• Article

    Rainfall Erosivity Factor of Korean Soils Estimated by Using USLE under Climate Change
    Min Woo Kang, Dong Jin Kim, Kyoungjae Lim, and Sang Soo Lee
    Sustainable soil environment along with available water resources is critical for food security and agricultural productivity. The Korea territory consists of 65 ... + READ MORE
    Sustainable soil environment along with available water resources is critical for food security and agricultural productivity. The Korea territory consists of 65% of mountainous topography and the variability of rainfall is rapidly increasing due to climate change, thereby increasing a risk of soil erosion. Soil erosion by water has been estimated using the empirical equations with accumulated data over the time in the U.S. since 1930 s, representatively the Universal Soil Loss Equation (USLE) published by the U.S. Department of Agriculture (USDA); however, this empirical model is not always well fitted to soil erosion estimations in other countries because of different regional characteristics. Moreover, application of the conventional equations of soil erosion like USLE for estimation of soil erosion under climate change is not appropriate. This study employed the data of rainfall erosivity for past 30 years (1981 - 2010) and recent 10 years (2011 - 2020) observed from ≤60 observations in Korea and compared them to evaluate the effect of climate change on soil erosion in Korea. The relationship between rainfall erosivity and daily maximum precipitation was positive (R2 = 0.66), but indicated different central tendencies between data for past 30 years and recent 10 years. The values of rainfall erosivity in the southeast part of the country, e.g., Daegu, Ulsan, and Busan, have increased over the last 10 years compared to those over the past 30 years. The more effective and practical estimation technique of soil erosion should further be developed to ensure the climate change effects in Korea. Mapping the average annual R factor for each decade. - COLLAPSE
    August 2021
  • Article

    Estimation of Water Retention Characteristics Depending on the Particle Sizes of Perlite Using van Genuchten Equation with Retention Curve Program
    Chul Soon Lim, Kyo Suk Lee, Dong Sung Lee, Hyun Gyu Jung, Beong Deuk Hong, Yoon Jeong Kim, and Doug Young Chung
    The estimation of water retention for perlite particles, which are used as growth media need to set up for proper water management ... + READ MORE
    The estimation of water retention for perlite particles, which are used as growth media need to set up for proper water management strategy due to uncertain available water proportion during growth period of vegetable crops in a greenhouse. The water retention curves (WRC) expressed as volumetric water content (θv) were constructed with five different sizes of the expanded perlite after fully saturating and packing the perlite in open-ended metal cubes at 11 levels of matric potentials from 0 to -1,500 kPa. The best fitted four parameter values (θs, θr, n, α) of the van Genuchten model (vG model) for the substrate samples were obtained using the Retention Curve Program (RETC) based on the values measured water content at the corresponding matric potentials. The particle size corresponding to 36.8 percentage by mass of particles was 0.80065 mm. The calculated uniformity coefficient and the coefficient of gradation for the perlite were 1.962 and 2.51 mm, respectively. Measured water contents at each matric potential increased with decreasing particle size of perlite while the difference of water content between saturation (θs) and residual state (θr) increased with increasing particle size. The mean R2 for all sizes of the perlite particle was suitable to predict θv because the measured data points did not vary around the estimated regression line. Therefore, PTF performance based on van Genuchten (vG) equation using data set including perlite particle size can be applicable to estimate water retention in perlite particles. Water retention curves measured at the water potential ranging from 0 to -1,500 kPa for five levels of particle size of expanded perlite. - COLLAPSE
    August 2021
  • Article

