• Article

    Influences of Phosphogypsum Application on Soil Property and Yield and Quality of Onion (Allium cepa L.)
    Young-Nam Kim, Ju Young Cho, Young-Eun Yoon, Hyoen Ji Choe, Mi Sun Cheong, Mina Lee, Kwon-Rae Kim, and Yong Bok Lee
    Phosphogypsum (PG) is a by-product obtained in the process of manufacturing phosphoric acid (H3PO4). In general, PG is characterized ... + READ MORE
    Phosphogypsum (PG) is a by-product obtained in the process of manufacturing phosphoric acid (H3PO4). In general, PG is characterized mainly by gypsum, phosphate, sulphate, fluoride etc. Considering the nutritional composition, PG has been globally used as soil fertilizer or amendment in agriculture for decades. This study aimed to investigate effects of PG application on soil properties and yield and quality of onion (Allium cepa L.) and to seek proper rate of PG application in a field. We applied PG into a field with four different levels: 0% (control), 50% (PG50, 104 kg 10a-1), 100% (PG100, 208 kg 10a-1), and 150% (PG150, 312 kg 10a-1). Also, oyster shell (OS) included as a comparable and chemical fertilizer (N-P-K = 8.4-37.9-8.0 kg 10a-1) was supplied into soil of all treatments. Following onion cultivation for 7 months, there was a significant change in soil pH. Indeed, PG application was more likely to lower pH relative to control. With increase in PG application rate, soil EC increased and the maximum value (1.93 dS m-1) was found in soil of PG150. In PG100 and PG150, concentration of exchangeable Ca (Ex. Ca) increased by 5% and 10%, respectively, whilst other treatments representing reduction in the Ex. Ca concentration. In addition, PG application affected concentration of water soluble Ca across the soil profile (up to 70 cm depth) and, in particular, the higher the PG application rate the higher the concentration of water soluble Ca. Similarly, water soluble S had same trend with water soluble Ca in the present study. With increase of PG application rate, yield of onion increased but decreased in PG150 which is the highest rate of PG application. Also, the plant’s uptake for N, P, Ca, K, and S affecting yield, resistance to pathogen and pest, and quality of the crop increased in PG50 and PG100. Moreover, concentrations of total amino acids, cysteine and methionine in onion bulbs that are strongly associated to S uptake increased by PG applications. The increased concentrations of amino acids with PG applications might improve yield, quality, and favor of onions. These results suggest that PG supply could have a potential to enhance soil fertility, contributing to improvement of yield and quality of onions. Further studies are needed to maximize efficiency of PG supply in agricultural lands. Vertical movement of Ca and SO4 across the soil profile following phosphogypsum application. - COLLAPSE
    May 2021
  • Article

    Effects of Co-application of Biochars and Composts on Lettuce Growth
    Jae-Hyuk Park, Se-Won Kang, Jin-Ju Yun, Seung-Gyu Lee, So-Hui Kim, Jun-Seok Beak, and Ju-Sik Cho
    The effect of biochar and organic resource applications on lettuce cultivation was investigated. Treatment conditions of pot experiment were designed with CN ... + READ MORE
    The effect of biochar and organic resource applications on lettuce cultivation was investigated. Treatment conditions of pot experiment were designed with CN (control), IF (inorganic fertilizer), BC400-1 (Rice husk biochar 400°C 1%), BC400-1+CP (Rice husk biochar 400°C 1%+compost), BC400-4 (Rice husk biochar 400°C 4%), BC400-4+CP (Rice husk biochar 400°C 4%+compost), BC600-1 (Rice husk biochar 600°C 1%), BC600-1+CP (Rice husk biochar 600°C 1%+compost), BC600-4 (Rice husk biochar 600°C 4%) and BC600-4+CP (Rice husk biochar 600°C 4%+compost). The lettuce fresh weight in IF, BC400, and BC600 treatments increased 185, 101-219, and 83-138%, respectively, over that in CN treatment. Total amount of nutrient uptake in lettuce increased in the order BC400-4+CP > IF ≒ BC600-4+CP ≧ BC400-4 ≧ BC400-1+CP ≧ BC600-1+CP ≧ BC600-4 ≒ BC600-1 ≧ BC400-1 ≒ CN treatments. Considering the results of fresh weight, number of leaves, and nutrients of lettuce, the growth of lettuce was most effective in BC400-4+CP treatment, over that in the IF treatment. Application of combined biochar and compost significantly affected the chemical characteristics of field soil after lettuce harvest. In addition, the positive effects of biochar and compost in soil were related to improved nutrient availability-related parameters such pH and CEC. Therefore, proper application of biochar with compost is effective at improving lettuce cultivation and can benefit the soil environment. Biochar production and lettuce cultivation. - COLLAPSE
    May 2021
  • Article

