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Various methods for assessing soil total nitrogen (TN) and inorganic N content have been developed to manage nutrient and to understand N cycle in soil. This paper address the technical procedures in arable soil samples to conduct soil sampling, sample preparation, and measuring total N and inorganic N. Among various methods for measuring soil total nitrogen contents, Kjeldahl distillation and Indophenol blue method have widely used due to reliability and economic advances. Also, two methods can analyze more samples at the same time compared with other nitrogen measuring methods. For evaluating inorganic N content, mainly in forms of nitrate-N (NO₃ - -N) and ammonium-N (NH₄ + -N), extraction with a single reagent such as 2M KCl has been employed, followed by Kjeldahl distillation or indophenol blue methods.

An estimation of optimal requirement of additional N by cropping pattern and growth stage is very important for greenhouse watermelon. The objectives of this study were to estimate an amount of optimal additional N based on growth, N uptake and yield of watermelon. In order to achieve these goals, we performed the study at farmer’s greenhouse with a fertigation system and watermelon was cultivated three times (spring, summer and autumn) in 2015. The levels of additional N were set up with x0.5, x0.75, x1.0 and x1.5 of the NO₃-N-based soil-testing N supply for watermelon cultivation. The trends of growth and N uptake of watermelon markedly differed from cropping pattern; spring (sigmoid), summer and autumn (linear). The yield of watermelon was the highest at summer season and followed by autumn and spring. Also, the x1.5N showed a significantly higher yield compared to other N treatments. On the basis of growth, N uptake and yield of watermelon, we estimated an optimal level of additional N by cropping pattern and growth stage as follows; 1) spring (transplanting ~ 6 WAT : 6 ~ 14 WAT : 14 ~ harvest = 5 : 90 : 5%), summer (transplanting ~ 4 WAT : 4 ~ 8 WAT : 8 ~ harvest = 25 : 50 : 25%) and autumn (transplanting ~ 4 WAT : 4 ~ harvesting : 50 : 50%). In conclusion, nutrient management, especially N, based on cropping pattern and growth stage was effective for favorable growth and yield of watermelon.

Excessive nitrogen fertilization influences crop yields and quality as well as environmental pollution. In this study, yields, nitrogen use efficiency and free sugar contents of burdock (Arctium lappa L.) were evaluated at different levels of nitrogen fertilization. Nitrogen fertilizer was applied at 5 levels (0, 50, 100, 150, 200%) based on the conventional fertilization (N = 230 kg ha -1 ), and phosphate and potassium fertilizer were treated by conventional P and K fertilization (P₂O 5 - K₂O = 140 - 210 kg ha -1 ) in all plots. The root yields of burdock were the highest in N 100~150% treatment plots. Nitrogen use efficiency and nitrogen recovery decreased from over N 150% treatment. Nitrogen uptake of root was greater than that of shoot in N 50~200% treatments. Fructose contents in root were inversely proportional to the level of nitrogen fertilization. As considering nitrogen recovery and root quality, economical burdock yield was obtained in N 230 kg ha -1 .

Specific metabolic network responses to mineral starvation are not well-defined. We examined a detailed broad-scale identification of metabolic responses of tomato leaf and root to N, P or K starvation. Tomato plants were grown hydroponically under optimal (5 mM N, 0.5 mM P, or 5 mM K) and starved (0.5 mM N, 0.05 mM P, or 0.5 mM K) conditions and metabolites were measured by LC-MS and GC-MS. Overall, the levels of metabolites (lipids, nucleotides, peptides and secondary metabolites) presented in this paper largely showed mineral- and tissue-specific responses. Most strikingly, G3P (glycerol-3-P), GPC (glycerol-P-choline) and choline phosphate responded differently to a type of mineral; an increase in N or K starvation and a decrease in P starvation. A dramatic increase in the levels of secondary metabolites, in particular, rutin and chlorogenate in both tomato tissues during N starvation were observed. Based on these data, it is necessary to clearly elucidate an unknown event taking place in a variety of abiotic impacts, and we are now studying to expand our knowledge on metabolic- and proteomic-responses using GS-MS and LC-MS.

