• Article

    Validation of Stable Isotope Analysis in R (SIAR) Model for Source Appointment of Agricultural Water Pollution
    Hyun-Jin Park, Sang-Sun Lim, and Woo-Jung Choi
    The ‘Stable Isotope Analysis in R (SIAR)’ is useful in estimating the contribution of non-point pollution source to water pollution in intensive ... + READ MORE
    The ‘Stable Isotope Analysis in R (SIAR)’ is useful in estimating the contribution of non-point pollution source to water pollution in intensive land-use areas with divergent pollution sources. However, the accuracy of the SIAR model has not been validated. In this study, the accuracy of the SIAR model was validated using simulation data set, and the applicability of the SIAR model was tested using literature data set. For source appointment of water pollution using SIAR, chemical variables including stable carbon (δ13C) and nitrogen (δ15N) isotope ratios as well as stoichiometry of C, N, and phosphorus (P) such as C/N, N/P, and C/P were used as end-members, which are the representative values of water chemistry variables for each potential source. In the simulation study, it was found that at least (n-1) end-members are required for accurate (r2>0.90 for regression between given and estimated contribution of pollution sources) estimation of pollution source when the number of sources is n. However, it was also suggested that using correct tracer that represents the source characteristics is critical for the accurate estimation of pollution source. Therefore, it is recommended to use end-members > (n-1) for more accurate estimation of pollution sources. In the study of SIAR model application to a case study with 5 sources and 2 or 3 end-members (C/N, C/P, and δ13C for total C; C/N, N/P, and δ15N for total N; and C/P and N/P for total N), it was possible to appoint source contribution for total C, N, and P in water. However, the accuracy of the estimation is expected to be low due to less number of end-member used in SIAR than the recommendation (i.e., n-1). Therefore, it is highly necessary to develop end-members to represent the sources of total C, N, and P for improvement of the accuracy of source appointment using SIAR model. Diagrams of model output of SIAR: (a) bi-plot, (b) histogram, (c) matrix plot, and (d) box plot. - COLLAPSE
    November 2020
  • Article

    Effect of Reducing Ammonia Volatilization from the Arable Soil with Iron Sulfate
    Seong Min Park, Sung Un Kim, and Chang Oh Hong
    Ammonia (NH3) reacts with nitric acid or sulfuric acid in the atmosphere and contributes to the formation of fine particulate matter ... + READ MORE
    Ammonia (NH3) reacts with nitric acid or sulfuric acid in the atmosphere and contributes to the formation of fine particulate matter. It is mainly produced by application of nitrogen fertilizer and livestock manure to the arable soil. Volatilization of NH3 could decrease with application of acidic amendments such as iron sulfate (FeSO4) through decreasing soil pH. This study was conducted to determine an optimum application rate of FeSO4 to reduce NH3 volatilization and maintain crop productivity in arable soil. Iron sulfate was applied at the rates of 0, 50, 100, and 200 kg Fe ha-1. Cabbage (Brassica rapa L.) was planted on April 8th 2020 and harvested on June 10th 2020. The NH3 gas was collected using static chamber (300 mm in length and 120 mm diameter) method. Cumulative NH3-N volatilization decreased significantly with increasing application rate of FeSO4. It decreased by ca. 21% at 200 kg Fe ha-1 of FeSO4. Soil pH decreased significantly with increasing application rate of FeSO4. A decrease in cumulative NH3-N volatilization with FeSO4 was mainly attributed to decrease in soil pH. Cabbage yield did not decreased with increasing application rate of FeSO4. The maximum cabbage yield was 7.10 Mg ha-1 and cumulative NH3-N volatilization decreased by 10.2% from 28.4 kg ha-1 63 days-1 to 25.8 kg ha-1 63 days-1 with 110 kg Fe ha-1 of FeSO4 application. Cumulative NH3-N volatilization from soils amended with different rates of FeSO4 - COLLAPSE
    November 2020
  • Article

    Changes in Soil Salinity and Upland Crop Productivity in Reclaimed Land as Affected by Groundwater Table
    Su Hwan Lee, Yang Yeol Oh, Jin Hee Ryu, Hak Sung Lee, Bang Hoon Kang, Hee Kyeong Ock, and Kang Ho Jung
    Soil salinization driven by groundwater distribution in the reclaimed land is one of the major limiting factors for crop cultivation and soil ... + READ MORE
    Soil salinization driven by groundwater distribution in the reclaimed land is one of the major limiting factors for crop cultivation and soil management. In this study, the effects of two different water table depth (G1 site with intermediate and deep vs. G2 site with shallow depth) of groundwater (on soil salinity, water and crop productivity were investigated. The rainfall event greatly impacted the groundwater recharging rate and salt leaching. The falling groundwatr table depth from 30 to 80 cm together with higher evaporation at G2 site caused soil salinization in the rhizosphere, whereas increases in soil salinity at G1 site was negligible. Overall, soil water content at G2 site was higher than that at G1 site. The positive correlation of soil salinity with soil water content (r2 = 0.69) and negative with groundwater table (r2 = 0.89) indicated hydraulic connection between groundwater table and soil surface. The deeply falling groudwater table with negative water balance (Evaporation > Rainfall) induced drought-combined salt stress to crop. Soybean was much more susceptible to soil salinty stress and excess-moisture injury than maize, suggesting that the crop selection and practices to reduce crop vulnerability to abiotic stresses(salt and water) should be considered for sustainable and stable agriculture in reclaimed land. Our results highlight that groundwater table depth would play a crucial role in founding cropland suitability and the optimum groundwater table to avoid salinization and excessve wetting might be 1.5 - 2.0 m. Distribution of Soil EC in the soil profiles of two fields with different groundwater table variations after maize and soybean harvest in 2015 and 2016 at Saemangeum (G1: Site with intermediate and deep groundwater table, G2: Site with shallow groundwater table). - COLLAPSE
    November 2020
  • Article

