Effect of only organic fertilizer application to use much during winter and spring on yield and quality of green tea

Abstract

As an attempt to support organic tea cultivation, we examined the effects of the application of only organic fertilizer on green tea. Our findings are described below. We compared the routine method wherein a combination of chemical and organic fertilizers is applied with a method wherein only an organic fertilizer is applied; this method involves a liberal use of the organic fertilizer from winter to spring, and the fertilizer was applied at an annual amount of 50 kgN/10a. The organic fertilizer method had almost no influence on yield, but the quality of the 1st, 2nd, and 3rd crops of green tea deteriorated during the 1st and 2nd years. However, in the 3rd and 4th years, the crop yield and quality was the same as that with the combined fertilizer method. On the basis of this primary result, it was thought that an increase in the protein-like organic nitrogen (neutral phosphate buffer-extractable organic nitrogen, PEON) concentration in the soil leads to an increase in nitrogen absorption by the tea plants. Moreover, the use of the organic fer tilizer method also led to an increase in the