Korea has experienced a rapid warming of 1.5℃during the last 100 years and even faster rise of air temperature is being projected in the future. This experiment was done to figure out the impact of the predidted temperature rise on the growth and yield of rice. Two rice varieties, "Hwaseongbyeo" and "Dasanbyeo" were grown in 1/5000a Wagner pot under the four plastic houses that were controlled to ambient, ambient+1.5℃, ambient+3℃ and ambient+5℃ throughout the rice growing season. Heading dates in the elevated temperature treatments were three to five days earlier than in the ambient temperature treatment. Rice growth was affected by temperature treatments differentially according to the tested cultivars. Hwaseongbyeo(japonica) showed significant reduction of shoot dry weight under ambient+5.0℃ treatment compared to the other treatments, while Dasanbyeo(tongil-type) showed significant increase of shoot and root dry weight under the elevated temperature treatments. The number of panicles per pot and spikelets per panicle and per pot was not significantly different among temperature treatments in both cultivars tested, but significantly lower grain yield was observed under the treatments raising the air temperature to the level of 3.0℃ and 5.0℃ above the ambient air temperature. This lower grain yield in the elevated temperature treatment of ambient+3℃ was attributed mainly to the decrease of grain weight due to the shortening of grain filling period, while the drastic yield reduction in the treatment of ambient+5℃ was caused not only by the lower grain weight but also by the marked increase in spikelet sterility due to the high temperature at meiotic and flowering stage. In conclusion, the ongoing global warming is expected to decrease the grain yield not only by decreasing the grain filling period in the near future but also increasing the spikelet sterility under the long-term projected climate of Korea.

This experiment was conducted to evaluate the effect of temperature rise on the phenological development and yield of oilseed rape in temperature-controlled plastic houses located at Suwon in 2008 and 2009. Two varieties "Halla" and "Naehan" were grown using 1/5000a Wagner pots in the three plastic houses greenhouses in which temperature was controlled to ambient temperature (AT), AT+1.5℃, and AT+3.0 through the growing season. Compared to the ambient temperature, leaf appearance was speeded up by temperature elevation, resulting in earlier flowering by 7 and 19 days at the treatments of AT+1.5℃and AT+3.0℃, respectively. YGrain yield was decreased by approximately 15% for each temperature elevation of 1.5 ℃. The yield decrease was attributed to the increased sterility and the decreased grain weight under the higher temperature conditio

Temperature rise of 4.0℃ is projected under SRES A1B greenhouse gases emission scenario in 2100 and this climate change is anticipated to affect the growth, phenological development, and yield of soybean. The objective of this experiment is to calibrate and validate CROPGRO_soybean model and evaluate the projected climatic change impact on soybean phenological development in Korea. For simulation experiment, four cultivars with different maturity groups, Hwaeomputkong(MG1), Sinpaldalkong(MG4), Taegwangkong(MG5), and Daewonkong(MG6) were calibrated and validated using data that were collected from the experiments of planting dates and daylength treatment. The calibrated model predicted the phenological stages with considerable accuracy for the data acquired independently of the calibration data. As global warming proceeds, days to flowering and days to physiological maturity on average across varietal groups and planting dates are anticipated to decrease by about 7 and 5 days respectively under the projected normal climate during the period of 2071~2100 compared to those under the current normal climate condition.

Plant leaf color is an important indicator for diagnosing the plant nutrient status. A software was developed by Crop Environment and Production Technology Lab. of Seoul National University to analyze the color image of rice canopy taken at panicle initiation stage (PIS) with digital camera and to recommend nitrogen fertilizer rate for target yield or protein content of rice. The software was coded in Visual Basic Ver. 6.0 and includes subroutine to calculate color indices from the digital image and several model equations relating the color indices to biomass and nitrogen accumulation of rice canopy at PIS, the grain yield to nitrogen density at PIS (PNup) and nitrogen accumulation from PIS to maturity (PHNup), and the PHNup to PNup and nitrogen fertilization rate at PIS. The objective of this study were to test the performance of the Software. Using the Software, nitrogen fertilization rate at PIS was recommended targeting the rice protein content of 6.3% for the 12 plots subjected to different amount of basal and tillering N fertilizer. N recommendation using the software reduced the coefficient of variation (CV, %) of rice yield and protein content among plots compared to the conventional N treatment plots. However, the actual protein content of rice was lower than the predicted value. This discrepancy would be attributable to the much better weather condition during grain filling period in 2009 compared to the normal year that assume in the Software for N recommendation. Additional calibration process is needed to improve the accuracy of this Software.