With increasing social concerns for healthy food, the studies on the cultivation of crops to increase accumulation of functional metabolites in crops have been investigated. Accumulation of the metabolites in crops is highly affected by various types of stress, such as nutrient deficiency, water deficit (WD), extreme temperature and UV-B radiation as well as their own life cycle. This review summarizes the previous studies on the effects of environmental stresses, especially WD and UV-B radiation, on accumulation of functional metabolites in crops. UV-B radiation and WD during specific period (mainly at maturation stage) activates the adaptation and/or defense system in crops, thereby increasing biosynthesis of the metabolites. Although WD and UV-B radiation tend to decrease in crop yield, the decrease can be compensated by the production of high value crops having high content of functional metabolites.

The objectives of fertilizer recommendation are to prevent the application of excessive fertilization and to produce target yields. Also, optimal fertilization is important because crop quality can be influenced by fertilization. In this study, yields and fertilizer use efficiency of Taro (Colocasia esculenta Schott) were evaluated in different level of NPK fertilization. N, P and K fertilizer application rates were 5 levels (0, 50, 100, 150, 200%) by practical fertilization (N-P₂O 5 -K₂O = 180-100-150 kg ha -1 ), respectively. In the N treatment, the yields of Taro tuber were about 33 Mg ha-1 from 90 to 360 kg ha -1 N fertilization. However, the ratio of tuber to total biomass decreased with increasing N fertilization rate. In the P and K treatments, yields of Taro tuber were the highest at 150 kg ha -1 fertilization. Fertilizer use efficiency was decreased by increase of N and K fertilization. Crude protein of Taro tuber was the highest at practical fertilization. Sucrose content of tuber was influenced by phosphate application.

Soil testing is one of the major strategies for establishing sustainable agricultural practice as it analyzes nutrient contents of soil and determines the amount of nutrients required for crop growth. Soil testing for the field cultivating regional major crops in Korea has been conducting by National Academy of Agricultural Science (NAAS), provincial agricultural research & extension services and agriculture technology centers since 2000. 1,006,227 soil samples were analyzed and uploaded on Korean soil information system (http://soil.rda.go.kr) from 2003 to 2013. Soil pH has changed from 6.1 to 6.2. Organic matter (OM), available (Avail.) phosphate and exchangeable (Exch.) K have decreased from 24 to 23 g kg -1 , 541 to 399 mg kg -1 and 0.90 to 0.72 cmolc kg -1 between 2003 and 2013, respectively. Especially, Exch. Ca contents decreased to 5.7 cmolc kg -1 in 2009 and increased to 6.2 cmolc kg -1 in 2013. Ratios of optimal ranges for cropping were 48% for pH, 22% for OM, 26% for Avail. phosphate, and 23, 16, 22% for Exch. K, Ca and Mg in 2013. Ratios of optimal ranges for pH increased and low ranges for OM, Avail. phosphate and Exch. K increased. Frequency distribution was 64% for pH 5.5~7.0, 65% for OM 10~30 g kg -1 , 48% for Avail. phosphate under 300 mg kg -1 and 23, 29, 22% for Exch. K 0.2~0.6, Ca 4.0~6.0 and Mg 1.0~1.5 cmolc kg -1 .

Heavy metals reduce the photosynthetic efficiency and disrupt metabolic reactions in a concentrationdependent manner. Moreover, by replacing the metal ions in metalloproteins that use essential metal ions, such as Cu, Zn, Mn, and Fe, as co-factors, heavy metals ultimately lead to the formation of reactive oxygen species (ROS). These, in turn, cause destruction of the cell membrane through lipid peroxidation, and eventually cause the plant to necrosis. Given the aforementioned factors, this study was aimed to understand the physiological responses of rice to cadmium (Cd) and arsenic (As) toxicity and the effect of essential metal ions on homeostasis. In order to confirm the level of physiological inhibition caused by heavy metal toxicity, hydroponically grown rice (Oryza sativa L. cv. Dongjin) plants were exposed with 0-50 μM cadmium (Cd, CdCl₂) and arsenic (As, NaAsO₂) at 3-leaf stage, and then investigated malondialdehyde (MDA) contents after 7 days of the treatment. With increasing concentrations of Cd and As, the MDA content in leaf blade and root increased with a consistent trend. At 14 days after treatment with 30 μM Cd and As, plant height showed no significant difference between Cd and As, with an identical reduction. However, As caused a greater decline than Cd for shoot fresh weight, dry weight, and water content. The largest amounts of Cd and As were found in the roots and also observed a large amount of transport to the leaf sheath. Interestingly, in terms of Cd transfer to the shoot parts of the plant, it was only transported to upper leaf blades, and we did not detect any Cd in lower leaf blades. However, As was transferred to a greater level in lower leaf blades than in upper leaf blades. In the roots, Cd inhibited Zn absorption, while As inhibited Cu uptake. Furthermore, in the leaf sheath, while Cd and As treatments caused no change in Cu homeostasis, they had an antagonist effect on the absorption of Zn. Finally, in both upper and lower leaf blades, Cd and As toxicity was found to inhibit absorption of both Cu and Zn. Based on these results, it would be considered that heavy metal toxicity causes an increase in lipid peroxidation. This, in turn, leads to damage to the conductive tissue connecting the roots, leaf sheath, and leaf blades, which results in a reduction in water content and causes several physiological alterations. Furthermore, by disrupting homeostasis of the essential metal ions, Cu and Zn, this causes complete heavy metal toxicity.