    Effects of Different Nitrogen Fertilizer and Biochar Applications on CO2 and N2O Emissions from Upland Soil in the Closed Chamber
    Sun-Il Lee, Gun-Yeob Kim, Hyo-Suk Gwon, Jong-Sik Lee, Eun-Jung Choi, and Joung-Du Shin
    Carbon dioxide (CO2) and nitrous oxide (N2O) emissions from soil are expected to vary with type of nitrogen fertilizer ... + READ MORE
    Carbon dioxide (CO2) and nitrous oxide (N2O) emissions from soil are expected to vary with type of nitrogen fertilizer used. Biochar has recently been proposed as a potential solution to mitigate climate change by reducing greenhouse gas emissions from soils. Incubation experiment was conducted to investigate the effect of different types of biochar on CO2 and N2O emissions when different nitrogen fertilizers used in upland soil. The treatment consisted of different nitrogen fertilizers such as urea, ammonium sulfate and oil cake, and three types of biochars from pear branch, rice hull and soybean stalk. Soil moisture content was adjusted to 70% of the water holding capacity at 25°C. CO2 and N2O gases were collected and analyzed. The cumulative CO2 emissions were 119.4 g m-2 for urea, 107.1 g m-2 for ammonium sulfate, 381.5 g m-2 for oil cake, 137.1 - 154.8 g m-2 for urea + biochars, 114.4 - 161.5 g m-2 for ammonium sulfate + biochars, and 396.9 - 416.4 g m-2 for oil cake + biochars. The cumulative N2O emissions were 216.6 mg m-2 for urea, 44.2 mg m-2 for ammonium sulfate, 347.7 mg m-2 for oil cake and 123.7 - 208.3 mg m-2 for urea + biochars, 39.1 - 114.9 mg m-2 for ammonium sulfate + biochars and 108.9 - 184.2 mg m-2 for oil cake + biochars. No significant differences were observed in N2O emissions among biochar types, except for the mixture of soybean stalk biochar and ammonium sulfate. However, N2O emission was related to both biochar input amount and nitrogen fertilizer types. In particular, N2O reduction effect was great in the addition of biochar when oil cake is mixed into soil. It is considered that further long term field study is needed to apply the biochar use in farming practices. Cumulative total CO2 and N2O emissions from different biochar-amended soil with application of oil cake in the closed chamber. (Nitrogen source : Oil cake) - COLLAPSE
    November 2020
  • Article

    Evaluating Pollution Indexes using Heavy Metal Concentrations in Agricultural Soils around Industrial Complexes in the Jeon-Nam Regions of Korea
    Sorakon Suwanmanon and Ki In Kim
    The main purpose of this study was to investigate soil contamination using heavy metal analysis in agricultural fields around industrial complexes in ... + READ MORE
    The main purpose of this study was to investigate soil contamination using heavy metal analysis in agricultural fields around industrial complexes in the Jeon-Nam regions in Korea. Ten counties in Jeon-Nam province for soil samples near industrial complexes were Gwangyang, Muan, Yeongam, Hampyeong, Haenam, Naju, Jangheung, Boseong, Yeosu, and Damyang. At agricultural field sites soil samples were collected in the spring of 2018 at two soil depths (0-15 cm and 15-30) within a 500- and 1000-meter radius next to industrial complexes before planting. All soil samples were analyzed for the 8 heavy metals including arsenic (As), cadmium (Cd), chromium (Cr), cupper (Cu), nickel (Ni), lead (Pb), mercury (Hg) and zinc (Zn). The results showed that the heavy metal concentrations were below the levels of Soil Contamination Warning Standard (SCWS) for agricultural lands (Region 1) which is regulated by Soil Environment Conservation Law (SECL) established by Ministry of Environment (MOE), Korea. Other heavy metal indexes such as soil pollution index (SPI), pollution index (PI), and pollution load index (PLI) were evaluated to determine contamination of soils due to heavy metals. If SPI is less than 1.0, then soil heavy metal concentration is within the levels of soil contamination warning standard. In this study, SPI is less than 1.0 that means soil is not contaminated. Second, PI for the studied soils is less than 1.0, which classified into “Classification index 1” which means uncontaminated soils. Lastly, PLI for studied soils is between 0.10 and 0.24, classified into “Classification index 2” which is unpolluted soil. For interpreting the PI, the heavy metal concentration and background concentration should be used very carefully if the heavy metal concentration in the soil is lower than the background concentration. In this case, PI value of Hg can mislead interpretation if the soil heavy metal concentration is less than the background concentration. For example, Hg concentration for the background concentration is 0.025 mg kg-1 and Hg concentration for studied soils ranged from 0.000 to 0.004 mg kg-1. Further research is needed to continue to monitor soil heavy metal distribution near industrial complexes in Jeon-Nam province of Korea. Descriptive statistics of heavy metals concentration in agricultural soils near the industrial complexes in Jeon-Nam Province in Korea. - COLLAPSE
    November 2020
  • Article

    Prediction Model for Hourly Soil Temperature by Soil Depth to Irrigated Sandy Loam Soil in Greenhouse
    Seung-Oh Hur, Jung-Hun Ok, Seon-Ah Hwang, Hee-Rae Cho, Yong-Seon Zhang, and Hyup-Sung Lee
    The soil temperature in the greenhouse reacts differently with changes of soil temperature affected by the outside temperature because it is heated ... + READ MORE
    The soil temperature in the greenhouse reacts differently with changes of soil temperature affected by the outside temperature because it is heated in winter or cooled in summer to maintain the temperature. This study was conducted to analyze the changes of soil temperature by soil depth in the greenhouse and to create a model to predict soil temperature. As a result of measuring and analyzing from December 13, 2019, to May 28, 2020, the average soil temperature was lowest in January, and then continuously increased from February to May. The amplitude, which is the difference between the highest and lowest soil temperature, tends to decrease by the depth increases from 0-10cm to 50-60cm. This tendency to decrease could be expressed as a function of exponential decrease by soil depth. As a result of comparison with the Fourier series and sinusoidal function models, the sinusoidal model shows statistically the same value with the Fourier series model and is more useful. However, since the sinusoidal function model is less accurate in predicting temperature change with a slope, a corrected model that can reflect the temperature change slope was required. As a result of the analysis, the following model could be used. f(x)=A0+Ansin(2πTx+ϕ)±C・x±D・x2 where, f(x) is soil temperature, A0 is initial temperature, An is amplitude, T is period, ϕ is phase, x is time. This is a model in which a sine wave function representing periodicity is combined with a quadratic function that can take into account the slope of temperature change. If the quadratic function coefficient is positive, it can simulate the tendency to increase and decrease when the coefficient is negative. This model generally well-simulate soil temperature by soil depth during the measured period. The significance of this study is to analyze and predict the soil temperature in the greenhouse. Besides, the advantage of being able to take into account the gradient of temperature change can be used to predict soil temperature under outdoor conditions. Comparison of measured & predicted soil temperature (Soil depth : 0 - 10 cm). Prediction model for hourly soil temperature f(x)=A0+Ansin(2πTx+ϕ)±C・x±D・x2 - COLLAPSE
    November 2020
  • Article