    Applicability of Conventionally Recommended Fertilizer Rates for Potato Cultivated in Saemangeum Reclaimed Land in the Fall Season
    Kwangseung Lee, Kangho Jung, Jinhee Ryu, and Suhwan Lee
    It is important to increase the area of potato cultivation in the fall season for a stable year-round supply system in Korea ... + READ MORE
    It is important to increase the area of potato cultivation in the fall season for a stable year-round supply system in Korea. Saemangeum reclaimed land has the potential to extension of potato cultivation area with appropriate practices. This study was performed to test applicability of fertilizer recommendation in southern coastal area to the Saemangeum area. Two experiments were conducted: one experiment compared the yield response of potato between standard rates of N-P-K (SR) and recommendation rates of N-P-K based on soil test (STR) and the other experiment analyzed yield response to 4 different levels of N, P, K, respectively. The potato yield in SR was 6.05 Mg ha-1 on average and varied from 1.68 Mg ha-1 to 11.80 Mg ha-1. The potato yield in STR, meanwhile, ranged from 8.13 Mg ha-1 to 12.17 Mg ha-1 with a mean value of 9.65 Mg ha-1. Potato yield was increased linearly with N fertilization rates but P and K fertilization did not have any significant effect on potato growth. The N fertilization rate (NFR) and the soil available phosphate content (Av. P2O5) had significant positive corelation with potato yield (p < 0.01). Based on stepwise multiple regression analysis, partial regression coefficient was 0.30 for NFR and 0.08 for Av. P2O5; Y = 19.6 X1 + 34.9 X2 + 1,410, where Y, X1, and X2 mean potato yield, NFR, and Av. P2O5, respectively. Conclusively, STR was strongly recommended for potato in the Saemangeum reclaimed land and the conventional standard fertilization rate was hardly applicable to the area, especially for nitrogen. Potato product by fertilization rates in the fall season. The standard rates were 120, 106, and 156 kg ha-1 for N, P2O5, and K2O. The other two were provided as the standard rates. - COLLAPSE
    August 2021
  • Article

    Large Scale Cultivation of Bacillus velezensis CE 100 and Effect of Its Culture on Control of Citrus Melanose Caused by Diaporthe citri
    Dong Ryul Lee, Chaw Ei Htwe Maung, Tae Gyu Choi, and Kil Yong Kim
    Diaporthe citri is an important fungal pathogen which causes melanose in various citrus growing regions of the world. In our study, control ... + READ MORE
    Diaporthe citri is an important fungal pathogen which causes melanose in various citrus growing regions of the world. In our study, control of D. citri was performed by using effective biocontrol agent, Bacillus velezensis CE 100. Mycelial growth of D. citri was highly restricted by strain CE 100 in dual culture plates. Our study demonstrates large-scale inoculation of strain CE 100 in non-sterilized PB medium. In addition, bacterial culture filtrate (BCF) of strain CE 100 from the large-scale culture showed better growth inhibition of D. citri than those from small-scale culture in the laboratory. Moreover, microscopic observation revealed that hyphal morphology of the pathogen was significantly affected by BCF, probably because of various cell-wall degrading enzymes and metabolites produced by strain CE 100. In addition, 50% BCF of strain CE 100 inhibited D. citri conidial germination by over 80%. Treatments, applied by foliar spray with fungicide and strain CE 100 culture, significantly lowered melanose disease incidence more than did control. The results of this study indicate that large-scale culture of strain CE 100 was effective for control of D. citri by means of adequate active metabolites and cells. Therefore, we demonstrate biocontrol applicability of B. velezensis CE 100 on control of citrus melanose by developing a low-cost PB medium using affordable large-scale fermenter. Effect of different treatments on melanose disease incidence on leaves of mandarin plants at 20 days after inoculation with D. citri. Statistical comparison between treatments was done by least significant difference (LSD) test at p < 0.05 level. Means with the same letter are not significantly different from each other. *Con- Control, CE 100- Treatment with B. velezensis CE 100 culture, F- Treatment with fungicide - COLLAPSE
    August 2021
  • Article

