Growth and nutrient absorption characteristics of three commercial cabbage cultivars under varying nitrogen levels.

摘要

The growth and nutrient absorption of 3 cabbage cultivars, Kogetsu, Syunrai 500 and YR Ryokuhou, were studied under varying rates of nitrogen application (100, 150, 200, 250 and 300 kg N/ha). In all cultivars, growth and N concentration varied according to N application rate. Nitrogen absorption patterns were similar during the first growth stage in all cultivars. However, applied N efficiency (fresh weight of cabbage head/kg N applied) was highest at 100 kg/ha in Kogetsu, 150 kg/ha in Syunrai, and500 and 200 kg/ha in YR Ryokuhou. In Kogetsu, N absorbed during the outer leaf development phase contributed to growth, while N absorbed during the head development phase contributed in Syunrai 500. The concentrations of P, K, Ca and Mg in the plants varied with the N rate. Moreover, the K content varied in all cultivars during the head development phase and at low N rates. The Ca concentration in the outer leaves of Kogetsu was higher than in the other cultivars.