钾和镁对乌龙茶产量和品质的影响

田间试验结果表明，施用钾、镁肥可使乌龙茶的产量提高９％—３８％；茶叶中的游离氨基酸和咖啡碱的含量也有所提高；茶多酚含量因施钾而增加因施镁而减少，但酚／氨比均趋于合理，提高了乌龙茶的适制性。施钾、镁肥还改善了乌龙茶的香气组成，使橙花叔醇等香气成分的含量明显升高。乌龙茶的等级与其含镁量呈显著正相关，即品质好者其含镁量也高。文中还对钾、镁对乌龙茶生化品质的影响和在乌龙茶产区施用钾镁肥的重要性进行了讨论

Effects of Potassium and Magnesium on the Yield and Quality of Oolong Tea

A field experiment including five treatments of CK,K 1,K 2,K 1+Mg and K 2+Mg was conducted to investigate the effects of potassium and magnesium on the yield,the chemical components and the aromatic compounds of oolong tea.Samples of various grade oolong tea were also collected from market and Mg contents in the teas were determined to evaluate the relationship between Mg content and tea grade.Results showed that the yield of fresh leaves increased considerably following K and Mg fertilizer applications.The increasing rates were between 9%-38% during the two years' study.The contents of free amino acids and caffeine in tea leaves also increased with K and Mg applications.The polyphenols increased in the K treated tea leaves but reduced markedly in the Mg treated leaves while the ratio of polyphenols to free amino acids decreased in all treatments with K and Mg which is thought beneficial to oolong tea quality.Some important aromatic compounds such as nerolidol were increased,suggesting the improvement of aromatic property,by K and Mg applications.The quality of marketed oolong tea was closely correlated with the Mg content in tea.It could be concluded from the above results that applying K and Mg will be an effective agronomic measure to promote the productivity of oolong tea grown on the soils deficient in available K and Mg.