• Article

    Effect of Rice Hull-Derived Biochar Application on Watermelon Growth, and Soil Physico-chemical Properties under Greenhouse
    Young-Sang Kim, Ki-Hyun Kim, Jong-Woo Han, Taek-Gu Jeong, Min-Ja Kim, and In-Jae Kim
    Biochar is a solid substance made by carbonizing biomass. Biochar can be added to the soil and used as a soil conditioner … + READ MORE
    Biochar is a solid substance made by carbonizing biomass. Biochar can be added to the soil and used as a soil conditioner to improve the function of the soil. This study was conducted to investigate the effect of rice hull-derived biochar application on the growth, yield and soil physico-chemical properties of the watermelon cultivated under greenhouse. Rice hull-derived biochar was tested with 0 (no treatment), 1,000, 2,000, and 4,000 kg per ha levels. Among the growth characteristics of watermelon harvest season, rice hull-derived biochar application thickened stem diameter and increased fresh weight. The weight of watermelon was the heaviest in 2,000 kg ha-1 rice hull-derived biochar application, and the sugar content of watermelon was 0.3 - 0.4°Brix higher than that of control 11.5°Brix. The watermelon yield was the highest at 52,990 kg ha-1 in 2,000 kg ha-1 rice hull-derived biochar application, which was higher than that of control. Changes in soil chemical properties of rice hull-derived biochar application were increased with pH, exchangeable K, Ca and Mg, but available phosphate acid was decreased. The bulk density decreased and the porosity increased with the rice hull-derived biochar application. These results suggest that the rice hull-derived biochar application to the watermelon cultivation area could improve the productivity of watermelon by improving the physico-chemical properties of watermelon cultivation area. Watermelon yield component and sugar content according to rice hull-derived biochar application. Treatments (kg ha-1) Fruit weight (kg ea-1) Fruit length (cm) Fruit width (cm) Fruit thickness (cm) Sugar content (°Brix) 0 7.9 c 28.6 b 23.9 b 1.0 a 11.6 b 1,000 8.3 b 29.1 a 24.5 a 1.1 a 12.0 a 2,000 8.6 a 29.2 a 24.5 a 1.1 a 12.0 a 4,000 8.3 b 28.7 b 24.3 ab 1.0 a 11.9 a Values within columns having the same letters are not significantly different at the 0.05 as determined by DMRT. - COLLAPSE
    31 August 2022
  • Article

    Growth Characteristics and Physiological Responses of Soybean (Glycine max L.) under Excessive Soil Moisture Stress
    Hyen Chung Chun, Sanghun Lee, Dong Hyok Gong, Won-Chan Kim, Sang-Hyeob Lee, and Ki Yuol Jung
    Due to global climate change and poor drainage soil characteristic in paddy fields, soybeans which are one of main upland crops in … + READ MORE
    Due to global climate change and poor drainage soil characteristic in paddy fields, soybeans which are one of main upland crops in Korea are prone to get stressed by excessive soil moisture during cultivation. Excessive soil moisture stress causes poor growth, yield loss, and disease to soybeans. In order to prevent damages by excessive soil moisture stress, it is important to understand responses of soybeans under excessive soil moisture condition. Therefore, this study investigated morphological and physiological responses of soybeans by excessive soil moisture at various growth stages; V2, R1, R3, R5 and whole growing period. Soybeans were planted and characteristics of photosynthesis, chlorophyll fluorescence and 1-Aminocyclopropane-1-carboxilic acid (ACC) were measured from leaves after excessive soil moisture treatment. After harvest, growth and yield components were measured. As a result, soybean showed the smallest stalk height from soybeans which had excessive soil moisture at V2 and whole growing period. On the other hand, the greatest yield loss occurred when excessive soil moisture applied at R5, while the smallest at R2 and whole growing period. Soybean leaves showed the smallest photosynthetic rate and stomatal conductance under excessive soil moisture condition. These decline continued at least 1 week and restored to the values of photosynthetic rate and stomatal conductance from soybeans with no stress. Soybeans under excessive soil moisture exhibited greater ACC values than one of no stress. These increment of ACC continued 2 weeks and diminished. Soybeans treated with excessive soil moisture at V2, R1, R3 and whole growing period had decrease in photosynthetic rate and increase in ACC values. These results can indicate that changes of ACC contents in soybean leaves may be used as indicator of excessive soil moisture stress. Distributions of 1-Aminocyclopropane-1-carboxilic acid (ACC) content from soybean leaves located at bottom with excessive soil moisture treatments at various growth stages; V2, R1, R3, R5, Whole (whole growing period) and Control (no excessive soil moisture treatment). - COLLAPSE
    31 August 2022
  • Article

