Effect of low application of nitrogen fertilizer on yield and ingredients of crude tea [Camellia sinensis] leaf

The content of total nitrogen in the new shoot increases when a lot of fertilizer of nitrogen are manures, high-quality green tea is produced, and it has had dealings over tea by high price. The multi fertilizer cultivation has been done by centering on the fertilizer of nitrogen for years. The load to the environment with multi fertilizer becomes a problem in agriculture. 'Yabukita' is grown by about 80 percent of the cultivation area as for tea in Japan. But the tea plant that passes 25 years called an economic age of a tree has increased. It plants from 'Yabukita' to other cultivar little by little to expand plucking date or make green tea with the feature. The crude tea quality is worry in the reduction of the amount of fertilizer from circulation and the production side by centering on 'Yabukita'. Most is researched by 'Yabukita' in the soil fertilizer field of tea, the examination by each cultivars a pressing need. In this research, the tendency to the nitrogen fertilizer amount reduction in the tea cultivar is clarified. Effect of reduction of the amount of applied nutrient by using a general organic compound fertilizer from tea planted time in 20 cultivar and line, the amount of fertilizer, and the annual was done in the minute grain brown forest soil. Reduced amount of the nitrogen fertilizer, the first crop of green tea, but it decreases the second crop of green tea was decrease when reduced quantity of nitrogen fertilizer applicated to 30kg/10a in a year. The crude tea ingredient of the green tea, a tendency to decrease in total nitrogen, free amino acid, theanine content about tannin content is tendency to increase by reducing quantity of nitrogen fertilizer application. The difference of neutral detergent fiber was not seen between quantity of fertilizer application in optimum plucking time. Because the total nitrogen, free amino acid, and theanine content of the early cultivar are overall high, and amount is high in the late cultivar, it is necessary to examine the cultivation management according to each cultivar for the manure amount reduction.