Studies on Nitrate Nitrogen Contents in Forage Crops. : 2. Effect of four levels of light intensity and two levels of nitrogen on yields and nitrate natrogen contents of Bahiagrass (Paspalum notatum FLUGGE) and Bermudagrass (Cynodon dactylon PERS.)

[摘要] Experiments were carried out to determine the effect of light intensity and nitrogen fertilizer supply on the yields and nitrate nitrogen contents in bahiagrass and bermudagrass. Four levels of light intensity were 100, 75, 50, and 25 per cent of incident light, and two levels of nitrogen fertilizer were 4g (high-N level) and 1g (low-N level) per pot (1/5, 000 a) respectively. A reduction in light intensity was associated with a decrease in yield, and the an increase in nitrate contents in both grasses. The yields in both grasses tended to be higher in high-N level than in low-N level under the conditions of sufficient light intensity (100 and 75 per cent of incident light), but under insufficient light intensity (50 and 25 per cent of incident light) this tendencies were reversed. From this experiment, accumulation of nitrate nitrogen in plants indicated that the rate of assimilation could not keep pace with the rate of uptake. Protein contents in both grasses tended to be higher in high-N level plots than in low-N level plots under all experimental conditions.

[学科分类] 农业科学（综合）