    Effects of Continuous Use of Organic Materials on Watermelon (Citrullus vulgaris Schrad.) Yield and Soil Chemistry in Plastic Film House
    Jeong-Hyun Lim, Byung-Koo Ahn, Seung-Hyun Cho, Ju-Hyung Jeong, Eun-Young Lee, and Kyoung-Won Seo
    This study was conducted to evaluate the effect of application of various organic materials for long-term on the changes of soil chemical … + READ MORE
    This study was conducted to evaluate the effect of application of various organic materials for long-term on the changes of soil chemical properties and the quality and productivity of watermelon growing in the plastic film house. Five treatments were established as follows: straw alone (RS1, RS2) or mixed with Protaetia brevitarsis larvae manure (PLM), rice hull biochar (RHB), and wood crumb (WC), respectively. The soil pH and organic matter content increased, and the EC (Electrical conductivity) decreased significantly in the first year and showed a stagnation period after second year. The available P2O5 content increased until the second year and then decreased. Exchangeable K increased to the third year and then decreased, and exchangeable Ca decreased to the second year. Exchangeable Mg did not change until the third year, but decreased in the fourth year. The watermelon weight was the heaviest in the RS2+PLM plot in the first year and RS2+RHB plot in the second year, but there was no difference in the plot section in the third and fourth years. The sugar content increased with the long-term application of organic materials. Therefore, mixed application of Protaetia brevitarsis larvae manure, rice hull biochar, and wood crumb with rice straw for more than three years, to grow watermelons organically in the plastic film house, is considered effective in improving the soil environment and the yield and quality of watermelons. Changes of watermelon fruit weight and products weight as influenced by the applications of different management practices during the experimental years. Treatment Fruit weight (kg) Commodity weight (kg 10a-1) 1st Y 2nd Y 3rd Y 4th Y 1st Y 2nd Y 3rd Y 4th Y RS1 7.4 b 7.8 ab 7.8 a 9.1 a 4,691 a (89.3) 4,438 a (80.0) 4,539 c (81.0) 5,973 b (90.5) RS2 7.1 b 7.3 b 7.9 a 9.2 a 4,515 a (89.6) 3,082 b (60.9) 4,676 bc (82.2) 6,001 b (90.5) RS2+PLM 7.7 a 7.8 ab 8.2 a 9.7 a 4,864 a (89.1) 4,410 a (80.4) 5,131 a (86.9) 6,640 a (95.2) RS2+RHB 7.1 b 8.3 a 8.3 a 9.7 a 4,531 a (89.9) 4,637 a (79.6) 5,193 a (86.9) 6,657 a (95.2) RS2+WC 7.1 b 7.6 ab 8.0 a 9.3 a 4,455 a (88.4) 3,905 ab (73.2) 4,804 b (83.4) 6,334 a (95.2) RS1, 10 Mg ha-1 of rice straw; RS2, 20 Mg ha-1 of rice straw; RS2+PLM, 5 Mg ha-1 of Protaetia brevitarsis larvae manure; RS2+RHB, 10 Mg ha-1 of rice hull biochar; RS2+WC, 10 Mg ha-1 of wood crumb. Values in the parentheses are the product ratio (%). - COLLAPSE
    31 August 2022
  • Article