    Characterizations of Growth, Yield and Water Use Efficiency of Adzuki Bean as Affected by Drought Stress
    Hyen Chung Chun, Sanghun Lee, Dong Hyeok Gong, Young Dae Choi, and Ki Yuol Jung
    Accurate and optimal water supply to crop is critical in growing stalks and producing maximum yields. Adzuki bean is one of the ... + READ MORE
    Accurate and optimal water supply to crop is critical in growing stalks and producing maximum yields. Adzuki bean is one of the representative legume crops and known as a vulnerable crop to water stress. This study investigated drought effect on adzuki bean at various growth stages and water use efficiency (WUE) with different soil moisture contents in order to evaluate response of adzuki bean to drought. The experiment was performed at National Institute of Crop Science in Miryang. Adzuki beans were planted in a Wagner pot filled with 50% of silt loam soil and 50% of bed soil. Drought treatment was applied at six growth stages: V1, V3, V5, R1, R3, R5. Another pot experiment was performed in a stainless steel pot with an automated irrigation system in order to maintain targeted soil moisture content (40, 60 and 80% of field capacity). Growth and yield characteristics of adzuki bean were measured from all pots. Crop susceptibility (CS) was calculated from the Wagner pots to quantify drought effect at each growth stage and WUE was measured from the stainless pots to determine the least water requirement to prevent drought damage. Drought effect was the greatest in growth reduction at V1 and yield reduction at R3. CS value was the smallest value at V3 and the greatest at R3. Growth, yield and WUE data of adzuki bean were not different between soil moisture 60% of field capacity and 80%, while ones from 40% soil moisture content were smaller than others. Adzuki bean exhibited great vulnerability to drought stress at reproductive stage and it required at least soil moisture 60% of field capacity to prevent drought damage. These results will be useful to water management of adzuki bean and prevent drought damage in adzuki bean cultivation. Results of daily water used from adzuki bean cultivated with different soil moisture content (40, 60, 80% of filed capacity). DAP represents days after planting. - COLLAPSE
    November 2020
  • Article

    Regression Model to Predict Nitrogen Mineralization Using Soil Parameters for Pepper Upland
    Yejin Lee, Seulbi Lee, and Jwakyung Sung
    One of the most important practices for nitrogen (N) management in arable lands is to minimize N loss using soil-customized N supply ... + READ MORE
    One of the most important practices for nitrogen (N) management in arable lands is to minimize N loss using soil-customized N supply. Despite that N mineralization of soils is an useful parameter to manage N fertilization, it requires a lot of analysis. To predict N mineralization rate of upland soils, we performed regression analysis between N mineralization parameters (Mineralized N, N0, k) and soil properties. Experimental soils were randomly sampled from 40 pepper cultivation fields before fertilization. The rate of soil N mineralization was analyzed through incubation for 16 weeks at 27°C. N mineralization parameters of soils were estimated from first-order kinetic model, and a stepwise regression was conducted to predict the mineralized N, N0 and k using soil properties. Mineralized N was linearly correlated with EC (R2=0.745) which meant a good indicator to predict N mineralization rate. N0 as potentially mineralizable N was positively correlated with soil organic matter (SOM) and total N, and those represented a linear relationship (y=0.0682x, R2=0.729). SOM, sand, clay and C/N ratio were selected as parameters for prediction of N0 (R2=0.448). In addition, a regression equation for estimation of k was composed of EC, CEC, sand and clay (R2=0.508). In conclusion, we suggest that N mineralization rate by combination with soil properties could be determined with a regression equation. However, model equation represented in this study should be validated and improved through field experiments with different levels of N application and different types of soil property. Stepwise multiple regression equations for estimating nitrogen mineralization factors in relation to soil properties. - COLLAPSE
    November 2020
  • Article

    The Effects of Ethephon Application on Suppressing Methane Emission and Stimulating Rice Productivity in a Rice Paddy Soil: A Pot Experiment
    Seongwoo Choi, Juhee Lee, Yeomyeong Lee, Pil Joo Kim, Ju-Sik Cho, Yong Hwa Cheong, Yo-Sup Rim, and Sang Yoon Kim
    Ethephon is one of the chemical stimulator of crop growth that is also considered as a structural analogue of coenzyme M (CoM ... + READ MORE
    Ethephon is one of the chemical stimulator of crop growth that is also considered as a structural analogue of coenzyme M (CoM), having a promising potential for methanogenic inhibitor. However, the effect of ethephon application on greenhouse gas (GHG) emissions under rice cultivation has not been studied yet. In this pot experiment, different levels of ethephon (0, 2.5, 5 and 10 mg L-1) were applied at the presence or absence of manure compost as an organic amendment to study its effect on GHGs emissions in particular CH4 and rice productivity during the cultivation. Application of ethephon effectively suppressed CH4 emissions in particular the initial periods (ca. 3 weeks) right after the application as compared with control soil during rice cultivation, but did not significantly affect N2O emissions. In addition, the maximum CH4 reduction (82% reduction over control) was found at 10 mg L-1 ethephon application right after its addition for 3 weeks during rice cultivation. Rice productivity and yield properties were mainly affected by ethephon application, enhancing ripened grains and number of grains per panicle. Soil properties were not influenced by ethephon application except for available phosphate, which is probably due to enhanced root growth in rhizosphere soils. Conclusively, ethephon could be a new and pioneering amendment for reducing CH4 emission in particular at the initial 3 weeks after the application without increasing other GHG emissions and enhancing rice productivity in paddy soils. Ethephon application showed a potential to suppress greenhouse gas emissions in particular methane and to enhance rice productivity by ca. 5 mg L-1. - COLLAPSE
    November 2020
  • Article

    Growth Characteristics and Seed Productivity of Italian Ryegrass (Lolium multiflorum L.) Cultivars under Different Salinity in Saemangeum Reclaimed Tideland
    Hyeonsoo Jang, Hui-su Bae, Seung-hyun Ahn, Jong-tag Youn, Dea-wook Kim, and Wook-han Kim
    Although the forage production area of ​​Italian ryegrass is expanding in Korea, most of the seeds are imported from abroad. This study ... + READ MORE
    Although the forage production area of ​​Italian ryegrass is expanding in Korea, most of the seeds are imported from abroad. This study was conducted to examine seed productivity of domestic varieties of Italian ryegrass under different soil salinity in reclaimed tideland. Compared to 0.1% of soil salinity, the emergence rate at 0.2 - 0.3% salinity decreased by 7%. The number of ear and grain weight also decreased at the 0.2 - 0.3% of salinity, eventually leading to 23% decreases in seed yield compared to the 0.1% salinity. There was no significant difference in yield components among cultivars, but Greenfarm showed slightly higher yield components than other cultivars. Therefore, when domestic cultivars are harvested in reclaimed land, it is expected to increase the self-sufficiency of domestic seeds and to replace imports of foreign seeds. Growth characteristics and yield components of Italian ryegrass under different soil of Saemangeum reclaimed tideland. - COLLAPSE
    November 2020
  • Article

