Microbes,Enzyme Activities And Nutrient Characteristics Of Rhizosphere And Non-Rhizosphere Soils In The Loess Plateau

In this study,9 types of forests(Hippophae rhamnoides,Robinia pseudoacacia,Pinus tabulaeformis,Populus simonii,Quercus wutaishanicaa,Betula platyphylla,Platycladus orientalis,Larix gmelinii and Lespedeza bicolor)were chosen to measure microbial abundance,enzyme activities and nutrient characteristics of rhizosphere and non-rhizosphere soils to make a comprehensive comparison of the soil fertility between rhizosphere and non-rhizosphere soils.The abundance of soil bacteria,fungi and actinomycetes,the activities of catalase,polyphenol oxidase and urease,soil organic matter(SOM),total nitrogen(N),total phosphorus(P),total potassium(K),alkai-hydrolyzadle N,available P and available K were determined and One-way analysis of variance and analysis of correlation were conducted.The results indicated that:1)the differences of the contents of SOM,available P,alkali-hydrolyzadle N and available K between rhizosphere and non-rhizosphere soils were significant(P<0.05).SOM and available nutrients accumulated in rhizosphere soil.2)Microbial abundance and enzyme activities of rhizosphere soil were generally higher than non-rhizosphere soil.With exceptions,catalase activity in Pinus tabulaeformis and urease activity in Hippophae rhamnoides were lower in rhizosphere soil than non-rhizosphere soil.3)There was a significant correlation between catalase activity and abundance of soil bacteria,actinomycetes and fungi.There was a significant correlation between polyphenol oxidase and abundance of soil actinomycetes and fungi.There was also a significant correlation between urease and abundance of soil bacteria and fungi.SOM was significantly correlated with the abundance of soil bacteria and actinomycetic,and urease activity.The soil available P and alkai-hydrolyzadle N contents were significantly correlated with urease activity,and the abundance of soil bacteria and fungi.In non-rhizosphere soil,the correlation of the contents of soil nutrients with soil microbial abundance and soil enzyme activities was lower than that in rhizosphere soil.4)The comprehensive fertility level of the rhizosphere soil was higher than that of the non-rhizosphere soil.The fertility level of rhizosphere soil followed the order:Hippophae rhamnoides>Quercus wutaishanica>Populus simonii>Betula platyphylla>Larix gmelinii>Pinus tabulaeformis>Robinia pseudoacacia>Platycladus orientalis.The growth of Hippophae rhamnoides and Quercus wutaishanica can improve soil fertility more effectively than the other species.Hippophae rhamnoides and Quercus wutaishanica is suitable for afforestation to help improve soil fertility and make contributions to revegetation.