Soil Fertility of Paulownia Plantations in Southern Hilly Mountain Areas
This study focuses on Paulownia plantations in the southern hilly mountainous areas,evaluating the overall soil nutri-ent status according to the grading standards of the National Second Soil Survey and employing principal component analysis for a comprehensive assessment of soil fertility.The results showed that the average mass fractions of total nitrogen and al-kali-hydrolyzed nitrogen in the soil of Paulownia plantations are 1.21 g·kg-1 and 113.66 mg·kg-1,respectively,placing them in the upper-middle grade level.The average mass fractions of total potassium,available potassium,and organic mat-ter are 13.07 g·kg-1,68.17 mg·kg-1,and 18.50 g·kg-1,respectively,which fall into the lower-middle grade level.The average mass fraction of total phosphorus is 0.35 g·kg-1,indicating a low grade level overall.The average mass frac-tion of available phosphorus is 2.68 mg·kg-1,classifying it in a very low grade level.Principal component analysis shows that the comprehensive soil fertility score for Paulownia plantations ranges from-1.97 to 2.59.Using cluster analysis,the 115 sampling sites can be categorized into four levels of soil fertility:extremely high,high,medium,and low,with the percentages of sites in each category being 6.09％,31.30％,43.48％,and 19.13％,respectively,indicating that the pre-dominant level of comprehensive soil fertility is moderate.There is considerable variation in soil fertility among different planting areas,with the highest overall levels found in the Paulownia plantations of Jingshan City,Jingmen City,Zhongx-iang City and Xianning City in Hubei Province,while the lowest overall soil fertility is observed in Chongyang County,Hu-bei Province.
万方数据
维普
