关键词: 湄潭茶园, 土壤养分, 土壤肥力质量, 土壤肥力综合指标值, 主成分分析

Abstract: This research investigated the soil nutrient status and balance in Meitan tea plantations. Six indicators were selected (pH, organic matter, total nitrogen, alkaline nitrogen, available phosphorus and available potassium) and data on these collected for six categories of tea plantation. The data were evaluated by principal component analysis. It was found that: 1) The soil pH of Meitan tea plantations ranged from 3.73 to 7.26, with an average value of 5.01. In 61.11% of the surveyed tea plantations, the soil tests satisfied the standard set for high quality tea plantations. Hence, the soil pH of Meitan tea plantations was generally suitable, although soil in 16.67% of the tea plantations had an acidification trend. 2) The contents of organic matter, total nitrogen, alkaline nitrogen, available phosphorus and available potassium in Meitan tea plantations were in most cases rich, with average values of 22.84 g·kg^-1, 1.43 g·kg^-1, 124.50 mg·kg^-1, 44.16 mg·kg^-1 and 135.61 mg·kg^-1, respectively. For the same list of tests, soil in 61.11%, 70.37%, 61.11%, 55.56% and 59.26%, respectively, of the tea plantations met the standard for high quality tea plantations, but the status for individual nutrients differed between plantations. 3) The integrated fertility index (IFI) range for the surveyed Meitan tea plantations was 0.179-0.989, with an average value of 0.683. In 51.85% of the tea plantations soil was at level Ⅰ status, and in 31.48%, it was at level Ⅱ. Hence, the soil nutrient status is generally good. There were obvious differences in IFI between the different categories of tea plantations, with the ranking being: medium mountain yellow soil>hilly yellow soil>hilly calcareous soil>low mountain yellow soil>medium mountain calcareous soil>low mountain calcareous soil. 4) There was a very significant negative correlation between pH and organic matter, total nitrogen, and available phosphorus, and a significant negative correlation of pH with alkaline nitrogen. There was a significant (P<0.05) and a very significant (P<0.01) positive correlation between the nutrient indexes; i.e. the values for the various nutrients at any one test site were relatively close and homologous. Tea plantation values for soil pH were negatively correlated with IFI (P<0.01), and test values for other nutrients were positively correlated with IFI (P<0.01).

Key words: Meitan tea plantations, soil nutrient, soil fertility quality, integrated fertility index (IFI), principal component analysis