In order to investigate the genotypic variations of Zn accumulation in rice plant, thirty-five rice cultivars of different cultivar groups (temperate japonica, tropical japonica, tongil, and indica) were irrigated with irrigation water containing 2 ppm Zn throughout all growth season in a field experiments in 2007. At harvest, thirty-five rice cultivars showed large difference in Zn concentrations in root, shoot, straw, grain, chaff, brown rice, rice bran, and polished rice. Zn concentrations in polished rice ranged from 5.15 to 21.24 mg/kg. The total Zn accumulation in shoot varied from 12.18 to 54.84 mg/m2. Two japonica rice cultivar groups (temperate japonica, and tropical japonica) presented the higher Zn concentration in shoot compared to indica and Tongil cultivar groups. The large genotypic variation suggested the possibility of breeding low Zn accumulating rice varieties.

In the present experiment, thirty-five rice cultivars were irrigated by irrigation water containing 2 ppm Ni throughout all growth season in order to investigate the genotypic differences in Ni accumulation of rice. At harvest, thirty-five rice cultivars showed large difference in Ni concentrations in shoot, straw, grain, chaff, brown rice, rice bran, and polished rice, but not in root. Ni concentraions in polished rice ranged from 0.43 to 2.28 mg/kg. The total Ni accumulation of shoot varied from 0.63 to 2.93 mg/m2. Indica cultivar groups presented the highest Ni concentration of polished rice, but no significant difference from the other cultivar group. At the same time, indica cultivar group significantly accumulated more Ni by shoot compared to the other cultivar groups. The large genotypic variation suggested the possibility to breed low Ni accumulating rice cultivar.

In order to investigate the genotypic differences in Cu accumulation of rice, 35 rice cultivars of different cultivar groups (temperate japonica, tropical japonica, tongil, and indica) were cultivated in a field condition that rice was irrigated by irrigation water containing 2 ppm Cu throughout all growing season in 2007. Thirty-five rice cultivars showed large differences in Cu concentrations in all rice parts, including root, shoot, straw, grain, chaff, brown rice, rice bran, and polished rice. Cu concentrations in polished rice ranged from 0.78 to 2.84 mg/kg. The total Cu accumulation of shoot varied from 1.31 to 4.54 mg/m2. Indica and tongil cultivar groups presented the higher Cu concentration and accumulation comparing the two japonica rice cultivar groups (temperate japonica and tropical japonica). The large genotypic variation suggested the possibility of breeding low Cu accumulating rice cultivar.

Leaf color can be used as an indicator of the plant healthiness, and thus digital image analysis may provide farmers and researchers with time- and resource-saving methods for diagnosing plant nutrient status. The digital images are dependent on the ambient light, therefore the color indices of digital images should be compensated for the difference of ambient light. The objectives of this study were to develope the calibration methods for color indices under variable irradiance condition. Four color panels were used for RGB (Red, Green, Blue) values and color indices calibration purpose. Reflectance for each panel was measured by spectro-radiometer with a waveband range of 300 - 1100 nm. The reflectance values of four color panels was used as a reference for calibration of RGB values and color indices. Using digital camera color images were taken for rice canopies together with reference panel that was set up at the level of canopy surface. Digital images were obtained form rice fields with variable nitrogen fertilization managements at active tillering to panicle initiation stage. The calibration coefficients for color image indices were calculated by using the linear regression equation between the pixel values of color image for reference panel and their known reflectance values. The determination coefficients (r2) of linear regression between non-calibrated mean B values of plant pixels in color image and shoot nitrogen contents in four rice varieties, Odae, Hwasung, Chucheong, and Ilpum, was 0.30, 0.27, 0.37, and 0.27, respectively, while the respective r2 values were increased to 0.79, 0.85, 0.77, and 0.53.by applying the calibration coefficient. These results imply that color digital image analysis could be a promising method for diagnosing nitrogen nutrition status of rice canopy.