Studies on Nutrient Yield of Green Cut Jerusalem Artichoke : (Part 8) Relations between nitrogen quantities supplyed and nutrient yield

[摘要] (1) In sand cultures, relations between the concentration of nitrogen supply and the nutrient yield were examined. The absorption coefficient and the distribution of N in the plant were also studied. (2) Regarding the height of plant and the dry matter yield, the largest figures were observed in the N-100-mg plot. With N-contents in the plant below 1 % (by the N-20-mg plant), no lateral shoots developed. (3) In regard to the leaf-stem-ratio, the smallest figure was registered in the N-50-mg plot. This ratio was found to rise as the concentration of nitrogen increased. (4) Both in the leaf and in the stem, the protein content increased as the N-concentration was raised. The rate of increase and drop of T.P./C.P. value were observed more remarkably in the leaf than in the stem. (5) In the stem, the carbohydrate showed a trend inverse to that of the protein content. In the leaf, however, the carbohydrate content was small in the N-lacking plot. In the N-50-mg plot, it recorded the largest figure, but decreased as N became surplus. Saccharide showed the same inclination as that of the dry matter yield. (6) Both in the leaf and the stem, crude fiber became more as the N-concentration increased but the crude ash content decreased to the contrary. (7) The protein yield showed a remarkable increase in the N-200-mg plot. However, the increase became small after N-concentration increased more. Regarding the carbohydrate yield, the highest figure was observed in the N-100-mg plot. (8) The largest rate of distribution of N absorbed was found in the leaf, the root followed it and then the stem. However, under the N-lacking condition the rate of distribution was large in the root, but small in the stem. As N-concentration became larger, the rate in root decreased, but maintained the level of about 24 %. The rate in the stem decreased gradually. (9) As N-concentration became higher, the rate of N-absorption decreased. The efficiency of protein production and the index of dry matter produdtion likewise decreased. (10) From the foregoing, it is deduced that the rate of proper amount of dry matter production in the Jerusalem artichoke plant is N : P2O5 : K2O=1 : 0.5 : 1, and that of the nutrient production is 2 : 0.5 : 1.

[学科分类] 农业科学（综合）