    A Study on the Analysis of the Biochemical Methane Potential of the Kenaf (Hibiscus cannabinus)
    Tae-Bong Kim, Kook-Sik Shin, Jae Ho An, and Young-Man Yoon
    Hibiscus cannabinus is a forage crop having high biomass production. In this study, biochemical methane potential (BMP) assay of Hibiscus cannabinus was ... + READ MORE
    Hibiscus cannabinus is a forage crop having high biomass production. In this study, biochemical methane potential (BMP) assay of Hibiscus cannabinus was carried out to evaluate the availability as energy croop by anaerobic digestion. Methane potential of Hibiscus cannabinus were 0.202 and 0.181 Nm3 kg-1-VSadded at the substrate to inoculum (S/I) ratios of 0.3 and 0.5, respectively. Hibiscus cannabinus showed a low methane conversion rate due to its high fiber content. When the nutrient medium was added to the batch anaerobic reactor in order to increase the methane conversion efficiency of Hibiscus cannabinus, methane potential of Hibiscus cannabinus were increased to 0.313 and 0.253 Nm3 kg-1-VSadded at the S/I ratios of 0.3 and 0.5, respectively. Cumulative methane potential curves of the Hibiscus cannabinus (Parallel first order kinetics model). - COLLAPSE
    May 2021
  • Article

    Study of Methodology Estimating the Net Nitrogen Balance for the Management of Regional Nutrient Balance
    Jun-Hyeong Lee, Jae Ho An, Eulsaeng Cho, and Young-Man Yoon
    The Ministry of Environment (ME) is promoting the introduction of the regional nutrient management system as the target year for 2021 in ... + READ MORE
    The Ministry of Environment (ME) is promoting the introduction of the regional nutrient management system as the target year for 2021 in order to manage the amount of nutrients (nitrogen and phosphorus) input to agricultural land at an appropriate level. The nutrient balance of Korea has been reported to be 212 kg ha-1 of nitrogen and 46 kg ha-1 of phosphorus, and the nitrogen balance is at the highest level in the OECD member countries. Nutrient input to agricultural land is composed of inorganic fertilizers (chemical fertilizers), composted organic fertilizers (livestock manure compost, etc.), and organic fertilizers (oil meal fertilizers, etc.). Fertilizer application could be limited in the region which excess nutrients (nitrogen and phosphorus) have been loaded to agricultural land. Nutrient input to agricultural land have a beneficial function improving soil fertility and productivity of crops. However, excess nutrient input to agricultural land might have a drawback releasing non-point sources to water system such as river and lake. Therefore, it is necessary to consider both the environmental effect of reducing non-point contaminants due to the reduction of input nutrients in agricultural land and the agricultural production aspect of reducing agricultural productivity by setting the regional nutrient balance management goals. In this study, the methodology to estimate crop yield response according to regional nitrogen loading rate was established for the reasonable management of regional nitrogen balance and regional appropriate nitrogen balance index (net nitrogen balance) was estimated considering the affect of agricultural production. Based on our results, it was possible to understand the effect of regional nutrient management on agricultural production and the outflow of nutrients to water systems by methodology estimating the net nitrogen balance for the management of regional nutrient balance. Regional classification for the nutrient balance management by NNB (net nitrogen balance). - COLLAPSE
    May 2021
  • Article

