2001년 국립식량과학원 인공기상실에서 수경재배로 규산의 시용 여부가 영양생장기 벼의 수분과 질소흡수량에 미치는 효과를 조사하여 규산시용 여부 및 공급된 질소의 형태별 처리에 의한 시험품종들의 수분과 질소이용효율을 산출한 결과는 다음과 같다.1. 처리 67일 후의 벼 건물중은 규산처리 시험구 및NH4+NO3 혼합시용 처리구가 규산을 처리하지 않은시험구 및 NH4 단독시용 처리구보다 유의하게 증가하였음.2. 이앙 후 67일간 조사된 벼의 수분흡수량은 규산처리와 규산 무처리 간의 차이가 없었으나 질소흡수량은규산 무처리에 비해 규산처리구에서 유의하게 증가하였음.3. 질소형태별로는 NH4 단독 시용보다 NH4+NO3 혼합시용에서 규산처리 여부와 관계없이 수분과 질소흡수량이 월등히 많았음.4. 수분이용효율은 규산처리 시험구가 규산을 처리하지않은 시험구에 비해 유의하게 증가하였으나 질소형태별 처리에서는 차이가 없었음.5. 질소형태의 혼합처리가 암모늄태 단독처리보다 질소흡수량은 유의하게 많았으나 질소이용효율은 감소하였음.

This experiment was conducted to investigate the variation of nitrogen use efficiency, nitrogen uptake efficiency, physiological utilization efficiency and their relationships with growth characteristics in the 28 Korean rice cultivars. Nitrogen use efficiency of 28 rice cultivars was 47.74, nitrogen uptake efficiency was 0.71, and physiological utilization efficiency was 68.76 in average. Nitrogen use efficiency of rice cultivars had low variation ranged from 44.09 to 51.91, but nitrogen uptake efficiency were relatively high variation from 0.51 to 0.90, and physiological utilization efficiency was from 51.71 to 94.26. The high efficient group in nitrogen uptake efficiency whose value was calculated above 0.80 included Daeanbyeo, Seojinbyeo, Ansungbyeo, Dongjinbyeo, and Hwaanbyeo, while the low efficient group with below 0.60 was Kwanganbyeo, Sampyeongbyeo, Soorabyeo, and Hwasungbyeo. Hwasungbyeo, Sampyeongbyeo, Soorabyeo for physiological utilization efficiency were more efficient cultivars, while Daeanbyeo, Seojinbyeo, Ansungbyeo were less efficient cultivars. Nitrogen uptake efficiency had positive correlation coefficients between dry matter weight of plant (0.842** ), leaf area index (0.761** ), and leaf nitrogen content (0.599** ), respectively. Therefore, the dry matter weight of rice plant and leaf area index was important characters to evaluate nitrogen uptake efficiency in rice cultivars. Also, more efficient cultivar in nitrogen uptake had higher chlorophyll meter value, which was appeared dark green color.