Effect Of Several Phosphate-solubilizing Microbial Agents On Properties Of Alkaline Soil In Lanzhou North Mountains

The alkaline soil by farmland surface in Lanzhou North Mountains was selectedfor the test soil, and the effects of eight phosphate-solubilizing microbial agents (fourorganic phosphate-solubilizing microorganism and four inorganicphosphate-solubilizing microorganism) on soil biology, physics, chemical propertiesof alkaline soil and vegetable (Brassica chinensis var. chinensis) growth, soil fertilityquality was studied by pot experiment.15indexes and the method of VarianceAnalysis, Correlation Analysis, Principal Component Analyses and Cluster Analysiswere used to evaluate soil property, fertility quality and type. The results are asfollows:1. The result indicates that change on vegetable growth indexes, soil biology,physics and chemical properties by applying eight phosphate-solubilizing microbialagents on alkaline soil. There can increase on vegetable growth and development,improve chlorophyll, leaf quantity, height and dry matter on aerial parts of vegetable.And the amount of soil microorganism, nutritional ingredient and soil enzymeactivities are increase. It were fit to vegetable growth by improve physical structureand chemical properties by applying phosphate-solubilizing microbial agents onalkaline soil in study.2. The relationship among15indexes was studied by simple CorrelationAnalysis; the result shows that existence of a certain relationship between theevaluation indexes. And six indicators have greater effect on others, there werealkaline phosphates activity represents soil enzyme activity, organic matter representssoil fertility, bulk density and10℃permeability represent soil physical structure,cation exchange capacity represents soil fertilizer capacity, solubility Ca2+representssoil ion concentration. And the result indicates that pH of alkaline soil decrease while10℃hydraulic conductivity and the concentration of solubility Ca2+increasesignificantly, the amount of soil microorganism and enzyme activities wereamelioration. Result indicates that the microbial agents upgrade considerably soilproperty of alkaline soil.3.15indexes and Principal Component Analyses were used to evaluate soilfertility quality of alkaline soil, PC1represents alkaline phosphates activity andsolubility Ca2+; PC2represents organic matter; PC3represents fungi; PC4representsexchangeable Na+. It shows that four PCA reflect soil microorganism, enzymeactivities, fertility and ion concentration of alkaline soil, and are able to explain therelationship between the factors and soil fertility quality.4. The soil fertility quality evaluates result show that there is an improvement onsoil fertility quality by applying different phosphate-solubilizing microbial agents onalkaline soil. The integrate evaluation of the alkaline soil to soil fertility qualityindicates that the soil fertility quality was as follow: I-B-14> O-B-10> I-A-5> O-A-16> I-B-13> I-A-12> O-A-14> O-B-20> CK. The results indicate thatphosphate-solubilizing microbial agents can improve fertility quality of alkaline soil,and the highest affection on fertility quality of alkaline soil was displayed in I-B-14.5. The soil fertility quality evaluate and Cluster Analysis result show that there is difference on soil quality by applying different phosphate-solubilizing microbialagents on alkaline soil, and soil quality distinction of organic phosphate-solubilizingmicrobial agents are larger compared with inorganic, this may be associated withmetabolic ways and products by different phosphate-solubilizing microorganism. Theresult show that the soil fertility quality evaluate and Cluster Analysis could reflectsoil change by applying different phosphate-solubilizing microorganism, besides,could provide scientific evidence for soil fertility quality assessment of differentmicroorganism type.