    Effect of Cultivation of Rotation Crops on Soil Physico-chemical Properties and Yield of Watermelon in Greenhouse
    Young-Sang Kim, Ki-Hyun Kim, Taek-Gu Jeong, Jong-Woo Han, Ik-Jei Kim, Tae-Il Kim, Young-Ho Kim, and Yong-Sup Song
    Most of the plastic vinyl house areas are filled with many fertilizer materials for the year-round cultivation of crops. The sequence cultivation ... + READ MORE
    Most of the plastic vinyl house areas are filled with many fertilizer materials for the year-round cultivation of crops. The sequence cultivation of specific crops is deficient in essential elements, salt accumulation, excess, and deficiency of nutrients. The objective of this study was to investigate soil properties and watermelon productivity in plastic film houses according to the short-term crop rotation in the continuous watermelon-cultivated soils. The short-term rotation crops selected were watermelon, pumpkin, sesame, spinach, radish and soybean. The results are as follows. In the following crop rotation of soybean and sesame, the volume density decreased, the porosity increased, and the ratio of the solid phase in the soil was lowered. After the experiment pH and exchangeable Mg increased in all treatments irrespective of the crop rotation, and EC and available phosphorus decreased with sesame, spinach, radish, and soybean rotation. Soil organic matter (SOM) increased in soybean and sesame rotation treatments and decreased in watermelon, pumpkin, spinach, and radish rotation treatments. Among the growth characteristics of watermelon, stem diameter, plant length, and fresh weight showed good growth in spinach, radish, and soybean rotation treatments, and watermelon continuous cropping and pumpkin rotation treatment generally showed poor growth. The yields of watermelon were increased by 7 - 8% to 45,620 and 46,030 kg ha-1, respectively, in radish and soybean rotation treatments, compared with 42,730 kg ha-1 of watermelon continuous cropping treatment. These results suggest that the addition of short-term rotational crops such as radish and soybean crops could improve the physico-chemical properties of the soil and improve watermelon productivity. Changes of soil chemical properties according to rotation crop after experiment. Rotation crop system (spring + autumn) pH (1:5) EC (dS m-1) OM (g kg-1) Av. P2O5 (mg kg-1) Exch. cations (cmolc kg-1) K Ca Mg W + Watermelon 2015 6.2 b 4.60 ab 22.5 b 315 b 0.34 a 8.5 ab 2.7 ab 2016 6.3 ab 4.63 ab 20.8 bc 320 b 0.37 ab 8.6 ab 2.9 a 2017 6.3 ab 4.80 a 17.8 c 327 ab 0.36 ab 8.4 ab 2.7 ab W + Pumpkin 2015 6.2 b 4.50 ab 23.2 b 324 ab 0.33 ab 8.5 ab 2.7 ab 2016 6.2 b 4.70 a 22.1 b 341 a 0.41 a 8.5 ab 2.9 a 2017 6.4 ab 4.82 a 16.0 c 354 a 0.42 a 8.6 ab 2.9 a W + Sesame 2015 6.3 ab 4.20 bc 22.4 b 302 bc 0.29 ab 8.3 b 2.6 b 2016 6.4 ab 3.65 cd 23.7 ab 288 c 0.30 ab 8.3 b 2.5 bc 2017 6.4 ab 3.40 cd 24.6 a 265 c 0.27 ab 8.2 bc 2.4 bc W + Spinach 2015 6.3 ab 4.20 bc 22.0 b 322 b 0.30 ab 8.5 ab 2.8 ab 2016 6.4 ab 4.07 c 21.5 b 332 ab 0.25 b 8.5 ab 2.9 a 2017 6.5 a 3.70 cd 18.9 c 347 a 0.22 b 8.6 ab 2.9 a W + Radish 2015 6.3 ab 4.30 b 23.1 ab 310 b 0.29 ab 8.3 b 2.5 bc 2016 6.3 ab 3.72 cd 19.6 c 282 c 0.28 ab 8.1 c 2.3 c 2017 6.4 ab 3.32 d 20.0 bc 277 c 0.22 b 8.0 c 2.3 c W + Soybean 2015 6.2 b 4.10 c 21.8 bc 308 bc 0.28 ab 8.6 a 2.8 ab 2016 6.3 ab 3.70 cd 22.8 b 301 bc 0.25 ab 8.7 a 2.7 ab 2017 6.4 ab 3.20 d 25.4 a 285 c 0.26 ab 8.7 a 2.5 bc W: watermelon, Means followed by the same letter are not significantly different at 0.05 probability level according to Duncan’s multiple range test. - COLLAPSE
    May 2021
  • Article