Crop yields depend on the limiting factor of crop growth; Liebig law of minimum. Identifying the kind and the necessary amount of the limiting factor is essential to increase crop yield. Although nitrogen is the most essential nutrient, N application does not always bring about yield increases when other elements are limiting in rice cultivation. Two experiments were compared to elucidate the effect of soil testing on rice yield response to N level. The one was an experiment about yield response of 3 rice cultivars to 7 levels of N application, which was conducted from 2003 to 2004 in 25 farmer’s fields without ameliorating soil conditions by soil testing and the other was a demonstration experiment on N fertilizer recommendation equation by 0, 0.5, 1.0, and 1.5 times of N recommended level in 5 soil types from 30 fields after ameliorating soil conditions by soil testing. The N response patterns of the experiments conducted without soil testing showed a Mitscherlich pattern in some cultivars and soil types, but did not in the others. The N response patterns of the demonstration experiment showed a Mitscherlich pattern in all soil types. Because these results indicated that N was the minimum nutrient in the demonstration experiment by ameliorating soil conditions with soil testing, but not in the other experiment without soil testing, the supply of minimum nutrients by soil testing could increase the efficiency of N-fertilization.

This study was carried out to find out major factors to mitigate carbon emission using Life Cycle Assessment (LCA). System boundary of LCA was confined from sowing to packaging during vegetable production. Input amount of agri-materials was calculated on 2007 Income reference of white radish, chinese cabbage and chive produced at open field and film house published by Rural Development Administration. Domestic data and Ecoinvent data were used for emission factors of each agri-material based on the 1996 IPCC guideline. Carbon footprint of white radish was 0.19 kg CO₂ kg -1 at open fields, 0.133 kg CO₂ kg -1 at film house, that of chinese cabbage was 0.22 kg CO₂ kg -1 at open fields, 0.19 kg CO₂ kg -1 at film house, and that of chive was 0.66 kg CO₂ kg -1 at open fields and 1.04 kg CO₂ kg -1 at film house. The high carbon footprint of chive was related to lower vegetable production and higher fuel usage as compared to white radish and Chinese cabbage. The mean proportion of carbon emission was 35.7% during the manufacturing byproduct fertilizer; white radish at open fields was 50.6%, white radish at film house 13.1%, Chinese cabbage at outdoor 38.4%, Chinese cabbage at film house 34.0%, chive at outdoor 50.6%, and chive at film house 36.0%. Carbon emission, on average, for the step of manufacturing and combustion accounted for 16.1% of the total emission; white radish at open fields was 4.3%, white radish at film house 15.6%, Chinese cabbage at open fields 6.9%, Chinese cabbage at film house 19.0%, chive at open fields 12.5%, and chive at film house 29.1%. On the while, mean proportion of carbon footprint for the step of N₂O emission was 29.2%; white radish at open fields was 39.2%, white radish at film house 41.9%, Chinese cabbage at open fields 34.4%, Chinese cabbage at film house 23.1%, chive at open fields 28.8%, and chive at film house 17.1%. Fertilizer was the primary factor and fuel was the secondary factor for carbon emission among the vegetables of this study. It was suggested to use Heug-To-Ram web-service system, http://soil.rda.go.kr, for the scientific fertilization based on soil testing, and for increase of energy efficiency to produce low carbon vegetable.

