Climate warming has the potential to deteriorate grain yield and quality of rice (Oryza sativa L.), offsetting the stimulative effects of elevating CO2. To know how the change in sink-source balances by reducing sink-size (RSS) may affect grain yield and quality of rice grown under various climate change scenarios, we conducted a temperature gradient chamber experiment with/without CO2 fumigation systems which were established in paddy field. Rice crops (cv. Ilmybyeo) were exposed to either ambient (396ppmV) or elevated CO2 of 673ppmV in three levels of air temperature [(Ta), local ambient Ta (24.8℃), 1.3℃ and 2.4℃ above ambient Ta] over whole seasons. Thus, the experiment was a 2×3 factorial design with three replicate plots of each CO2×Ta combination. At flowering, for two hills from each combination treatment total thirty (10 per each top, middle and basal parts of panicle) spikelets per panicle were removed with order of panicle appearance by scissors. This corresponded to a 25% reduction of total sink-size per hill. In ambient Ta and CO2 , grain yield decreased with RSS by 23.4%, approximately mirroring the reduced sink-size. With rising Ta, however, the yield reduction by RSS was significantly mitigated (-5.6% in 1.3℃ above ambient Ta), and the yield rather increased with RSS by 9.3% in 2.4℃ above ambient Ta. This was due primarily to the increased single grain mass with RSS. A similar response fashion of grain mass and yield with RSS to Ta was found in elevated CO2, but not CO2×Ta interaction. For brown rice, the fraction of normal rice was linearly reduced with rising Ta, ranging from 78.5～79.2% in local ambient Ta to 48.2～55.5% in 2.4℃ above ambient Ta over CO2 treatments. However, this deteriorative effect of rising Ta was significantly alleviated with RSS; the fractions of normal rice were a 81.9～84.1%, 75.9～77.2% and 64.0～66.3% in local ambient Ta, 1.3℃ and 2.4℃ above ambient Ta, respectively. The alleviative effect of RSS on rice quality was due mainly to the reduced immature rice, and was more conspicuous as Ta rises. These results suggest that current rice cultivars in Korea, at least cultivars tested in this experiment, will likely to be prone to source-limitation in the future projected warming with elevating CO2, and thereby will be needed a cultivar having either a greater source ability or a less sink size compared with current cultivars, in order to ensure a rice quality in the future warming conditions.

To know how interacting climate drivers may affect rice quality, we investigated physio-chemical properties of brown and milled rice. Rice crops (Oryza sativa L., cv. Ilmybyeo and Pyounganbyeo) were grown under either ambient [370ppmV (2008)/396ppmV (2009)] or elevated CO2 of 650ppmV (2008)/673ppmV (2009) in three levels of air temperature [(Ta), local ambient Ta [25.9℃ (2008)/24.8℃ (2009)], 1.3℃ and 2.4℃ above ambient Ta] over whole seasons, using six temperature gradient chambers established in paddy fields. Over 2 years, thus the experiments were a 2×3 factorial design with three replicate plots of each CO2×Ta combination. The fractions of normal brown rice were reduced with elevating CO2 by 8% (Ilmybyeo)～14% (Pyounganbyeo), and with rising Ta by 16% (+1.3 ℃)～27% (+2.4℃) in Ilmybyeo and by 27% (+1.3℃)～42% (+2.4℃) in Pyounganbyeo (p=0.015, 0.000, 0.059, 0.000 and 0.017 for CO2, Ta, CO2×Ta, cultivar and Ta×cultivar, respectively). With respect to immature rice, elevating CO2 increased milky-white rice, white-based rice and white-belly rice across cultivars. Warming also significantly increased all immature rice across cultivars, though no CO2×Ta interaction was observed. Over 2 years, the deteriorative effect of warming on brown rice quality was significantly greater in Pyounganbyeo than in Ilmybyeo. Across cultivars, protein contents of milled rice were decreased (c. 5～9%) with elevating CO2 but increased (c. 5%) with warming, though no CO2×Ta interaction was found (p=0.119). Elevating CO2 significantly increased whiteness of milled rice over cultivars but not amylose contents and gloss value of cooked rice, while warming had a strong affect these properties all related rice quality. Overall, our results suggest that warming and elevating CO2, in each alone or in combination, may have the potential to deteriorate physio-chemical properties of rice related to quality.