    Investigation of Soil Cr and Ni Contamination in Different Land Uses and Tracing the Source of Contamination
    Minju Jo, Mina Lee, and Kwon-Rae Kim
    Chromium (Cr) and nickel (Ni) are commonly used heavy metals in alloy manufacture. In Korea, most research on heavy metal(loid)s ... + READ MORE
    Chromium (Cr) and nickel (Ni) are commonly used heavy metals in alloy manufacture. In Korea, most research on heavy metal(loid)s focused on As, Cd, Cu, Pb, and Zn, and little attention has been paid to Cr and Ni. However, recent studies showed that they were gradually increasing in the soils, especially when the soils were influenced by human activities. Thus, this study aims to investigate soil Cr and Ni concentrations in different land uses and trace the source of Cr and Ni contamination. Cr and Ni concentrations in different use of soil were obtained from literature and soil analysis. Also, to identify the impact of dust deposition on the soil Cr and Ni, Cr and Ni levels in air dust from various areas were studied by literature review and air dust analysis. Soil Cr and Ni concentrations were higher near roadsides and industrial complexes, and their concentrations had a strong linear correlation. This indicates that Cr and Ni could have a common source of contamination such as vehicles. Similarly, Cr and Ni concentrations in air dust were also higher near roadsides, urban areas, and industrial areas. Therefore, Cr and Ni loads on soils are highly related to traffic and industrial activities. Averaged Cr and Ni concentrations in different soil uses compared to Korean natural background levels.. - COLLAPSE
    November 2020
  • Article

    Effect of Controlled-Release Coated Fertilizer on Yield and Nitrogen Use Efficiency in a Red Pepper Cultivated Field
    Jong-Hyeong Lee, Byoung-Rourl Choi, Gwang-Grae Cho, Eun-Kyu Jang, Young-Rok Kim, Jung-Hyeun Ji, Hong-Sik Na, Sang-Eun Lee, and Hyun-Hwoi Ku
    Improving the nitrogen use efficiency (NUE) of crops is a technology that improves crop productivity and prevent environmental pollution simultaneously. A way ... + READ MORE
    Improving the nitrogen use efficiency (NUE) of crops is a technology that improves crop productivity and prevent environmental pollution simultaneously. A way to improve NUE is to develop and use a controlled release fertilizer. We developed a controlled release fertilizer in terms of controlled-release coated fertilizer for rhizosphere application (CRFR) which is a mineral fertilizer applying just under the plant root zone. In order to test effect of the developed CRFR on crop yield and NUE, field experiments were conducted with six levels of N (N 0, N 190, CRFR-N 16, CRFR-N 22, CRFR-N 27, and CRFR-N 33 kg ha-1) at the experimental station of Gyeonggi-do Agricultural Research & Extension Services (GARES) for two years (2017 to 2018). The fruit yield and NUE of red pepper were obtained using agronomic measurements. To determine optimum N rate of CRFR we applied linear-plateau model. Results showed that the yield was not significantly different between the two levels of CRFRs (N 22 and 27) and N 190 in 2017. Similarly, the yield was not different between the three levels of CRFRs (N 22 and 27) and N 190 in 2018 although almost six times as much N rate was applied in the N 190. Meanwhile, NUEs in the CRFRs were ranged from 69.8 to 88.5% which were much higher than the N 190 treatment (14.8%). Since CRFRs showed no different yields as compared to N 190, we analyzed the optimum rate of CRFR using the linear plateau model and CRFR applied at 23.1 kg N ha-1 was optimal for the yield. Our results suggest that CRFR was able to significantly increase crop productivity while reduce environmental pollution because of remarkably high NUE. Since CRFRs showed no different yields as compared to N 190 (recommended N dose from RDA), we analyzed the optimum rate of CRFR using the linear plateau model, and CRFR applied at 23.1 kg N ha-1 was optimal for the yield. - COLLAPSE
    November 2020
  • Article

    Characteristics of Ammonia Gas Emission from Soybean Cultivation Soil with Biochar, Fly ash and Microorganisms
    Su-Lim Lee, Jae-Hoon Lee, Jong-Hwan Park, Se-Wook Hwang, and Dong-Cheol Seo
    As ammonia gas caused by nitrogen supply source such as urea in soil is identified as a source of particulate matter, an ... + READ MORE
    As ammonia gas caused by nitrogen supply source such as urea in soil is identified as a source of particulate matter, an eco-friendly method to reduce ammonia gas emission while using chemical fertilizers to provide the nutrients required by crops is needed. Therefore, this study evaluated the effects of microorganisms, biochar and fly ash, known as soil conditioners, on the amount of ammonia gas generated in urea-treated soil. The ammonia gas emissions from the soils treated with urea rapidly increased in 2 days, and then declined sharply between days 3 and 15. On the other hand, as a result of adding biochar to the soil treated with urea, the amount of ammonia gas that occurred rapidly in 2 days was reduced, which was dependent on the added amount of biochar. Both Alcaligenes faecalis subsp. and Brevibacillus sp. was effective in reducing ammonia gas generated from urea treated soil. However, the amount of ammonia gas generated from urea-treated soil under different fly ash dosage increased gradually as the amount of fly ash increased, which was considered to be closely related to the pH variation of soil. Above all, biochar and microorganisms have a positive effect on reducing ammonia gas generated from urea-treated soil, while fly ash has a negative effect. iochar and microorganisms have a positive effect on reducing ammonia gas generated from urea-treated soil, while fly ash has a negative effect. [Control (soil 50 g), S+N (soil 50 g+urea 1 g), S+N+1.0B (soil 50 g+urea 1 g+biochar 1.0 g), S+N+1.0FA(soil 50 g+urea 1 g+fly ash 1.0 g), S+N+BB (soil 50 g+urea 1 g+ Brevibacillus sp. 5 mL), S+N+AF (soil 50 g+urea 1 g+ Alcaligenes faecalis subsp. Faecalis 5 mL)] - COLLAPSE
    November 2020
  • Article