    Changes in Soil Chemical Properties of Rice Paddy, Upland Field, and Greenhouse in Incheon from 2015 to 2019
    Seong Heo
    This study was performed with the monitoring data of soil chemical properties of rice paddy, upland field and greenhouse soils in Ganghwa ... + READ MORE
    This study was performed with the monitoring data of soil chemical properties of rice paddy, upland field and greenhouse soils in Ganghwa, Incheon metropolitan city from 2015 to 2019. Soil pH values tended to increase gradually in three soils, but there was no significant change in that of greenhouse soil. The concentration of organic matter (OM) and available phosphate (Av. P2O5) have fluctuated from 2015 to 2019, showing significant differences. In 2019, the average value of OM and Av. P2O5 were distributed within the appropriate level suggested by Rural Development Administration. In rice paddy field, the available silicate (SiO2) were found to be proper within the standard concentration every year. The contents of exchangeable cations were higher than the proper standard, showing significant differences among the years, except greenhouse soil. The mean concentration of EC for five years in upland and greenhouse soils were 2.5 and 5.9 dS m-1 above the proper standard. The optimal frequencies of pH were 46.8% and 47.1% at rice paddy and upland soil, but the excessive frequency ratio of pH was 48.5% at greenhouse soil in 2019. The exchangeable cations seemed to be seriously disproportionate exceeding the optimal level by 95%. In Pearson correlation matrix, the value of exchangeable Ca had a significantly positive correlation with exchangeable Mg content at upland and greenhouse soils. By principal component analysis, the exchangeable K, Mg and OM could distinguish between greenhouse and other soils on the first principal component and the pH and Av. P2O5 could differentiate between rice paddy and upland soils on the second principal component. Scatter plot of chemical properties investigated from rice paddy (P), upland (U) field and greenhouse (F) soils from 2015 to 2019. - COLLAPSE
    May 2021
  • Article

    Estimation of Optimum N Fertilizer and Sowing Rate for Italian Ryegrass Seed Production in the Saemangeum Reclaimed Land
    Hui Su Bae, Hyeonsoo Jang, Seung Hyeon Ahn, Uk Han Kim, Jong Tak Youn, and Doug Young Chung
    Italian ryegrass (Lolium multiflorum Lam.) was cultivated in a field experiment, on sandy loam soil of the Saemangeum reclaimed land, under different ... + READ MORE
    Italian ryegrass (Lolium multiflorum Lam.) was cultivated in a field experiment, on sandy loam soil of the Saemangeum reclaimed land, under different sowing rates and N fertilizer levels to estimate the optimum N fertilizer requirement and the most suitable sowing rate for seed production. The experiment was conducted in a split-plot design with four replications. The main-plots were four sowing rates of 10, 20, 30, and 40 kg ha-1 and sub-plots were five N fertilizer application rates of 0, 45, 90, 135, and 180 kg ha-1. Harvest index decreased with increasing sowing and N fertilizer rate. The highest N use efficiency was obtained at 10 kg ha-1 sowing rate and 45 - 90 kg ha-1 N fertilizer application rates. Maximum seed yield of Italian ryegrass based on the regression curve of N fertilizer application level was 102 kg ha-1 and was decreased with further N application. Economically, optimum rates of N application ranged from 70 to 101 kg ha-1 depending on the sowing rate. Results from this experiment, could therefore inform producers of the best combination of sowing and N fertilizer rates needed to increase profitability of Italian ryegrass seed production alongside preventing N loss. However, further research will be necessary to elucidate on increasing seed quality and stability of cultivation under various environmental conditions. Relation between IRG seed yield and nitrogen fertilization rates according to the regression curve in the Saemangeum reclaimed tidal land. - COLLAPSE
    May 2021
  • Article

