention, and many scholars take the rhizosphere soil as the research object to reveal the interaction between plant, environment and microbes [8,9]. In different environment conditions, microbial communities can affect the decomposition and utilization of organic matter by changing various metabolic properties [10].…”