低山丘陵区不同坡位茶园土壤肥力特征研究

南方低山丘陵区是我国茶园的集中分布区域, 研究其土壤肥力状况是改善茶园土壤养分状况、实现茶叶安全高效生产和可持续发展的基础.选择川西茶区典型低山丘陵茶园, 通过野外调查与样带采样研究土壤养分性质, 利用主成分分析等多元统计方法定量化比较了不同坡位及对照间土壤肥力质量.结果表明: (1)茶园土壤中砂粒含量最高, 平均占总量的39.13%, 其次是黏粒, 粉粒含量居第3位;土壤pH低于4.5, 有机质和全氮含量较低, 速效氮含量较高, 速效磷缺乏, 速效钾变化不显著.与林地、撂荒地相比, 茶园土壤各粒级含量变化规律不明显.有机质和全氮除在下坡位略高于撂荒地外, 其他坡位均小于撂荒地和林地;速效养分变化规律不显著.(2)茶园土壤肥力沿坡面变化明显, 以上坡位为基准, 土壤肥力指数PI值为零, 中坡位PI值(-13.64%)低于上坡位PI值(0)和下坡位PI值(14.39%).(3)与撂荒地、林地相比, 茶园的土壤肥力综合指数QI值最低.茶园、撂荒地、林地的QI值分别为0.56、1.11和2.73.

Soil fertility in tea plantations in different slope positions and elevation regions

The southern low mountain and hilly areas are the largest tea plantation regions in China. Soil fertility studies are therefore fundamental for improving soil nutrient status; implementation of safe, high and effective production; and sustainability of tea plantations. Hence soil fertility study on a representative tea plantation in western Sichuan was conducted through field investigation, transect sampling and experimental analysis. The principal component analysis (PCA) and multivariate statistical analysis were used to compare soil quality under different land-use types (QI, fertility index based on land-use type) and slope positions(PI, fertility index based on slope position). The study shows that in tea plantation soil, grit accounts for 39.13%, followed by clay and then silt. Average soil pH is lower than 4.5, which is the standard for soils in high quality tea plantations. The soils are rich in available N, but low in soil organic matter, total N and available P. There is insignificant change in available K. Soil particle content and available nutrient have no consistent changing pattern compared with those in waste lands and forestlands. Organic matter and total N in soils under tea plantations are lower than those under waste land and forestland, except for waste lands on low slopes. The quality of soil fertility in tea plantations changes drastically with slope position. PI is -13.64% for middle slope position, 0 for upper slope positions and 14.39% for lower slope positions (taking the zenith as datum).QI in tea plantations is lowest compared with waste lands and forestlands. For tea plantations, waste lands and forestlands QI is 0.56, 1.11 and 2.73 respectively.