Global climate change accompanied by continuous increases in atmospheric carbon dioxide (CO 2) concentration and temperature affects the growth and yield of important crops. The present study investigated the effect of elevated temperature and CO 2 concentrations on the growth, yield, and photosynthesis of potato (Solanum tuberosum L. cv. Superior) crops using Korean Soil-Plant-Atmosphere-Research chambers that allow the regulation of temperature and CO 2 concentration under daylight conditions. Based on the average temperature from 1991 to 2010 in the Jeonju area, South Korea, potato plants were exposed to four different conditions: ambient weather (400 μmol mol-1 , aCaT), elevated temperature (+4˚C, aCeT), elevated CO 2 concentration (800 μmol mol-1 , eCaT), and concurrently elevated CO 2 concentration and temperature (eCeT). Under aCeT conditions, the temperature exceeded the optimal growth temperature range towards the late growth phase that decreased stomatal conductance and canopy net photosynthetic rate and subsequently reduced biomass and tuber yield. Stomatal conductance and chlorophyll concentration were lower under eCaT conditions than under aCaT conditions, whereas late-growth phase biomass and tuber yield were greater. Compared to other conditions, eCeT yielded a distinct increase in growth and development and canopy net photosynthetic rate during tuber initiation and bulking. Consequently, biomass and canopy net photosynthesis increased, and tuber yield increased by 20.3%, which could be attributed to the increased tuber size, rather than increased tuber number. Elevated CO 2 reduced chlorophyll, magnesium, and phosphorus concentrations; reducing nitrogen concentration (by approximately 39.7%) increased the C: N ratio. The data indicate that future climate conditions will likely change nutrient concentration and quality of crops. The present study shows that while elevated temperature may negatively influence the growth and yield of potato crops, especially towards the late-growth phase, the concurrent and appropriate elevation of CO 2 and temperature could promote balanced development of source and sink organs and positively effect potato productivity and quality.

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The green manure crops are returned to soil when the plants are still green. The green manure crops play a role in reducing chemical fertilizers, improvement of soil fertility, reduction of soil erosion, weed control, and landscapes effect. Typical green manure crops are barley green manure, hairy vetch, chines milk vetch and clovers. We sowed 49 species of green manure crops in upland soil to increase the usage of green manure crops. We searched the effectiveness of green manure yield, C/N ratio, soil mulching, and landscape effect. The green manure crops that have 5 ton ha -1 or more of green manure yield (fresh weight) were 6 gramineous crops, 4 leguminous crops, and 3 others. Green manures yield in a short growth period was higher in gramineous crops than leguminous crops. Among the green manure crops, 3 gramineous crops, 12 leguminous crops, and 3 others were under 25 in C/N ratio. Seven gramineous crops, 8 leguminous crops, and 5 others were over 50% of soil covering rate. Green manure crops that have beautiful flowers were in total 16 kinds, such as 4 gramineous crops, 6 leguminous crops, and 6 others. In result, based on green manure yield and C/N ratio, excellent species in the green manure crops were 4 species (triticale, 2 kinds of hairy vetch, and lupin). Green manure crops that were effective at soil mulching were 20 species, like hairy vetch, oats, sorghum, phacelia, buckwheat, etc. Buckwheat, crotalaria, mustard plant, phacelia, and etc. could be available for landscape crops.

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Organic matter is a substance that contains carbon. When applied to soil, it can improve the physical and chemical properties of soil and supply nutrients to plants. Also, it is decomposed in soil due to microbe activity, or absorbed and utilized by crops. The remaining differential to materials is accumulated in the soil and increases the level of organic matter in soil. Given that the humidity and temperature are appropriate, and there are energy sources favorable for microbe activity, the decomposition rate is higher, thus resulting in the increase of the nutrient availability of crops. Therefore, we analyzed the types of carbon content according to time while cultivating beans in soil with 4 different kinds of organic matter applied. Total carbon content (TC) was higher in organic matter application than in control (non-organic matter). Among the other organic matters, it was especially high in livestock manure compost (LMC) application with 11.1 g kg -1 . Hairy vetch (HV, 8.9 g kg -1 ), oil cake (OC, 8.9 g kg -1 ), and rice straw (RS, 8.2 g kg -1 ) did similar. According to soil carbon form, Humin carbon(HnC) had the highest total carbon contrast of 62.0 %, Humic acid carbon(HaC) had 19.6%, and Fulvic acid carbon(FaC) had 18.1%. This pattern was the same in both control and organic matter application. Every type of carbon was the highest in LMC application. TC levels were temporarily high in June, which was after organic matter application, and decreased. It was higher than any other organic matter application in LMC. HaC increased in May and June which was when the organic matter was applied, slightly decreased in July, and were the highest in LMC with TC. FaC slowly increased after organic matter application until March and slowly decreased afterwards. It was highest in LMC, and similar in HV, OC, and RC, which shows that it had the smallest difference of content between kinds of organic matter. HnC inclined to decrease slowly as time passed after organic matter application, but rapidly increased in July and June. Also, it was the highest in LMC, and similar in HV, OC, and RC. Therefore, it was concluded that LMC, which had a high level of humin carbon that is difficult to decompose, was the best for accumulating carbon in soil.