    Residual Effects of Organic Materials on N Supply to Chinese Cabbage and Soil Under Continuous Cultivation
    Cho-Rong Lee, Yura Oh, Jung A Jung, Sang-Min Lee, and Nan-Hee An
    Nitrogen (N) supply from organic materials (OM) takes more time than chemical fertilizer (CF), because mineralization of organic N requires microbial conversion ... + READ MORE
    Nitrogen (N) supply from organic materials (OM) takes more time than chemical fertilizer (CF), because mineralization of organic N requires microbial conversion. Most organic N applied to soil remains into SOM. It might have a greater residual effect than CF on soil fertility and crop nutrient uptake and influence on N fate. Residual organic N might have influence on soil fertility and nutrient uptake of crop by depending on N cycling in soil. This study investigated the residual effect of 15N-labeled organic materials on Chinese cabbage N uptake and soil N. 15N-labeled organic materials at rate of 456 kg N/ha applied with green manure (GM), livestock compost (LC), GM+LC, oil cake (OC), and CF into wagner pot (1/2000a) for Chinese cabbage cultivation. During continuous crop cultivation (Sep. 2018 to Mar, 2020), 15N-labeled Chinese cabbage and soil was analyzed by using stable isotope elemental analyzer. Organic materials and chemical fertilizer were higher N uptake in Chinese cabbage than in the control at first cropping season. However, N uptake of Chinese cabbage under continuous cultivation was significantly increased 35-72% at organic material treatments compared to the control. Also, 15N-labeled soil was significantly high at the treatments applied with GM, LC, and GM+LC, but was not at OC and CF treatment. In conclusion, organic materials (especially GM, LC, and GM+LC) had a greater N residual effect on Chinese cabbage and soil than chemical fertilizer. Chinese cabbages N uptake and soil N content were affected by residual effect of treatments after application. Organic materials had a greater residual effect on Chinese cabbage and soil than chemical fertilizer (n=4). - COLLAPSE
    November 2020
  • Article

    Status and Changes in Chemical Properties of Upland Soil in Gangwon Province between 2001 and 2017
    Byeong Sung Yoon, Seung Chul Choi, Soo Jeoung Lim, Su Jeong Heo, and Youngho Seo
    In order to obtain useful information for environment-friendly management of upland soils, the chemical characteristics of 170 upland fields in Gangwon province ... + READ MORE
    In order to obtain useful information for environment-friendly management of upland soils, the chemical characteristics of 170 upland fields in Gangwon province have been monitored every 4 years since 2001. In 2017, the pH, electrical conductivity (EC), organic matter (OM), and available phosphate (Avail. P2O5) of the soil samples were 6.4, 0.89 dS m-1, 32 g kg-1, and 742 mg kg-1, respectively. The values of exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 1.18, 7.6, and 2.0 cmolc kg-1, respectively. In terms of the long-term change, the contents of EC, OM, and Exch. cations in upland soils showed increasing tendency. However, significant changes in the contents of pH and Avail. P2O5 were not observed since 2013. The ratio of optimal range of pH and OM in upland fields reduced from 55% in 2001 to 36% in 2017 and from 33% to 27%, respectively. The ratio of excessive range of Exch. cations have increased. Therefore, it is necessary to apply the lime and fertilizers based on the soil test in order to properly manage the soil fertility of the upland soils. Meanwhile, average contents of Cd, Cu, Ni, Pb, Zn, and As were 0.23, 21.0, 13.5, 11.0, 82.6, and 4.8 mg kg-1, respectively. The results from the study imply that environment-friendly soil managements including the cultivation of green manure crop and application of organic composts are necessary to improve the soil chemical properties of upland fields. Excess, deficient and optimal range of chemical properties of upland soils in Gangwon Province (n = 170). - COLLAPSE
    November 2020
  • Article

    Identification of Automobile-Derived Heavy Metal(loid)s Possibly Loaded to Soils Through Air Dust Deposit
    Mina Lee, Nam-Kyung Kim, and Kwon-Rae Kim
    Recently, soil heavy metal(loid) contamination has become a big issue. Literature showed that roadside soils had a higher level of heavy ... + READ MORE
    Recently, soil heavy metal(loid) contamination has become a big issue. Literature showed that roadside soils had a higher level of heavy metal(loid)s because of contaminated air dust. This study aims to investigate which heavy metal(loid)s are related to automobile and to understand the degree of automobile impact on soil contamination. Samples were collected from each part of the automobile, floors, and windows of four auto repair shops. Soils near the auto repair shops were also collected and analyzed. The levels of Zn, Cu, and Cr were higher in the metallic alloy-related parts, such as wheels, brake pads, and internal combustion engines. Paintings and tires were mainly related to Zn and Cu discharge. Cd, Ni, and Pb were detected from the samples although they were not primary. The air dust from the floors, windows, and the soils near auto repair shops also showed high levels of these heavy metals. This supports that the elements derived from automobile discharge to the air and become a source of roadside soil contamination. Cr and Ni were reported to have a high correlation in contaminated soils, which would because they were the materials of automobile alloy, so discharged together. Heavy metal(loid) contents in wheels, brake pads, internal combustion engines, paintings, and tires. - COLLAPSE
    November 2020
  • Article

    Soil Water Profiles, and Growth and Yield of Waxy Corn as Affected by Different Tillage in Upland Converted from Paddy Field
    Woo-Jung Choi and Han-Yong Kim
    In Korea, rice consumption per capita has steadily been reducing, and hence the harvested area of paddy rice decreased by 18% from ... + READ MORE
    In Korea, rice consumption per capita has steadily been reducing, and hence the harvested area of paddy rice decreased by 18% from 892,074 ha in 2010 to 729,814 ha in 2019 during last decade, leading to the potential to stimulate upland crop production in converted-upland from paddy field. Here, we examined how tillage practice, rotary (RT) in 12cm depth vs. rotary combined with deep tillage (RTDT) in 25cm depth, would affect vertical profiles (0 to 40 cm at 10 cm interval) of soil water and, growth and yield parameters of waxy corn (Zeay Mays L., ceratina, cv. Ilmichal) grown as sequential cropping of barely in upland field converted from paddy field. With rainfall and sprinkler irrigation, vertical profiles of soil water were varied greatly (20 cm > 40 cm > 30 cm > 10 cm) over whole season in RTDT plot, but not in RT plot. Tillage treatments did not alter plant height, SPAD value, ear setting height, ear number, ear length and ear width of waxy corn. However, the RTDT significantly increased stem diameter by 7.7% (27.1 mm vs. 29.1 mm), above-ground biomass by 28.3% (1,170 g m-2 vs. 1,501 g m-2) and ear fresh yield by 22.4% (1,278 g m-2 vs. 1,564 g m-2). The results suggest that tillage management is likely to be an option to secure upland crop production in drained-paddy which has a potential of crop loss by excessive moisture injury. However, the results that we observed were derived from the first-year upland field converted from paddy field, highlighting a necessity of further studies in second- and third-year upland field converted from paddy field to clarify the long-term effect of tillage practices on waxy corn production. Vertical profiles of soil water in upland field converted from paddy field were varied greatly in rotary combined with deep tillage plot (B), but not in rotary only plot (A). - COLLAPSE
    November 2020
  • Article

