土壤氮磷钾对五倍子单宁含量的研究分析

为了研究土壤氮磷钾对盐肤木上五倍子单宁含量的影响，提高五倍子单宁含量，指导五倍子产区倍农的实际生产。采用分光光度法，测定了张家界五倍子主产区盐肤木上不同生长期五倍子、树枝干、树叶的单宁含量和五倍子各物理特征以及其生长土壤中的氮磷钾含量的相关数据。应用相关分析、逐步回归分析等统计方法，探讨了不同生长期的五倍子单宁含量与它们之间的关系。结果表明：盐肤木上处于生长期的五倍子，它的单宁含量与五倍子干重呈显著正相关(P=0.000＜0.01)；而处于成熟期的五倍子，它的单宁含量不仅与五倍子干重有相关性，还与五倍子内含物表现出显著正相关，其显著性均为P=0.000＜0.01。同时，土壤养分对不同生长时期五倍子单宁含量的积累也存在明显差异。在生长期，土壤氮、磷养分与五倍子单宁含量的相关系数分别为0.628和0.646；而在成熟期，它们的相关系数分别为-0.473和0.420。因此认为，土壤养分因子是影响不同时期盐肤木上五倍子单宁含量积累的重要生态因子之一。

Effect Analysis of Soil Nitrogen, Phosphorus, Potassium on Tannin Content of Gallnuts

The study aims to ascertain the effect of soil Nitrogen (N), phosphorus (P) and potassium (K) on tannin content of gallnuts in different growth periods. Research on gallnuts could not only improve the tannin content, but also guide farmer’ s production practice. Spectrophotometric method was adopted to measure tannin content of gallnut, branches, leaves and the gallnut physical characteristics, soil available nutrient factor in different growth periods on Rhus chinensis Mill in Zhangjiajie main gallnut producing areas. With the application of statistical methods such as correlation analysis and stepwise regression analysis, the author explored the relationship between tannin content of gallnut in different growth periods and the above indexes. Results showed that, for gallnut in the growing period on Rhus chinensis Mill, tannin content and its dry weight were positively correlated (P=0.000＜0.01); for gallnut in the mature stage, the tannin content was correlated with dry weight, and had a significantly positive correlation with gallnut inclusions, its significance was P= 0.000＜0.01. At the same time, in different growth periods, there were significant differences between soil nutrients and tannin content accumulation in gallnut. In the growth stage, the soil nutrient nitrogen and phosphorus and the tannin content had the correlation coefficients of 0.628 and 0.646, respectively; but in mature stage, their correlation coefficients were - 0.473 and 0.420. So, the soil nutrient factor was one of the important ecological factors that affecting the tannin content accumulation of gallnuts on Rhus chinensis Mill.