The steady increase in livestock industry has greatly required the stable production of food and forage crops. As an alternative, rice-forage cropping system has been attempted in several southern areas. The present study was performed to understand whether an application of cattle-manure compost affects soil chemical properties and crop productivity in rice-forage cropping system, rice → summer oat → rye, in Jangheong county, south Jeolla province from 2013 to 2014. Treatments was composed of control (no compost), CM1 (compost application before rice transplanting), and CM2 (two-times compost application, before rice transplanting and after rice harvest), and inorganic fertilizers (N, P, and K) were equally dressed in all plots. Yields of rice were not significantly different between treatments, however, oat production was 1.25-fold higher in CM1 and CM2. Nutrient uptake amounts of rye were higher in CM2 than CM1 and control. Total nitrogen in soil was maintained stable level during crop cultivation. And soil organic matter contents in all treatments were increased by crop residue. Available P₂O 5 and exchangeable K were increased by cattle manure application. Therefore, it suggested that the amount of nutrient by forage crop residue should be considered in rice-forage multiple cultivation.

An accurate analysis of nutrient balance in different cropping systems is necessary for improving soil fertilities, causing higher crop yields and quality. This study was carried out to investigate the nutrient balance, changes in soil properties, and their effects on crop yield in long-term field cultivation under mono- and rotation-cropping systems (MCS and RCS, respectively). The analytical results of the soil properties showed that the application of mineral fertilizers alone in the MCS leads the reduction of soil CEC, exchangeable Ca, and microbial biomass C and N. Compared with the MCS of soybean, the RCS of soybean and barley significantly improved the soil properties, which increased crop yield. It might be due to the barley residue added to the RCS soil. Mean nutrient balances for 4 years were ?55.9 kg N, +34.7 kg P₂O?, and ?0.3 kg K₂O ha -1 for the MCS and +19.7 kg N, +107.4 kg P₂O?, and ?48.6 kg K₂O ha -1 for the RCS, respectively. These nutrient imbalances mean that conventional fertilizer recommendations were inadequate for maintaining soil nutrient balance. From these results, we can conclude that the crop rotation may change comprehensive physical, chemical, and biological soil properties. These changes could affect the nutrient balance and then the crop yield.

Chemical properties of agricultural soils in Korea have been investigated at four-year interval in order of paddy, polytunnel, upland, and orchard soils since 1999; polytunnel soils were investigated over the whole country in 2000, 2004, 2008, and 2012. Polytunnel soils were taken from the surface (0-15 cm) and subsurface (15-30 cm) at 2,651, 1,274, 1,374 and 1,374 sites in all provinces of South Korea. One hundred sampling sites located in more than 400 m altitude were additionally investigated in 2008 and 2012. Average of soil chemical properties in 2012 except Jeju province were 6.6 for pH, 3.2 dS m -1 for EC, 37 g kg -1 for organic matter (OM), 1,049 mg kg -1 for available (Avail.) phosphate, 1.58 cmolc kg -1 for exchangeable (Exch.) K, 10.6 cmolc kg -1 for Exch. Ca, and 3.3 cmolc kg -1 for Exch. Mg. Except pH, averages of all chemical properties exceeded the upper limit of optimal range. The median values except pH showed a lower value than the averages. The pH, OM and Exch. Ca had slightly increased from 6.3 to 6.6, from 34 to 37 g kg -1 , and from 7.7 in 2000 to 10.6 cmolc kg -1 in 2012, respectively. The order of sample ratios exceeding the optimal range were Avail. P2O5 (83%) > Exch. Ca (80%) > Exch. K (70%) > Exch. Mg (65%) > EC (55%) > OM (48%) > pH (29%) in 2012. The order of sample ratios below the optimal range was OM (25%) > Exch. K (25%) > pH (20%), Exch. Mg and Avail. P2O5 (9%) > Exch. Ca (6%) in 2012. The excessive proportion of pH, Exch. Ca, Exch. Mg and OM slightly increased, while the insufficient proportion of those decreased. Approximately 55% of polytunnel soils exceeding EC 2 dS m -1 was evaluated with salt accumulated soils having the risk of growth disorder of crops. Nutrient contents in polytunnel soils in Korea showed high level especially Avail. P₂O? and Exch. cations. Therefore, recommended fertilization based on soil testing or plant testing is needed for soil nutrient management.