    Plant Growth and Partitioning of Dry Matter and Inorganic Elements in Highbush Blueberry (Vaccinium corymbosum L.) ‘Scintilla’ Grown with Different N and K Compositions of Nutrient Solution in Heated Greenhouse Cultivation
    Mi Geon Cheon, Seo Hyoun Lee, Kyung Mi Park, Seong-Tae Choi, Yeon Hyeon Hwang, and Young Ho Chang
    This study was conducted to improve a nutrient solution composition to grow southern highbush blueberry cultivar ‘Scintilla’ in a pot in the … + READ MORE
    This study was conducted to improve a nutrient solution composition to grow southern highbush blueberry cultivar ‘Scintilla’ in a pot in the heated greenhouse cultivation. From September in 2020 to late May (40 days after harvest) in 2022, young blueberry plants were supplied with different compositions of nutrient solution, a 25% increase (NK increase) and a 25% decrease (NK decrease) in N and K concentrations, compared with a nutrient solution for the unheated greenhouse cultivation (control). Fruit size was not consistently affected by the nutrient compositions in the two seasons. Fruit yield in both 2021 and 2022 increased by 14 - 22% for the NK increase, but decreased by 13 - 59% for the NK decrease, compared with the control. Total shoot length per plant was 28 - 56% longer for the NK increase than the control, while it was 33 - 47% shorter for the NK decrease. Total dry weight per plant increased by 25% for the NK increase, especially 2.4-fold greater in root, which contrasted with a 17% reduction for the NK decrease. 7.2% and 51.2% of the total dry weight of a plant were partitioned to root and fruit for the control, respectively. The root partitioning of the dry weight increased to 14.1% for the NK increase, while the fruit partitioning increased to 54.1% for the NK decrease. The NK increase resulted in 49% and 30% increases in the total N and K contents per plant, respectively, compared with those of the control, while the NK decrease caused 41% and 21% reduction in the respective total content. When N and K increased in the nutrient solution, the root partitioning increased with lower leaf and fruit partitioning of inorganic elements, compared with the control. However, the root partitioning decreased with higher fruit partitioning for the NK decrease. The result indicated that the NK 25% increase of nutrient solution helps promote root growth with higher nutrient absorption, increasing the whole plant growth and the yield. Dry weight and its partitioning in different parts of ‘Scintilla’ blueberry plants supplied with different N and K compositions of nutrient solution in two growing seasons. N and K composition Leaf (g plant-1) Shoot (g plant-1) Old branch (g plant-1) Cane (g plant-1) Root (g plant-1) Fruit (g plant-1) Total (g plant-1) Control 99.8 a (18.1) 89.2 ab (16.2) 22.3 a (4.0) 18.3 ab (3.3) 40.0 a (7.2) 282.3 ab (51.2) 551.9 ab (100) 25% increase 101.5 a (14.8) 101.8 a (14.8) 25.4 a (3.7) 20.0 a (2.9) 96.7 a (14.1) 342.2 a (49.8) 687.7 a (100) 25% decrease 80.4 b (17.6) 60.6 b (13.3) 15.1 a (3.3) 15.0 b (3.3) 38.3 a (8.4) 247.2 b (54.1) 456.7 b (100) Different letters in each column indicate significant difference at p ≤ 0.05. Plants were sampled on June 30, 2022, except fruits harvested on April 25. Numbers in parentheses are percentages of plant parts to whole plant weight in each treatment. - COLLAPSE
    31 August 2022
  • Article