    Estimation of Greenhouse Gas Emission in Rice Paddy Soil Under Slow Released N Fertilizer Application: Annual Investigation
    Hyo-Suk Gwon, Gun-Yeob Kim, Sun-Il Lee, Jong-Sik Lee, and Eun-Jung Choi
    Intermittent drainage can reduce methane (CH4) emission from rice paddy soils, but nitrous oxide (N2O) emission can increase. We ... + READ MORE
    Intermittent drainage can reduce methane (CH4) emission from rice paddy soils, but nitrous oxide (N2O) emission can increase. We believe that the slow released N fertilizer can mitigate N2O emissions by reducing N lost to the environment. In this study, we tried to assess the influence of slow N fertilizer on effective greenhouse gas (GHG) reduction. We installed three different treatments, urea (U) treatment, controlled release fertilizer (CRF) treatment, and hairy vetch with urea (HV) treatment. The emission rates of CH4 and N2O were monitored using the closed chamber method during cropping and fallow season. The grain yield was investigated to calculate yield scaled greenhouse gas intensity (GHGI). Compared with U treatment, CH4 emission was reduced in CRF but increased in HV treatment. In contrast, N2O emission was increased in CRF but reduced in HV treatment. Grain yield was increased in CRF and HV treatment than U treatment. The GHGI was the lowest in CRF treatment by high grain yield and low GHG emission. In contrast, GHGI was the highest in HV treatment due to increased CH4 emission. In conclusion, controlled release fertilizer can effectively reduce GHG emission. However, CRF application increased N2O emissions during the fallow season, and further investigation is needed to determine whether this is due to the effect of fertilizer residues. In addition, due to field experiments that are easy to influenced by the environmental condition, it seems necessary to verify the research results through additional investigations over many years. Grain yield, total GWP and GHGI during annual season in rice paddy under difference type of nitrogen fertilizer application. - COLLAPSE
    November 2020
  • Article

    Estimation of Winter Wheat Nitrogen Content, Biomass and Yield using UAV Images in South Korea
    Kyung­Do Lee, Ho-yong An, Suk-young Hong, Chan-Won Park, Kyu-Ho So, Sang-In Shim, Gi-Eun Song, and Sang­Il Na
    Unmanned Aerial Vehicle (UAV)s have a high resolution of around 10 cm, and can acquire images with lower cost when we ... + READ MORE
    Unmanned Aerial Vehicle (UAV)s have a high resolution of around 10 cm, and can acquire images with lower cost when we want. The purpose of this study was to estimate the winter wheat nitrogen content, biomass and grain yield using UAV image. We collected the time series UAV aerial images at the upland and the data were compared with the wheat nitrogen contents, biomass and yield in the experimental sites. Correlation coefficient (R) between the vegetation indices (NDVI, GNDVI, RVI, GRVI, NDRE) and wheat nitrogen contents were more than 0.8 from early-April to late-April. Correlation coefficient (R) between the vegetation indices (NDVI, GNDVI, RVI, GRVI, NDRE) and wheat biomass, grain yield, and crude protein were from 0.7 to 0.8 from early-April to late-April. Using these results, we were able to make the distribution map of the wheat nitrogen, biomass and yield. In the future, it will be necessary to study to recommend supplemental fertilization to ensure the wheat yield using UAV images information. Distribution map of biomass, grain weight, and grain crude protein in the winter wheat using UAV imagery. - COLLAPSE
    November 2020
  • Article

    Impacts of Different Nitrogen Fertilization on Greenhouse Gas Emissions and Lettuce Productivity in Upland Soils during Cultivation
    Yeomyeong Lee, Sieun Lee, Juhee Lee, Seongwoo Choi, and Sang Yoon Kim
    Nitrogen (N) fertilization improves crop growth and productivity, but can cause adverse environmental problems in particular nitrous oxide (N2O) emissions ... + READ MORE
    Nitrogen (N) fertilization improves crop growth and productivity, but can cause adverse environmental problems in particular nitrous oxide (N2O) emissions, requiring reasonable fertilization strategy for a better agroecosystem. Our goal was to understand how different N fertilizations influence greenhouse gas (GHG) emissions (CO2, CH4, and N2O) and global warming potential (GWP), soil properties, and productivity from lettuce (Lactuca sativa) cultivated fields [control (No fertilizer), urea ((NH2)2CO), ammonium sulfate ((NH4)2SO4), and compost (10 Mg ha-1)]. Inorganic N fertilizations significantly increased GWP as compared to the control, mainly increasing N2O emissions. However, CH4 and CO2 were not significantly different among all treatments, indicating N2O emissions were main contributors to be influenced by N fertilizations. Ammonium sulfate showed higher GWP than the urea. However, GWP was lowest in the control, but was not significantly different as compared to the compost. Lettuce yield was significantly enhanced by chemical N fertilizations, showing much greater biomass in ammonium sulfate than the urea. Lettuce yield with the compost was less than with chemical fertilizations, but significantly greater than control. GWP per productivity as an indicator for sustainability was lowest in compost treatment among all treatments mainly due to reduced GHG emissions by less mineralization. Conclusively, compost application could be a sustainable way to mitigate GHG emissions, maintaining soil quality and productivity in upland soils. GWP per lettuce yield under different fertilization regimes. - COLLAPSE
    November 2020
  • Article

