Study On The Relationship Between Soil Environmental Geochemical Conditions And The Yield/Quality Of Soybean

Soil is not only the material basis for human survival,but also the most basic component of the ecosystem.Soil,as a repository of elements,has a direct impact on the yield and quality of agricultural products.In recent years,with the development of the population and economy,the rapid development of the industry and some improper human activities,the land exploitation level is increasing,the land degradation and the soil environment pollution are becoming increasingly serious and the gricultural soil environmental quality is declining,affect the growth of crops,but also endanger human health.The survival and reproduction of human beings are closely related to the survival of agriculture,and the basic resource of agricultural survival is the soil.Therefore,the quality of soil environment is widely regarded by the society and is an important research content of environmental science.Northeast is the best ecological region of soybean and the largest soybean producing area in China,the sown area and production accounted for half of the country.Jilin has a long history of soybean cultivation and is known as "the hometown of soybeans".A total of 2667 surface soil samples and 659 deep soil samples were collected in this study;The study area of soybean main producing area is located in Nong’an county,No.8 town and Xiangyang town of Yushu City.A total of 90 surface soil samples were collected,23 soil elements,3 soil physicochemical indexes,and 13 efficient status of elements in the soil were analyzed.a total of 14 soybean seeds samples were collected,17 element contents of soybean seeds,23 nutritional ingredients were analyzed;field work and indoor analysis data were basically satisfied with the statistical analysis requirements.A number of important field data and indoor analysis data were obtained,which laid the foundation for the analysis of geochemical characteristics and correlation analysis of soybean ecological environment.In this study,land black soybean planting area of Yushu city as the key research area,and choose the different ecological environment of soybean planting area in Nong’an County as the reference area,studying the composition and distribution of harmful and beneficial nutrient elements in soil and soybean seeds,and identifying the nutrient availability.Through studying the effective content characteristics of nutrient elements,the geochemical characteristics of soybean quality formation and the related factors affecting the quality of soybean were identified.Combined with agro-ecology environmental factors such as environment,climate and soil elements,the comprehensive assessment of soil environmental quality and soil fertility was performed;finally,the quantitative structure-activity relationship model for soil element and soil physical and chemical properties and yield/quality of soybean was established by partial least squares(PLS),and the interval two-stage and chance random constraint method was used to establish optimal model of soybean yield to provide the basis for the development of high yield and high protein soybean area.The main conclusions of this study are as follows:It is found that in the aspect of the geochemical distribution characteristics of soil elements,the major elements and trace elements of the soil required are sufficient and soil beneficial elements and health elements are close to the soil environmental background values as well as soil harmful elements content do not reach the pollution value;In the aspect of soil element correlation,the contents of Mo and Hg in the soil of the study area are significantly correlated with the total element content of soil at the level of 0.01 and there are three elements such as P and Al that are significantly related to the total element content of soil at 0.05 level.There are significant positive correlations between available Fe,available Mn,available Zn and Mg-exc and the total element content of soil in the study area at 0.01 level while there are significant negative correlations between the available B and Ca-exc and the soil total element content at the 0.01 level,moreover,N03-N and available K have a significant correlation with the soil total element content at the level of 0.05.There are significant correlations between Ca-exc,available Fe,available B and soil physical and chemical indexes at 0.01 level and Nitrate nitrogen,available Zn are significantly correlated with soil CEC and pH at 0.01 level,in addition,there is a significant correlation between available K and organic matter as well as CEC at 0.01 level and available P,Mg-exc and organic matter was significantly correlated at 0.05 level.In the study area,the mean element content of soybean seeds was as follows:K>P>Mg>Ca>Fe>Zn>Mn>Cu>Ni>Mo>F>Cr>Cd>Se>Pb>As>Hg.The difference between the elements is obvious because the highest value of K element content of 17705.02mg/kg,while the lowest value of Hg element content is only 0.0008mg/kg.The regional differences in nutrient total content of soybean seeds in the study area is shown that Nong’an Qiangang Nutrition Total<Yushu Xiangyang Nutrition Total<Yushu No.8 Nutrition Total.The soil environmental quality of the study area as a whole is in accordance with the secondary standard of Soil Environmental Quality Standard(GB15618-1995)and it is suitable for planting soybean,but the content of Cd in the partial area of Nong’an Qiangang is over standard.In the study area,the most abundant of soil fertility is in the town of Yushu No.8,followed by the Yushu Xiangyang Town and Qiangang Nong’an County,which are suitable for planting soybean,but the pH condition needs to be improved.The quantitative structure-activity relationship between soybean yield/quality and soil quality(soil element,soil pH,organic matter content and cation exchange capacity)was constructed by the method of partial least square(PLS)in the SPSS software,and the known 24/11 groups of soybean yield/quality data in the soybean main production area were placed in the training set and the 6/3 groups of data were placed in the test set,respectively.The simulation results for models show that the model correlation coefficient R was 0.909,0.912,0.900 and 0.899,R2 was 0.826,0.832,0.810 and 0.808,R2adj was 0.802,0.821,0.804 and 0.801,and all regression coefficients were tested by statistics(P<0.05);In addition,the correlation coefficient between the experimental data and the predicted data R2pred is 0.961,0.935,0.923 and 0.956,respectively,indicating the model has good prediction ability.Moreover,soil element B,Mo,Se,K,N,P,Zn,As,soil pH and cation exchange capacity has a positive effect on soybean yield,while element B,Mo,Se,K,N has a positive effect on soybean quality.This study provides theoretical support for improving the soil to improve the yield and quality of soybean in the future.This study is aimed at the social and economic development of soybean in Jilin Province,the development of soybean and the existing problems of soybean development,combined with the requirements of the sustainable use of regional land resources,the land resources and socio-economic conditions of soybean producing areas.The yield and quality model(for example(?)of the corresponding soybean were obtained by using the two-stage and randomized stochastic constraints.In view of the status of soybean cultivation in the region,the corresponding improvement measures were put forward from the beneficial soil elements,harmful elements,organic matter and other physical and chemical properties.