Soil Distribution Based Data Investigation And Evaluation For The Establishment Of The Minimum Data Set

As the most important part of land,soil is the fundamental guarantee for mankind's survival.However,unreasonable utilization of mankind and natural factors lead to the degradation of soil resources.In order to solve the contradiction between the reduction of soil area and the increasingly prominent human development,the project team made use of waste materials from production and living such as sludge and biogas residue for soil compost.This study is a database for the establishment of quality evaluation index for the compound soil,and uses the method of mathematical statistics to establish the minimum data set of the composite soil quality evaluation index.Artificial soil compounding technology is the use of land improvement,surface soil replacement,soil remediation(high temperature treatment,replacement of soil)after the improvement of mine rehabilitation,land reclamation improvement,heavy metal plant restoration,bio-energy closed planting.After the study decided to select the representative of the quality of natural soil as the target soil,the final selection of the following eight soil samples: Liaoning,Jilin,Hebei,Tianjin,Henan,Jiangsu,Sichuan,Xinjiang.The purpose of this study is how to evaluate compound soil.Soil quality evaluation index screening is a very important and difficult basic work.Due to the compounding of the soil,the raw materials are ground to a certain particle size for recombination.Therefore,the present study focuses on physical indexes such as the selection of particle size composit ion and stability of aggregates,and adds a biological index,microbial biomass,The following indicators were identified and suggested: soil mechanical composition,large water-stable aggregates,hydraulic conductivity(permeability coefficient),capillar y porosity,water retention,maximum moisture content,organic matter,PH,conductivity,Effective P,available K,cation exchange capacity(CEC),microbial biomass carbon.In this study,the reference range of each quality index was determined.The reference range of each index was as follows: the reference range of sand content in soil mechanical composition was 40-70%;the reference range of powder content was 25-50%.The reference range of clay content is only 5.95% because of the high degree of dispersion of the measured data.The reference range of 5-2mm content in water-stable macro-aggregates is 6-10% Of the content range of 5-8%;1 ~ 0.5mm content of the reference range of 8 ~ 12;0.5 ~ 0.25 mm content of the reference range of 8.5 ~ 16.5%.The capillary porosity reference range is 40 to 52%.The reference range of organic matter is 0.5 ~ 2.1%.Hydrolysis of nitrogen reference range of 95 ~ 220mg/kg.Available phosphorus reference range of 20~75mg/kg.Available potassium reference range of 92 ~ 205mg/kg.Microbial biomass carbon reference range of 0.2 ~ 0.4mg/g.In this study,we used correlation analysis,principal component analysis and Norm calculation to quantitatively determine the minimum data set(MDS)of compound soil quality evaluation.The minimum data set can provide targeted and quantitative evaluation indicators for soil compaction in the future.The final data set includes 8 indicators of the content of silt,sand content,capillary porosity,average mass particle size(MWD),water retention,organic matter,available phosphorus and microbial biomass carbon.