    Distribution of Heavy Metals in Agricultural Soils Near Major Roads in Medium-Sized Cities
    Myeong Seok Jeong, Mina Lee, Chaw Su Lwin, and Kwon-Rae Kim
    Due to rapid urbanization, urban lands have been expanded into existing agricultural areas. With such spatial changes, agricultural lands in the expanding … + READ MORE
    Due to rapid urbanization, urban lands have been expanded into existing agricultural areas. With such spatial changes, agricultural lands in the expanding cities or peri-urban areas are easily exposed to contaminants generated by anthropogenic activities such as traffic. Therefore, this study aimed to investigate heavy metal concentrations in major roadside agricultural soils by distance in medium-sized cities, Jinju and Changwon, and to identify the influence of roadside dust on metal contamination. The roadside arable soils of paddy and upland, roadside tree soil, and roadside dust were sampled. In paddy, the heavy metal concentration changes by the distance from the road were not observed because of soil puddling and waterlogging. However, in upland, Cu and Zn concentrations gradually decreased with the increased distance from the road. In roadside dust, Cu and Zn concentrations were very high, exceeding Korean guidelines, which indicates roadside dust could be a primary source of Cu and Zn contamination in agricultural soils. Moreover, the roadside tree soil, which is not disturbed by agricultural activities, showed higher heavy metal concentrations in topsoil rather than subsoil, even though the soil was newly introduced for tree planting. This implies that road dust containing the metal contaminants may accumulate in the nearby soils. Many scientists have thought that eco-friendly compost is the main reason for increasing Cu and Zn in urban agricultural soils. However, roadside dust needs to be more focused on as a principal source of contamination. High concentration of Cu and Zn in roadside dust and decrease of Cu and Zn concentration with the increased distance from the road in an upland soil. - COLLAPSE
    31 August 2022
  • Article

    Prediction of Soil Carbon Contents Using Smartphone Images and Multiple Regression Analysis
    Yun-Gu Kang, Yeon-Kyu Sonn, Jae-Han Lee, Jin-Hyuk Chun, Chang-Hun Lee, and Taek-Keun Oh
    Soil carbon is an important factor in the process of mitigating climate change and solving greenhouse gas problems. However, the previous technology … + READ MORE
    Soil carbon is an important factor in the process of mitigating climate change and solving greenhouse gas problems. However, the previous technology for soil carbon content analysis required a lot of labor, time, and expensive equipment (i.e. an elemental analyzer). In this study, the disadvantages of previous analysis method were secured by using smartphone images and multiple regression analysis. To predict the soil carbon content, the color variables (e.g., RGB, CIE-L*a*b*, CIE-L*c*h*, and CIE-L*u*v*), gravimetric water content, and bulk density were used as statistical data. After Pearson’s correlation analysis, several variables that had high correlations were removed and then used. In addition, the result of variance inflation factor (VIF) analysis indicated that all variables should not cause multicollinearity problems. The predictive model was classified based on land use, and the predictive model for the entire sample was also derived. The adjusted coefficient of determination (Adj. R2), root mean square error (RMSE), and mean absolute percentage error (MAPE) were used to verify the predictive model. When the verification method was substituted for each predictive model, the reliability of the predictive model classified based on land use was high. Therefore, in order to predict the carbon content in the agricultural soil, it is efficient to assign each prediction model after classifying agricultural land. Comparison of the results of substituting the predictive model derived in this study. - COLLAPSE
    31 August 2022
  • Short Communication

    Differential Reponses of Electrical Conductivity and Chloride Concentration in Soil and Plant Extracts to Chemical and Organic Fertilizations in Salt-Affected Greenhouses
    Jaeyong Eom, Khok Pros, Kyoungyoung Kim, Yonggook Kim, Jeong Su Lee, Hongsik Na, Hyunjong Cho, Jaehong Shim, and Gwang Hyun Han
    While electrical conductivity (EC) and sodium adsorption ratio are commonly used to assess soil salinity, for detecting salinity responses during a growing … + READ MORE
    While electrical conductivity (EC) and sodium adsorption ratio are commonly used to assess soil salinity, for detecting salinity responses during a growing season, those indicators appear to be insensitive when the soils are already high in salinity. We found that the EC and chloride concentrations in soil extracts from salt-affected greenhouses did not show a significant difference in response to different fertilizations of tomato (with a high N demand and a low susceptibility to salinity) and lettuce (the opposite) over the growing season. The fields had been treated with chemical fertilizers or chemical fertilizers plus manure composts combined with food wastes to investigate salinity enhancement by the amendments. On the other hand, the regression lines between EC and chloride concentration could show differential responses in both soil and plant extracts to the doses and salinities of fertilizers. Therefore, using the relationships between EC and associated ions can provide a better insight into the salinity susceptibilities of soils and plants. Relationship between EC and chloride concentration in plant extracts: (a) comparison between tomato and lettuce fields fertilized with chemical fertilizers, (b) comparison between tomato and lettuce fields fertilized with food-waste combined manure compost. The p value represents the significance of the difference between the slopes. - COLLAPSE
    31 August 2022
  • Short Communication

