The Korean Journal of Crop Science ISSN:0252-9777(Print) 2287-8432(Online) 한국작물학회지

This study was carried out to investigate the optimal nitrogen concentration level suitable for forage rice growth by hydroponic cultivation in the salinity concentration of 0.1~0.3% which is similar to that of Muan reclaimed paddy field, and based on this results, to estimate optimal nitrogen fertilization level by field experiment in Muan reclaimed paddy for maximum forage production by cultivation of Yeongwoo rice. As a result of the growth response to the salt and nitrogen concentrations in the hydroponic cultivation experiment, the growth amount increased as the nitrogen concentration increased in the range of 0~24 me/L in the absence of salt stress. However, at a salt concentration of 0.1~0.3%, the growth amount was the highest at a nitrogen concentration of 12 me/L, and at higher nitrogen concentrations of that, the rice growth decreased as the nitrogen concentration increased. Therefore, nitrogen concentration of 12 me/L was judged to be an appropriate concentration for forage rice growth at salt concentration of 0.1~0.3%, and a nitrogen fertilization amount level corresponding to a nitrogen concentration of 12 me/L was actually applied to the Muan reclaimed paddy field for forage rice cultivation during two years. The amount of nitrogen fertilizer was tested with three treatments, which are 18 kg/10a considered appropriate, and 1.5 times and 2 times of the appropriate amount, and the planting density was tested with 2 treatments of 15 hills/m² and 26 hills/m². As a result of the reclaimed paddy field experiment, the yield was the highest when nitrogen fertilizer was applied at 18 kg/10a in the planting density of both treatments. Looking at the yield according to planting density, the high planting density plot yielded higher than the low planting density plot. In other words, when the planting density was 26 hills/m² and the nitrogen fertilization amount was 18 kg/10, the highest dry matter yield of 1,763 kg/10a was obtained. From the results of hydroponics and reclaimed field experiments, we could conclude that the productivity of forage rice decreased more as the nitrogen concentration increased when the nitrogen concentration was higher than the optimal level under salt stress.