Abstract: This paper summarized results of experiments with potassium and magnesium fertilization on different tea types, carried out in various tea growing areas of China. Analysis of typical soil samples from various tea growing regions indicated that the supplying capacities of K and Mg in more than half samples were classified as deficient and did not meet the demands of tea plant under present production levels. Fertilization with K and Mg greatly increased yields of the major tea types, e.g. green tea, black tea, and Oolong tea. In addition to improved productivity, it is shown that quality, e.g. free amino acids, polyphenols, caffeine as well as theaflavin and thearubigin contents of black tea were largely increased. Resistances to drought and diseases were also improved by K application. Field experiments showed that potassium chloride had similar effect as potassium sulphate. The overall results confirmed that balanced nutrition including the nutrients K and Mg is an important measure to improve productivity of tea. A preliminary recommendation of K and Mg fertilization rates based on soil K and Mg status was proposed.

Key words: Tea, Potassium, Magnesium, Balanced nutrition, Quality, Yield, Tea soil