Soil Nutrients Distribution And Assessment In Xinjiashan Of Qinling Mountains

In this study,the spatial distribution of soil nutrients such as soil pH,SOM,TN,AN,TP,and AK was first studied by combination methods of classical statistical and GIS techniques in the Qingling Xinjiashan forest area.Then,the main component analysis method was used to comprehensively evaluate the soil nutrient status in the study area.And finally,based on the soil nutrient status in the Xinjiashan forest area,the soil nutrient grading standard for the forest soil was attempted.The results are as follows:1.The average contents of SOM,TN and AN in the forest area of Xinjiashan were 36.93g/kg,1.79g/kg,and 181.65mg/kg,respectively.The average content of TP was 0.39 g/kg,showing a lack of level;the content of AK was high,with an average content of 236.143mg/kg.The variability of soil nutrients in forest areas was as follows: AK> TP> SOM> TN >AN.2.The soil in the study area is mainly weakly acidic,and the spatial distribution shows that the acidity in the north is stronger than that in the southern area.This is mainly related to the trend that the elevation of the study area is gradually increasing from south to north.Within a certain range of elevation,As elevations increase,rainfall increases,and leaching increases,resulting in a decrease in soil pH.The spatial distribution of soil organic matter,total nitrogen,and alkali-hydrolyzed nitrogen also appears to be lower in the northwest and higher in the southeast,within a certain elevation range.As the altitude rises,the temperature gradually decreases and the microbial activity weakens,causing the organic matter to decompose slowly,causing massive accumulation of organic matter.The total phosphorus content in the soil is lower than the middle level,and the overall pattern is that the eastern part is high in the northwest,and the lower part is in the middle and the south.3.Through the analysis and analysis of the soil nutrient status in the whole forest area,using the principal component analysis method for comprehensive evaluation,the score of the soil nutrient comprehensive score in the study area was distributed in the range of 17.13–157.07,with an average of 66.13,and the soil nutrient was under the middle deviation.The level is generally decreasing from northwest to southeast.4.Based on the analysis of 0-20 cm soil nutrient in the forest area,and referring to the nutrient status of forest soil in many regions of China,the grading standard for the nutrient grade of forest soil was initially proposed to provide scientific basis for the management of forest soil nutrients in China.