    Research on Paleotopographic Soil Map Analysis of Historic Sites and Decoding of Aerial Photographs
    Euihaeng Heo and Wooyoung Chang
    In research on archaeology, locating archaeological relics involves a methodology called “paleotopographic analysis.” In this analysis, past aerial photographs are decoded and ... + READ MORE
    In research on archaeology, locating archaeological relics involves a methodology called “paleotopographic analysis.” In this analysis, past aerial photographs are decoded and combined with a synthesis of topographical data such as soil and geological maps and archaeological stratum data. However, there continues to be a lack of methodological research and discussions on validating the analysis. There is a need, therefore, to establish the criteria for geological classification and the reading of a site’s morphological features to present objective evidence of paleotopographic analysis through aerial photographs. In this respect, soil maps of the Soil and Environmental Information System of Korea published by the Rural Development Administration can be used as an important source of analysis. The soil map applies methods similar to paleotopographic analysis, which helps in identifying the macroscopic topographical features of a site. Once the classification of topography via soil maps is complete, the fine topography and traces of historical sites can be identified by decoding aerial photographs. The classification of micro-geographical features can be read based on color tone and color and types of arable land. Topographic classification largely divides sites into mountainous areas and lowlands, and finer topographical features can be identified within this. Analyzing the color tone and color used in different shades of black and white can help in identifying the different types of landscape depicted by them. On farmlands, Buried fine topographical features can be examined by observing and analyzing the direction of ridges between cultivation fields. Fine topographies identified thus based on these decoding criteria should again lead to the reading and interpretation of natural and artificial traces. Human activities are observed by (a) distinguishing traces of artificial structures in mountainous terrains; (b) identifying landforms, fine highlands, fine lowlands, and waterways in lowlands; and (c) traces of artificial landforms. Once the criteria and interpretation of these decoding results are clarified, discussions on human settlements based on topography as well as on finding archaeological relics underneath the soil become feasible. Example of Gyeongju topography classification. : Hwang and Yoon (2013), : National Academy of Agricultural Sciences (2014), : Chang (2020). - COLLAPSE
    May 2021
  • Article

    Changes in Paddy Soil Properties and Rice Yield as Affected by Application Time of Granular Livestock Manure Compost
    Do-Young Ko, Byung-Koo Ahn, Hyung-Cheol Moon, and Hyong-Gwon Chon
    Pelletized livestock manure compost is easy to handle and thus increasingly used as an orgranic amendment. The effectiveness of granular livestock manure ... + READ MORE
    Pelletized livestock manure compost is easy to handle and thus increasingly used as an orgranic amendment. The effectiveness of granular livestock manure compost (GLMC) was investigated at different times, with 5, 15, 25 and 35 days before transplanting rice plots. After two years of administration of GLMC, pH, available P2O5, exchangeable K, Ca, and Mg decreased and organic matter content increased, compared to the soil before the test. The faster the treatment time of GLMC, the lower the organic matter content. But the T-N was the same in the control, 5 and 15 days before transplanting rice plots. In flooded soil, the N mineralization of GLMC proceeded 2 weeks later than inorganic fertilizers and 1 week later than livestock manure compost. Rice growth and quantity showed similar results in control and 25 days before transplanting rice plot. When GLMC was used, the protein content of white rice was lower than that of control plot, and there was no difference in amylose, whiteness, and palatability. The correlation between the white rice quantity and the treatment time of the GLMC was Y = -0.075X2 + 3.982X + 492.74 (R2 = 0.7722), and the treatment time to obtain the highest quantity of white rice was 26.5 days. Relationship between rice yield and treatment time of granular livestock manure compost. - COLLAPSE
    May 2021
  • Short Communication