The objective of this study was to establish the decision criteria of soil suitability for Korean Black raspberry using soil morphological and physical properties. The investigation was carried out in Gochang, Sunchang, Jeongeup, Pohang, and Hoengseong districts in Korea. The obtained results showed that factors related to the decision criteria of the soil suitability for Korean Black raspberry cultivation were soil texture, soil drainage class, land slope, and available soil depth . The criteria of the best suitability soil for Korean Black raspberry was valley/fan or hill geomorphology, well or moderately drainage class, B-slope(2-7%), coarse loamy soil texture family, less than

This study was conducted to assess emissions in agricultural soils of Korea. According to 1996 and 2006 IPCC (Intergovernmental Panel on Climate Change) methodology, emission was calculated the sum of direct emission () and indirect emission (). To calculate emissions, emission factor was used default of IPCC and activity data was used the food, agricultural, forestry and fisheries statistical yearbook of MIFAFF (Ministry for Food, Agriculture, Forestry and Fisheries). It was emitted 8,608 Mg resulted from direct emission by application of chemical fertilizer and animal manure, input in n-fixation crops and input of crop residues and emissions converted into equivalent was 2,668 -eq Gg. Indirect emission as (atmospheric deposition of and ) and (leaching and runoffs) were 4,567 and 6,013 Mg and emissions converted into equivalent were 1,416 and 1,864 -eq Gg, respectively. Total emission in Korea agricultural soil in 2009 was 5,948 -eq Gg.

Korea is currently underway research to estimate carbon footprint in agriculture centered on the RDA (Rural Development Administration). This study was estimated carbon footprint for major 47 crops. In addition, contribution of inorganic chemical fertilizers, main elements for production of crops were analyzed. The carbon footprint of for citrus fruit in greenhouse was highest, grape in greenhouse, sweet pepper in greenhouse, ginseng, green pepper in greenhouse were followed by , , , respectively. Next, production phase contribution of inorganic chemical fertilizer to carbon footprint of crop 1 kg were analyzed mean value 1.88%, 9.06% for single fertilizers and complex fertilizers respectively. And use phase accounted for mean value 14.24%. Therefore, to reduce the fertilization of inorganic chemical fertilizer will be reduced from crop production, also greenhouse gas emissions of agricultural sector will be reduced.

This study was carried out to estimate carbon emission using LCA (Life Cycle Assessment) and to establish LCI (Life Cycle inventory) DB for lettuce production system in protected cultivation. The results of data collection for establishing LCI DB showed that the amount of fertilizer input for 1 kg lettuce production was the highest. The amounts of organic and chemical fertilizer input for 1 kg lettuce production were 7.85E-01 kg and 4.42E-02 kg, respectively. Both inputs of fertilizer and energy accounted for the largest share. The amount of field emission for CO2, CH4 and N2O for 1 kg lettuce production was 3.23E-02 kg. The result of LCI analysis focused on GHG (Greenhouse gas) showed that the emission value to produce 1 kg of lettuce was 8.65E-01 kg CO2. The emission values of CH4 and N2O to produce 1 kg of lettuce were 8.59E-03 kg CH4 and 2.90E-04 kg N2O, respectively. Fertilizer production process contributed most to GHG emission. Whereas, the amount of emitted nitrous oxide was the most during lettuce cropping stage due to nitrogen fertilization. When GHG was calculated in CO2-equivalents, the carbon footprint from GHG was 1.14E-+00 kg CO2-eq. kg -1 . Here, CO2 accounted for 76% of the total GHG emissions from lettuce production system. Methane and nitrous oxide held 16%, 8% of it, respectively. The results of LCIA (Life Cycle Impact assessment) showed that GWP (Global Warming Potential) and POCP (Photochemical Ozon Creation Potential) were 1.14E+00 kg CO2-eq. kg -1 and 9.45E-05 kg C2H4-eq. kg -1 , respectively. Fertilizer production is the greatest contributor to the environmental impact, followed by energy production and agricultural material production.