    Protaetia brevitarsis Larvae Manure as an Organic Amendment for Cultivation of Lettuce and Red Pepper
    Kyong-Hee Joung, Byung-Man Yoo, Jong-Won Kim, Sung-Mun Bea, Seul-Bi Lee, Da-Hyun Jang, Young Han Lee, and Dong-Cheol Seo
    This study was conducted to investigate the effects of the application of Protaetia brevitarsis larvae manure (PM) on the growth lettuce ( … + READ MORE
    This study was conducted to investigate the effects of the application of Protaetia brevitarsis larvae manure (PM) on the growth lettuce (Lactuca sativa L.) and red pepper (Capsicum annuum L.). Crops were planted in pots containing silt loam soils and cultivated with the basal application of chemical fertilizer at a standard rate (10.0 kg N 10a-1, 5.9 kg P2O5 10a-1, 6.5 kg K2O 10a-1, and calcium carbonate 170 for lettuce and 10.3 kg N 10a-1, 11.2 kg P2O5 10a-1, 9.1 kg K2O 10a-1, calcium carbonate 170 for red pepper) and PM at three rates (0, 540, and 1,080 kg) in pots (1/5000a). The growth of lettuce and red pepper increased with increased application of PM. Our results suggest that PM can be used as organic amendment for crop cultivation. Protaetia brevitarsis larvae manure (PM) and effect of Protaetia brevitarsis larvae manure application on lettuce and red pepper. (left) Protaetia brevitarsis larvae manure; (middle) Fertilizer injury degree of lettuce; (right) Fertilizer injury degree of red pepper. CF, chemical fertilizer; CFP1, CF + Protaetia brevitarsis larvae manure 540 kg 10a-1; CFP2, CF + Protaetia brevitarsis larvae manure 1,080 kg 10a-1. - COLLAPSE
    31 August 2022
  • Short Communication

    Conversion Factors for Electrical Conductivity of 1:5 Soil-Water Extracts to Saturated Paste of Reclaimed Tideland Soils are Affected by Sand Contents
    Bo-Seong Seo, Kwang-Seung Lee, Hyun-Jin Park, Young-Jae Jeong, Nuri Baek, Se-In Lee, Kwang-Sik Yoon, and Woo-Jung Choi
    Electrical conductivity (EC) of saturated soil paste extracts (ECe) is a standard measure for soil salinity assessment. However, due to … + READ MORE
    Electrical conductivity (EC) of saturated soil paste extracts (ECe) is a standard measure for soil salinity assessment. However, due to the difficulty of ECe measurement, EC of the extracts of 1:5 soil:water ratio (EC1:5) is widely used, and thus conversion of EC1:5 to ECe is often required. However, the conversion factor varies widely being affected by many soil factors including soil texture though such variation has rarely been investigated. This study was conducted to explore the effect of soil texture (particularly sand content) on the EC conversion factor using soil samples (n = 628) from 19 reclaimed tidelands (RTLs) located in the coastal areas of Korea. The conversion factors ranged from 4.6 to 9.9 (average 7.5) and the conversion factors were positively correlated with the average sand content of the RTL (r2 = 0.48, P < 0.001) except for three RTLs which have extremely low sand contents. The increased EC conversion factors for soils with higher sand contents should be ascribed to decreased saturated water contents for ECe. Our results demonstrate the critical influence of sand content on the EC conversion factor by highlighting the necessity of consideration of sand content for EC conversion factor. Correlation between EC1:5 and ECe of soils collected from reclaimed tideland. The slope (7.5) indicates that the conversion factor from EC1:5 to ECe is 7.5. - COLLAPSE
    31 August 2022