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Titre : Research on Rhizosphere Soil Properties of Salix Psammophila Forests in Hobq Desert

Auteur : 王涛

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé partiel
Salix psammophila,the most widely distributed species in the Kubuqi Desert,is an excellent windbreak and sand-fixing tree species in the Kubuqi Desert.By analyzing the differences in soil nutrients,enzyme activities and microbial numbers between the rhizosphere and non-rhizosphere soils of Salix psammophila forests of different ages in the Kubuqi Desert,and their rhizosphere effects,the adaptation and improvement mechanisms of Salix psammophila forests and soils were clarified.The main conclusions obtained are as follows :（1）The physical and chemical properties of the rhizosphere soil of the Salix psammophila with different ages showed obvious layering characteristics,from high to low,0-10cm＞10-20cm＞20-30cm＞30-40cm＞40-50cm,in contrast The physical and chemical properties of the topsoil were more obvious.In the horizontal direction,the physical and chemical properties of rhizosphere and non-rhizosphere soils showed significant differences in 15a,and soil water content,organic carbon,alkali-hydrolyzed nitrogen,total nitrogen,available phosphorus,total phosphorus,available potassium and total potassium content increased by 3.1%,18.1%,11.4%,73.8%,7.4%,171.2%,10.6%and 9.2%.The rhizosphere effect coefficients of p H,available phosphorus,total nitrogen,and total potassium were the largest in the soil at 3a ;soil water content,organic carbon,and available potassium were the largest in the soil at 9a ;alkaline hydrolyzable nitrogen and total phosphorus were in the soil at 15a.The inter-effect coefficient is the largest.（2）There is no certain regularity in the changes of soil enzyme activities and microbial numbers in the rhizosphere of Salix psammophila with different stand ages.The rhizosphere effects of invertase and catalase are more obvious than those of other soil enzymes,and the rhizosphere effects of bacteria and actinomycetes are higher than those of other soil enzymes.Fungus is evident.Among them,the rhizosphere and non-rhizosphere maximum values of soil invertase and catalase were 27.29μg·kg-1·d-1and 15.24μg·kg-1·d-1 and 20.51μmol·kg-1·d-1,respectively.and 19.91μmol·kg-1·d-1.（3）Correlation analysis showed that sucrase,alkaline phosphatase and catalase had greater correlation with rhizosphere soil physicochemical indexes,while urease had greater correlation with non-rhizosphere soil physicochemical indexes.In the Salix psammophila forests soil of 9a,the correlation between the number of actinomycetes and the physicochemical properties of non-rhizosphere soil was high.In the 15-year-old Salix psammophila forests soil,the number of bacteria was highly correlated with the physical and chemical properties of the rhizosphere and non-rhizosphere soils.The number of soil microorganisms in the rhizosphere was significantly correlated with urease and sucrase,while the number of microorganisms in the non-rhizosphere soil was only significantly correlated with alkaline phosphatase and catalase.（4）Comprehensive analysis showed that the rhizosphere soil’s various soil property indexes were always higher than those of non-rhizosphere soil,and the rhizosphere effect of soil physical and chemical properties was more obvious than that of soil enzyme activity and soil microbial quantity.It shows that the rhizosphere soil has a certain aggregation effect,among which the soil physical and chemical properties are more significant

Mots clés : Hobq Desert ;Salix psammophila ;Rhizosphere effect ;Soil physical and chemical properties ;Soil microorganisms ;

Présentation (CNKI)