    Estimation of Soil Organic Carbon (SOC) Stock in South Korea Using Digital Soil Mapping Technique
    Seong-Jin Park, Soon-Ik Kwon, Seong-Heon Kim, Jaehong Shim, Yun-Hae Lee, and Taek-Keun Oh
    Estimation of soil organic carbon (SOC) stocks is highly relevant considering that SOCs is the central driver in soil fertility and climate ... + READ MORE
    Estimation of soil organic carbon (SOC) stocks is highly relevant considering that SOCs is the central driver in soil fertility and climate change mitigation. This study aims to (i) evaluate the SOC stock in the first 0 - 30 cm and 0 - 100 cm soil layer on a national scale from spatially explicit explanatory environmental variables and a legacy soil database and (ii) the spatial distribution of SOCs at national scale through digital mapping technique. A spatial model was established using Cubist, a decision tree algorithm and based on soil data (s factor), climatic (c factor), topographic (r factor). Results showed that soil texture, soil parent, mean annual precipitatio and elevation were the most important predictors of SOCs. The Cubist prediction model had a Root Mean Squared Error (RMSE) equal to 19.5 at 0 - 30 cm, 68.7 at 0 - 100 cm. The predicted mean SOC stock from fitted models was 35 ton C ha-1 for 0 - 30 cm depth, 87 ton C ha-1 for 0 - 100 cm soil depth. In total, soil stored approximately 330 Mt C for 0 - 30 cm depth and 842 Mt C for 0 - 100 cm depth. Uncertainty (95%) and spatial distribution map of predicted SOC stocks (ton C ha-1, 0 - 30 cm soil depth) in South Korea. - COLLAPSE
    May 2021
  • Short Communication

    Effects of Equilibrium Time on Electrical Conductivity Measurements Using Soil-Water Extracts and Soil Saturated Paste
    Bo-Seong Seo, Young-Jae Jeong, Kwang-Seung Lee, and Woo-Jung Choi
    Electrical conductivity (EC) is a robust indicator of soil salinity. In South Korea, EC of 1:5 of soil:water extracts (EC ... + READ MORE
    Electrical conductivity (EC) is a robust indicator of soil salinity. In South Korea, EC of 1:5 of soil:water extracts (EC1:5) and soil saturated paste extracts (ECe) are often used. The standard shaking time is 0.5 hr for EC1:5 and standing time after soil saturation is 16 hrs for ECe. In this study, we investigated the effects of equilibrium time (shaking and standing time for EC1:5 and ECe, respectively) to test if the standard time is enough for precise and accurate measurement of EC. Two soils (silt loam and sandy loam) with seven levels of EC were prepared by adding salt solutions (1, 2, 4, 8, 12, 16, and 24 dS m-1) to the soils. The soils were used for experiments after 2-months aging. The EC1:5 was measured after shaking soil-water mixture for 0.5, 1, 2, and 3 hrs, and ECe was determined after standing the saturated soils for 4, 8, 16, 24, and 48 hrs. The results showed that 4 hrs of standing time for ECe are sufficient for most saline soils regardless of soil texture. However, occasional occurrence of large variations in ECe up to 25% indicates a necessity of longer (e.g., 24 hrs) standing time for some soils. Therefore, for long-term monitoring of ECe, it may be necessary to determine site-specific standing time for ECe. Unlike ECe, the variations in EC1:5 with shaking time was negligible. However, for soils treated with solution of high EC (24 dS m-1), the variability increased up to 6% variations. Therefore, it may be necessary to increase shaking time to 1 hr to ensure a precise measurement of EC1:5 particularly for high-saline soils. For precise measurement of EC by achieving equilibrium of ions, shaking for 1 hr is required for EC1:5 and standing for 24 hrs is appropriate for ECe. - COLLAPSE
    May 2021