化成肥料が砂丘地のブドウ樹に及ぼす肥効について

In this paper the effects of synthetic fertilizer and mixed fertilizer on the growth, yield and fruit quality of Delaware grapes (9-year-old ) and DK-151 grapes (5-year-old ) and the issue of N, P and K in both fertilizers by rainfall were observed.
(1)On the length growth, the thickness on basal part and the fullness of the current shoot, synthetic fertilizer was more excellent than mixed fertilizer. Besides, N and starch contents in vines and fibrous roots grown with synthetic fertilizer were much more than those with mixed fertilizer.
(2)The yield, the weight and length of bunch, the weight and number of berries grown with synthetic fertilizer were superior to those of mixed fertilizer, but the former gave no good effect on both soluble solid and acid contents.
(3)The contents of N and K in leaves in synthetic fertilizer plot were higher than those in mixed fertilizer plot and little difference of P contents was found between each plot. The amounts of N and K issued from the soil in mixed fertilizer plot were a little higher than those of synthetic fertilizer, but the relation was reciprocal in the case of P. It seems that one of the causes of the poor growth of the grape vines in mixed fertilizer plot is due to the much quantity of the early issue of N and K.