    Comparison of Pollution Indicies in Assessing the Heavy Metal(loid)s Pollution of Arable Soils Adjacent to Industrial Complex in Gyenggi-do
    Seok Soon Jeong, Hyuck Soo Kim, Sang-Phil Lee, Si Young Choi, Ji Eun Lee, Sung Chul Kim, and Jae E. Yang
    Soils adjacent to the industrial complexes are known to be vulnerable to pollution with the diverse pollutant sources. This research assessed pollution ... + READ MORE
    Soils adjacent to the industrial complexes are known to be vulnerable to pollution with the diverse pollutant sources. This research assessed pollution level in the arable soils located nearby industrial complexes using different pollution indices. Both surface (0 - 15 cm) and subsurface (15 - 30 cm) soil samples were taken from 150 agricultural fields located nearby 15 industrial complexes. Total concentrations of As, Cd, Cu, Ni, Pb, Zn, and Hg in soils were determined after extracting with aqua regia and mostly were lower than the pollution threshold criteria for the agricultural soil designated by the Korean Soil Environment Conservation Act. The calculated PI values for As indicated the unpolluted status but those for all other metals were in the ranges of low to moderately polluted. The Igeo values for Cd and Zn indicated soils were in the unpolluted to moderately polluted ranges, but those for other metals were unpolluted. The Igeo evaluated the pollution level lower than PI due to the geochemical correction factor. The average PINemerow values for surface soil and subsurface soils were 1.26 and 0.73, respectively, indicating a higher pollution in surface soil than subsurface soil. Ranges of PINemerow values showed a wide spectrum of pollution level from clean to heavy pollution, depending on soil sampling sites. All pollution indices indicate that levels of pollution for Cd were higher than other metals. Also four pollution indices exhibited different levels of pollution, even though they are equally based on the total concentrations of heavy metals in soil. This discrepancy might be derived from the fact whether a pollution index considers the geochemical background level, an individual metal or overall metals. The results suggest that a suitable pollution index for the pollution assessment cannot be specified based on the total concentrations of metal in the arable soil. Pollution assessments of the arable soils using (A) single pollution index and (B) geoaccumulation index for each heavy metals, and (C) Nemerow pollution index for the integrated heavy metals in each industrial complex. - COLLAPSE
    November 2020
  • Article

    Assessment of Soil Organic Carbon Fractions and Stocks under Different Farming Practice in a Single Maize Cropping System
    Yun Hae Lee, Myung Sook Kim, Seong Jin Park, Hyun Young Hwang, and Seong Heon Kim
    This study investigated the effect of different fertilization practices on SOC fraction and stock changes during maize cultivation. The experiment consisted of ... + READ MORE
    This study investigated the effect of different fertilization practices on SOC fraction and stock changes during maize cultivation. The experiment consisted of four different fertilizations; no fertilization (control), chemical fertilizer (NPK), NPK+residue (NPKR) and NPK+residue+compost (NPKRC). Dissolved carbon (DOC) and nitrogen (DON), hot-water extractable carbon (HWEC) and nitrogen (HWEN) and humic (HA) and fulvic acid (FA) were determine in the 0-10, 10-20 and 20-30 cm soil layers. The yield of maize under NPKRC(13,202 kg ha-1) was higher than Control (2,699 kg ha-1), NPK (10,240 kg ha-1), NPKR (11,352 kg ha-1). In soil properties, pH, EC, OM, TN, Avail. P2O5 were increased when organic matters applied in soil. The content of soil organic carbon (SOC) was higher in order: NPKRC (4.7 g kg-1) > MPKR(3.4 g kg-1) > NPK (2.9 g kg-1) > control (2.2 g kg-1). The highest SOC stock was observed in NPKRC (21.8 kg C ha-1) due to the high SOC and low bulk density. This pattern is same with HA and FA content. In conclusion, application of organic matter increase maize yield, SOC stock and concentration of labile carbon and stable carbon. Therefore, it is recommendable for suitable soil management strategy to improve soil fertility and increase crop yield in upland soil. HA(humuc acid), FA(fulvic acid), HA/FA and humification rate under different fertilization system. Alphabet indicated significant difference within same soil depth (Duncan’s test, p < 0.05). Contorl, no fertilization; NPK, chemical fertilizer; NPKR, NPK+Residue; NPKRC, NPK+Residue+Compost. - COLLAPSE
    November 2020
  • Short Communication

    Responses of Cabbage Growth to Different Application Ratios of Activated Rice Hull Biochar Mixed Fertilizer
    In-Ho Jung, Hong-Sik Na, Hyun-Jong Cho, Oh-Yeon Kwon, Seung Gil Hong, and JoungDu Shin
    This study was conducted to evaluate how granular slow release fertilizer containing activated rice hull biochar can effect on growth of cabbage ... + READ MORE
    This study was conducted to evaluate how granular slow release fertilizer containing activated rice hull biochar can effect on growth of cabbage and save its fertilizer usage amount. The cabbages (chuwol) were transplanted with randomized block design for 3 replications on September 3rd, 2019, and the treatments consisted of non-fertilizer, control, commercial slow-release fertilizer, conventional practice and activated rice hull biochar mixed with fertilizer (ARHBMF) in 4 different basal fertilizer (21-17-17) levels; 100%, 80%, 60% and 40% before planting. Each treatment received the same amount of additional fertilizer. Regarding this result, it can be reduced at 40% of basal fertilizer application, and the total fertilizer application rate was decreased with 52.8% compared to the control. The highest yield in the 60% ARHBMF was 3.5 kg plant-1 based on one time of basal application and the yield index increased at 20% compared to the control. The application rate of 60% ARHBMF was reduced at 66.7% relative to the application rate of commercial slow-release fertilizer. For the benefit analysis, the cost in the 60% ARHBMF was decreased at 61.8% and 60.8% compared to the control and commercial slow-release fertilization plots, respectively. Benefit analysis of granular types of slow release fertilizer contained activated rice hull biochar during cabbage cultivation - COLLAPSE
    November 2020
  • Short Communication

    Measurement of Soil Surface and Plant Canopy Ammonia Fluxes in Red Pepper Field Using Dynamic Chamber Method
    Hyun-Hwoi Ku
    Ammonia (NH3) gas is the agent of the secondary particulate matter (PM2.5) generated from crop fields amended with organic ... + READ MORE
    Ammonia (NH3) gas is the agent of the secondary particulate matter (PM2.5) generated from crop fields amended with organic and inorganic fertilizer application. The purpose of this study is to provide a more reasonable method of calculating NH3 emissions by comparing amounts of NH3 gas emitted in the soil surface and plant canopy in red pepper cultivated field. And we used two types of dynamic chamber such as soil surface chamber and plant canopy chamber, for comparing seasonal NH3 emissions. Ammonia estimated by soil surface and plant canopy chamber methods were 36.4% and 24.1% of total nitrogen applied to field, respectively. The lower NH3 emission in plant canopy chamber method than that in soil surface chamber method should be attributed to absorption of NH4+ and/or NH3 by plants. Though soil surface chamber method is widely used, it is necessary to develop method for more accurate estimation of NH3 emission from crop fields. Seasonal ammonia emissions measured by plant canopy chamber was 12.3% lower than that measured by soil surface chamber. - COLLAPSE
    November 2020
  • Short Communication

