Abstract:

The properties and changes of rhizosphere soil nutrient were studied at three different sites dominated by Salix gordejevii,Artemisia halodendron and Caragana microphilla,respectively,in Horqin sandy land.Results showed that rhizosphere imposed obvious effects on the three shrubs and soil nutrition.The pH value in rhizosphere soil of the shrubs was lower than that in the non-rhizosphere,but the significance was not obviously.And the electric conductivity of the rhizosphere soil was obviously higher than non-rhizosphere soil in August,although electric conductivity was lower in the rhizosphere than non-rhizoshphere in May.Electric conductivity in C.microphylla rhizosphere was consistently higher,either in May or in August.The organic matter content and material content of three shrubs were all higher in rhizosphere than those in non-rhizosphere soil in May and August,except organic matter and total N in rhizosphere of S.gordejevii in May.Three shrubs have obviously positive rhizosphere effects on soil nutrient and the order of ability is C.microphilla > A.halodendron> S.gordejevii.By comparing rhizosphere nutrients of three shrubs in May and August,the organic matter content and material content of S.gordejevii all increased in August,especially total N and available P were two times higher than those in May.The content of total N and organic matter content in rhizosphere of C.microphylla in August was higher than those in May,but other nutrient clearly decreased during the growth period.Rhizosphere nutrients of A.halodendron experienced the same changes,except that total P in August.

Key words: shrubs, rhizosphere soil nutrients, pH, electric conductivity, Horqin sandy land