The effects of CO2 enrichment on growth of maize (Zea mays L.) were examined. Parameters analyzed include growth characteristics, yields, photosynthetic rates, evaporation rates and photosynthesis-related characteristics under elevated CO2 . The plants were grown in growth chambers with a 12-h photoperiod and a day/night temperature of 28/21~circC at the seedling stage and 30/23~circC from the silking stage. The plants were exposed to two elevated CO2 of 500, 700ppm and ambient levels (350 ppm). Chalok 1 and GCB 70 germinated three days after seeding, and germination rates were faster in the elevated CO2 than the control. Germination rates displayed significant differences among the CO2 treatments. At the seedling stage, leaf area, top dry weight, and photosynthetic rates, and plant height indicated positive relationship with elevated CO2 concentrations. At the 5~6 leaf stage, CO2 concentration also indicated positive relationship with plant height, leaf area, top dry weight, and photosynthetic rates. At the silking stage, increased plant height of Chalok 1 was noted in the CO2 treatments compared to the control. No significant differences were noted for GCB 70, in which leaf area decreased but photosynthetic rates increased progressively with CO2 concentration. Stomatal aperture was a little bigger in the elevated CO2 than the control. CO2 concentration was negatively related to stomatal conductance and transpiration rates, resulting in high water use efficiency.

대기중의 CO2 농도 증가에 따른 벼의 생육단계별 생육 및 광합성 관련 반응을 관찰한 결과는 다음과 같았다. 1. 벼 유묘기에는 CO2 농도가 증가하고 처리기간이 길어질수록 일품벼, 추청벼, 화성벼 모두 초장, 경수, 엽면적이 증가하였고 처리 후 18일경에는 대비구에 비해 500ppm, 700ppm에서 건물중 35~~47~% 증가하는 경향이었다(3품종 평균). 2. 벼 유모기의 광합성율은 높은 CO2 >농도에서는 증가되었으나 처리기간이 길어져서 생육이 진전될수록 약간 감소하는 경향이었다. 3. 유수형성기 및 출수기에는 CO2 농도가 증가함에 따라 초장, 건물 중은 증가되었으나 SPAD값과 광합성속도, 기공전도도, 증산율 등은 처리기간이 길어질수록 감소하였다. 4. 출수 직전부터 55일간 처리한 벼의 수량은 대비구에 비해 500ppm, 700ppm 처리구에서 세 품종 모두 큰 차이가 없었다. 5. CO2 농도에 따른 광합성 속도 및 증산량은 농도가 높아지고 광합성속도가 빨라질수록 증산량은 낮아져 수분 이용 효율이 높은 것으로 나타났다.