    Simulation of Nitrate Leaching Under Soybean and Chinese Cabbage Cultivation in the Lysimeter Soils Using the APEX Model
    Yejin Lee, Soonkun Choi, and Jae E. Yang
    Nitrate leaching losses from arable land can negatively impact ground water quality. Prediction of nitrate leaching with agricultural system model is helpful ... + READ MORE
    Nitrate leaching losses from arable land can negatively impact ground water quality. Prediction of nitrate leaching with agricultural system model is helpful to manage the crop land for reduction of nitrate leaching. In this study, APEX (Agricultural Policy Environmental eXtender) model was evaluated for simulating the nitrate leaching potential in agricultural land. The model for nitrate leaching prediction was calibrated and validated with the data from the lysimeter in National institute of agricultural science, Rural development administration. The nitrate-N leaching during cropping season of soybean (Jun to October) and Chinese cabbage (September to October) in lysimeter was simulated from 1986 to 2015 with the adjusted model. The measured (x) and simulated (y) total nitrate-N leaching that was accumulated during cropping period in lysimeter was significantly correlated (n = 9, y = 0.9275x, R2 = 0.948). The range of total nitrate-N leaching according to soybean and Chinese cabbage cultivation was 0 - 4 kg ha-1 and 3.8 - 11.6 kg ha-1, respectively. Thus, we confirmed the APEX model reflects differences in nitrate leaching potential under the different types of crop and fertilization. These results suggest that APEX model can be successfully used in estimating nitrate leaching of arable land. Simulated NO3-N leaching by APEX model and precipitation during cropping season of Chinese cabbage(fall) from 1986 to 2015 in the lysimeter. - COLLAPSE
    November 2020
  • Short Communication

    Changes in Soil Chemical Properties of Strawberry, Watermelon, and Tomato-Grown Plastic Film Houses from 2010 to 2019
    Myung Sook Kim, Mi-Jin Chae, Eun-Jin Lee, Tae-Gu Lee, Sung-Hee Kwon, and Ha-il Jung
    This study was performed to evaluate the chemical properties and soil quality of strawberry, watermelon, and tomato-grown soils in the intensive plastic ... + READ MORE
    This study was performed to evaluate the chemical properties and soil quality of strawberry, watermelon, and tomato-grown soils in the intensive plastic film houses. Soil testing data (43,288), uploaded on Korean soil information system (http://soil.rda.go.kr) from 2010 to 2019, were analyzed. The study showed that the average values ​​of pH and organic matter (OM) have been maintained under the optimum ranges, whereas electrical conductivity (EC), available phosphate (Avail. P2O5) and exchangeable (Exch.) cations (K, Ca, and Mg) were increased by 1.2 times in strawberry, and 1.3 times in watermelon and tomato. In addition, the soil chemical quality was the lowest in tomato and followed by watermelon and strawberry. Especially, a chemical quality of tomato-grown soils revealed the most rapid decrease until 2019. In order to improve soil environment for strawberry, watermelon, and tomato cultivation under the plastic film houses, a comprehensive soil management technique such as application of rice straw, chelating agent and microbal material, deep tillage, cultivation of hyperaccumulator for salts should be used to reduce the accumulated nutrients, and considering the results of the soil testing, adequate amount of fertilizer, compost, and soil amendment should be supplied to ensure stable crop productivity. Degree of contribution of soil chemical indicators to strawberry, watermelon, and tomato-grown plastic film houses from 2010 to 2019. - COLLAPSE
    November 2020
  • Short Communication

    Quantification of Drainage Classes of Korean Soils as Morphological Characteristics
    Yeonkyu Sonn, Byunghwan Seo, Woori Go, and Sangho Jeon
    Morphological characteristics provide a variety of important information for soils. Drainage class is also deternmined by the morphological characteristics such as soil ... + READ MORE
    Morphological characteristics provide a variety of important information for soils. Drainage class is also deternmined by the morphological characteristics such as soil color, which indicates the redox state of the soil. Soil color is usually measured with the Munsell color chart, which may not allow perfect conformity of results between surveyers. Quantitative approach, therefore, became more important to determine drainage class. In the quantification of the drainage class, we suggetsted following three factors as key points:ⅰ) earth color (hue, value, chroma), color due to rocks, and color due to redox are important factors, ⅱ) If there is a main color and mottles (color by reduction), the amount and degree of color by redox are important, ⅲ) When there is a groundwater level, the depth and the amount of the mottles (color by oxidation) are important determinants. Furthermore, not only the drainage class but also other characteristics should be quantified to create an Korean own classification system suitable for the characteristics of Korea. Criteria for determining the drainage class. - COLLAPSE
    November 2020
  • Review Article

    Trends of Lysimeter Studies to Investigate Nutrient Leaching Loss
    Yang-Min Kim, Chan-Wook Lee, and Ye-Jin Lee
    Lysimeter is used to monitor water and nutrient transport through soil profiles under minimum disturbance conditions. In this study, we focused on ... + READ MORE
    Lysimeter is used to monitor water and nutrient transport through soil profiles under minimum disturbance conditions. In this study, we focused on the researches about nutrient leaching loss using a lysimeter in the world. We aimed at reviewing key studies and planning further research directions using the weighable lysimeters in Korea. In response to climate changes, environmental issues, and policies for sustainable agriculture, the experiments using a lysimeter were performed to better understand the nutrient leaching loss in the soils. The research topics were about crop rotation, soil amendment, nitrification inhibitors and what were better practices for reducing nutrient leaching including nitrogen. In addition, some researches focused on developing optimal models to predict the nutrient leaching loss in the soils that have a variety of environments. Current study suggests that the studies of the nutrient leaching loss combined with water dynamics using weighable lysimeters in Korea are to be fostered so that they may provide scientific guidelines on the issues and policies such as sustainable agriculture, climate change, fertilizer recommendation, and nutrient balance. Lysimeter research topics on nutrient leaching in Korea and around the world. - COLLAPSE
    November 2020