This paper was studied CO2 respiration rate with physicochemical properties of soils at wetland, paddy field and forest in Nongju-ri, Haeryong-myeon, Suncheon city, Jeollanam-do. Soil temperature and CO2 respiration rate were measured at the field, and soil pH, moisture and soil organic carbon were analyzed in laboratory. Field monitoring was conducted at 6 points (W3, W7, W13, W17, W23, W27) for wetland, 3 points (P1, P2, P3) for paddy field and 3 points (F1, F2, F3) for forest in 10 January 2009. CO2 concentrations in chamber were measured 352∼382 ppm for wetland, 364∼382 ppm for paddy field and 379∼390 ppm for forest, and the average values were 370 ppm, 370 ppm and 385 ppm, respectively. CO2 respiration rates of soils were measured -73∼44 mg/㎡/hr for wetland, -74∼24 mg/㎡/hr for paddy field and -55∼106 mg/㎡/hr for forest, and the average values were -8 mg/㎡/hr, -25 mg/㎡/hr and 38 mg/㎡/hr. CO2 was uptake from air to soil in wetland and paddy field, but it was emission from soil to air in forest. CO2 respiration rate function in uptake condition increased exponential and linear as soil temperature and soil organic carbon. But, it in emission condition decreased linear as soil temperature and soil organic carbon. CO2 respiration rate function in wetland decreased linear as soil moisture, but its in paddy and forest increased linear as soil moisture. CO2 respiration rate function in all sites increased linear as soil pH, and increasing rate at forest was highest.

일반적으로 일반대기중의 CO2 농도는 낮기 때문에 자연상태에서는 중성화정도는 매우 느리게 된다. 따라서 콘크리트의 중성화 정도를 평가하기 위해서는 일반적으로 진행속도를 빠르게 하기 위하여 촉진 시험조건하에서 진행하게 된다. 따라서 본 논문은 CO2의 확산 및 Ca(OH)2와의 반응을 바탕으로한 수학적 모델을 통하여 일반대기환경하에서의 콘크리트 중성화 진행을 예측하고자 한다. 이를 위하여 본 논문에서는 촉진 중성화시험을 통하여 얻어진 실험치와 가장 유사한 CO2 확산계수를 채택하여 일반대기환경에서의 중성화진행을 예측하고자 하였다. 그 결과 CO2 확산계수를 이용한 수학적 모델을 통하여 마감재 종류에 관계없이 일반대기환경에서의 콘크리트 중성화진행속도를 예측할 수 있었다.

황기의 자가불화합성 타파를 위한 노화수분 처리, NaCl 처리 및 CO2 처리에 대한 결과를 요약하면 다음과 같다. 비닐하우스에서 노화수분은 8월 하순에는 거의 수정이 되지 않았으며, 9월 상순부터 10월 상순까지는 개화 당일 부터 개화 후 2일까지 수정되었고, 9월 하순 개화 당일 수분한 것이 결협율 33.3%, 결실율 86.2%로 가장 양호하였다. 노지에서 노화수분은 대조구는 8월 하순부터 10월 상순까지 결협은 되었으나, 9월 중순과 9월 하순을 제외하고 결실이 되지 않았으며, 9월 하순의 개화 후 1일에 결협율 39%, 결실율 94.9%로 가장 양호하였다. NaCl 처리는 비닐하우스에서는 1% 농도 처리가 결협율은 10월에서 21.3%로 가장 좋았으나, 결실율은 9월 하순 66.7%로 가장 양호 하였고, 노지에서는 NaCl 농도 5%에서 결협율 7.3%, 결실율 90.9%로 가장 양호하였다. 식물생육상을 이용하여 CO2 700 ppm을 처리한 결과 무처리구와 큰 차이 없었다. 결론적으로 황기 자가불화합성 타파를 위하여 9월 중하순에 자화가 아닌 자가화를 개화당일 또는 개화 후 1일에 인공수분해주거나 NaCl 1~5%를 처리해주면 자가불화합성을 타파할 수 있다고 사료된다.

Changing climate, especially water content(WC) and CO2 (CD) concentration could be effect on the growth of soybean and seed yield. So we evaluated the effects of WC and CD on the physiological characteristics of newly developed soy cultivars in growth chamber. Ten soy cultivars evaluated in three [CO2] levels (CD1, 350; CD2, 500; CD3, 700ppm) and three water content (WC1: 30%, WC2: 40, WC3: 50%) in the pot in growth chamber. Increased [CO2] from 350 to 500 and 500 to 700ppm enhanced crop growth parameters greatly and grain yield, however, grown in CD3 enhanced plant height increasing speed, and shortened growing duration, however, they were grow very weakly and it resulted in lodging problem. High soil water content (WC3) hampered growth and yield of soybean in three CD treatments and the degree was lower in CD1 and CD2 than CD3. In this results we can conclude increasing [CO2] in Korean peninsular might be decrease lodging resistance, especially high moisture content, so, plant breeders and physiologists need to develop improved lodging resistance cultivars under high water content and high CO2 content.