Anaerobic decomposition of organic materials in flooded rice fields produces methane () gas, which escapes to the atmosphere primarily by transport through organs of the rice plants such as arenchyma etc., Although the annual amount of methane emitted from a given area is influenced by cultivation periods of rice and organic/inorganic amendments etc., soil type also affects methane emission from paddy soil during a rice cultivation. A field experiment was conducted to evaluate effects of soil type on emission in two paddy soils. One is a red-yellow soil classified as a Hwadong series (fine, mixed, mesic family of Aquic Hapludalfs), and the other is a gley soil classified as a Shinheung series (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentic Endoaquepts). During a flooded periods, redox potentials of red-yellow soil were significantly higher than gley soil. emission in red-yellow soil () was lower than that in gley soil (). In the condition of different soil types, emissions were mainly influenced by the content of total free metal oxides in paddy soil. The results strongly imply that iron- or manganese-oxides of well ordered crystalline forms in soil such as goethite and hematite influenced on a emission, which is crucial role as a oxidizers in paddy soil during a rice cultivation.

기후변화 대응 기술개발, 온실가스 저감계획 수립과 정책개발 등 기후변화에 효율적으로 대응하려면 온실가스 발생량에 대한 정확한 자료 확보가 반드시 필요하며 온실가스 배출량의 정확한 평가는 모든 기후변화 대응 연구의 기본이다. 따라서 유엔 기후변화협약 당사국은 IPCC의 기후변화협약 제4조와 제12조에 따라 온실가스 배출량을 국제적으로 인정된 방법과 당사국총회에서 인정된 비교 가능한 방법에 기초하여 산정하여야 하며 산정된 결과를 CRF (Common Reporting Format)나 국가보고서 (National Inventory Report) 형태로 당사국 총회에 제출하여야 한다. 세계 여러 나라의 농업환경이나 작물의 재배방법은 매우 다양하며 결과적으로 온실가스 배출 특성도 큰 차이를 보여 온실가스 배출량 계산시 단위면적이나 단위조건에 동일한 배출량 계수를 적용할 수 없다. 따라서 IPCC는 각 국가의 자연환경 등을 고려한 국가고유 배출계수를 개발하여 온실가스 배출량 평가에 사용할 것을 권장하고 있으며 배출계수 개발을 위해 적용한 방법이나 배출계수에 대해서는 IPCC 전문가 그룹의 검증을 거치도록 하고 있다. 여러 가지 온실가스 중 아산화질소는 대부분이 농업에 사용된 질소비료의 질산화나 탈질과정을 통해서 배출되며, 질소가 시용된 농경지에서 바로 배출되는 직접배출과 다른 지역으로 이동하여 배출되는 간접배출로 구분된다 (Dowdell et al., 1979; Hiscock et al., 2003).아산화질소의 수계에 의한 간접배출은 농경지에 사용된 질소가 물을 따라 외부로 유출되어 배출되는 것으로 IPCC의 가이드라인에 의해 식 (1)과 같이 농경지에 사용된 전체

This study was conducted to compare of greenhouse gas emissions between 1996 and 2006 IPCC (Intergovernmental Panel on Climate Change) guidelines change. Greenhouse gas emissions were calculated separately by rice cultivation, agricultural soils and field burning of agricultural residues from 2000 to 2008 according to 1996 and 2006 IPCC guidelines. To calculate greenhouse gas emissions, emission factor and activity data were used IPCC default value and the food, agricultural, forestry and fisheries statistical yearbook of MIFAFF (Ministry for Food, Agriculture, Forestry, and Fisheries). The greenhouse emissions by 1996 IPCC guidelines were highest in rice cultivation as 4,008 -eq Gg of 2000 and 3,558 -eq Gg of 2008. The emissions by N-fixing crops, crop residues returned soils and field burning did not much affect the total emissions. emissions by urea and lime were calculated by adding in 2006 IPCC guidelines and its emissions were 157 and 82 -eq Gg in 2008 respectively. The emissions by N-fixing crops, crop residues returned to soils and field burning, in common with 1996 IPCC guidelines, did not have a significant impact on total emissions. The total emissions in agronomic sector was decreased continuously from 2000 to 2008 and annual emissions by 2006 IPCC guidelines were approximately 26-29% less than the 1996 IPCC guidelines.