A Preliminary Study On The Quality Of Facility Soil In Shaanxi Province

In recent years,with facility agriculture rapidly developing in Shaanxi province,the problems of soil nutrient status are more and more obvious.By a long period of planting,but some researches were carried out and some results were obtained.However,the results were limited to a certain area and only represented a smaller geographical area without systematically the biochemical properties of soil.Therefore,this study selected soil samples from 9 counties(districts)of 7 cities in Shaanxi province,in which the main planting areas of vegetables reached 2.85 million acres.These soil samples were roundly determined and analyzed about salinity,pH,nutrients and enzyme activities.Correlation analysis and principal component analysis(IFI)of these indexes were used got comprehensive score and comprehensive index evaluating soil fertility.Calculating the total enzyme activity of TEI and exploring the characteristics of soil biochemical activities that reveal the relationship between soil nutrients and soil enzyme activities and primary structure biological indexes of facility soil fertility in Shaanxi.All in all,it provided theoretical basis for the sustainable development of facilities vegetable industry in Shaanxi and reducing the use of chemical fertilizers.The study has the following conclusions:1.There are more differences in facility culturing soil nutrient status of Shaanxi province,especially trace elements,and nutrient changes are irregular.The soil fertility level of Shaanx i province is divided into 3 grades including higher,secondary and Low through clustering an alysis,which founded that the proportions of sampling sites in Northern Shaanxi were 2.90%,13.04%,and 84.06%,respectively,the proportions of sampling sites in Guanzhong were 6.65%,36.06%,and 57.38%,respectively,and the proportions of sampling sites in Southern Shaanxi were 4.00%,36.00% and 60.00%.Analysis of variance and multiple comparisons indicated that conductivity and the content of available Cu were the main factors limiting the soil fertility in Northern Shaanxi,the indexes of pH,organic matter,available phosphorus,available potassium and available manganese were the important factors restricting the fertility of facility soil in Guanzhong area,nitrate nitrogen is the main factor limiting the soil fertility in Southern Shaanxi.2.Soil enzyme activities differ from different areas,so it can be used as a sensitive indicator of soil fertility.In addition to converting enzyme,soil enzymes and the most of soil chemical properties were significantly correlated indicating that soil enzyme activities may reflect fertility level of facility soil;analyzing all indexes determined by Principal component analysis that got the soil fertility information system,which can well reflect the variation of soil fertility.The comprehensive score and TEI are significantly related to physical and chemical properties of soil,and comprehensive score and TEI also showed a significant positive correlation.It shows that the soil enzymes can reflect the fertility level of facility soil,especially the indicator of TEI.3.The distribution of soil nutrients were unbalance and organic fertilizer and trace element fertilizer were insufficient.Phosphatase kinetic parameters are closely related to the chemical properties of the soil.Through the principal component analysis,the soil fertility information system constructed by the dynamic parameters of alkaline phosphatase can evaluate the level of soil fertility in the facility,and the alkaline phosphatase Vmax,Km,Vmax/Km can be used as important indicators of soil fertility.Soil fertility is divided into three grades according to cluster analysis founding that high fertility soil accounted for only 4.44% in Shaanxi,the results of single factor variance analysis and multiple comparison show that the contents of available manganese and copper are the main limiting factors in facility soil fertility,followed by pH,zinc,iron,the other is not the limiting factor.In summary,the present study shows that the soil fertility of major facilities soil varies greatly in Shaanxi Province,and the soil biochemical activity needs to be coordinated and controlled.The comprehensive scores,TEI,and comprehensive index values obtained can be used as monitoring indicators of the soil quality of facilities,and it is recommended to adopt reasonable Fertilization programs for fertilizing the soil,etc.,ultimately provide an important basis for the rational reduction of facilities and fertilizers.