    Pollution Load Index for Heavy Metals of Agricultural Soils Adjacent to Industrial Complexes in the Jeon-Buk Regions of Korea
    Sorakon Suwanmanon and Ki In Kim
    Monitoring heavy metal concentrations in agricultural soils close to industrial complexes plays a critical role in ascertaining the safe agricultural environment in ... + READ MORE
    Monitoring heavy metal concentrations in agricultural soils close to industrial complexes plays a critical role in ascertaining the safe agricultural environment in Korea and its product qualities. Objective of this study was to assess the heavy metal concentrations in agricultural soils close to industrial complexes. Fifteen industrial complexes in 7 counties in Jeon-Buk Province (Gochang, Iksan, Jeongeup, Gimje, Imsil, Jangsu, and Wanju) were selected for monitoring soil heavy metal concentrations in 2019. The soil samples were analyzed for 7 heavy metals, including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) within 500 meter and 1,000 meter radius at each industrial complex boundaries. Heavy metal concentrations in soils ranged from 0.3 to 8.0 mg kg-1 for As, from 0.2 to 1.5 mg kg-1 for Cd, from 1.7 to 62.9 mg kg-1 for Cr, from 1.4 to 22.5 mg kg-1 for Ni, from 4.1 to 26.0 mg kg-1 for Pb, from 0.0 to 1.4 mg kg-1 for Hg, and from 25.9 to 283.5 mg kg-1 for Zn. Heavy metal concentrations in soils were lower than the levels of Soil Contamination Warning Standard (SCWS). The pollution index (PI) values of all seven heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) ranged from 0.1 to 0.4 for top and sub soils indicating that these soils are not polluted. The pollution load index (PLI) values using 7 heavy metals at each county ranged from 0.10 to 0.24 for top and sub soils and the number was categorized into Group 2 which is unpolluted. These results suggested that monitored agricultural soils near industrial complexes in Jeon-Buk province in 2019 were unpolluted by heavy metals and safe for agricultural activities. Descriptive statistics of heavy metal concentrations in agricultural soils near the industrial complexes in Jeon-Buk Province in Korea. Element As Cd Cr Cu Hg Ni Pb Zn --------------------------------------------------------------------------- (mg kg-1) --------------------------------------------------------------------------- Soil depth Top Sub Top Sub Top Sub Top Sub Top Sub Top Sub Top Sub Top Sub Average 3.1 3.0 0.9 0.8 14.8 14.7 16.4 15.2 0.01 0.01 9.9 9.7 12.3 12.2 73.1 68.2 Min. 0.4 0.3 0.2 0.3 1.8 1.8 3.7 3.4 0.00 0.00 1.4 1.5 4.6 4.2 25.9 31.4 Max. 8.1 8.0 1.6 1.3 48.9 63.0 45.7 43.1 0.04 0.04 22.3 22.5 25.6 26.1 283.5 199.0 Stdev. 1.7 1.6 0.2 0.2 7.4 7.8 8.4 7.5 0.01 0.01 4.8 4.6 3.7 3.5 29.6 23.3 C.V. (%) 53.7 53.9 27.8 26.6 50.1 53.2 51.4 49.2 140.2 140.7 48.3 47.3 29.9 29.1 40.5 34.2 Kurtosis -0.6 -0.6 -0.2 -0.6 1.8 8.5 2.0 2.6 3.0 6.2 -0.5 -0.5 0.6 1.5 17.5 7.4 Skewness 0.4 0.4 0.2 -0.1 0.8 1.6 1.3 1.4 1.7 2.1 0.4 0.4 0.3 0.6 3.1 2.0 SCWS limit 25 4 n/a 150 4 100 200 300 Number of above SCWS 0 0 0 0 0 0 0 0 Min., minimum; Max., maximum; Stdev., standard deviation; C.V., coefficients variations. Soil Contamination Warning Standard (SCWS) from Ministry of Environment (MOE) in Korea. - COLLAPSE
    August 2021
  • Article

    Optimal Fertigation Guide for Greenhouse Strawberry: Development and Validation
    Ye-Jin Lee, Seul-Bi Lee, and Jwakyung Sung
    Development of a customized fertigation guide for greenhouse crops is a very important means to attain soil quality control as well as ... + READ MORE
    Development of a customized fertigation guide for greenhouse crops is a very important means to attain soil quality control as well as a favorable crop yield. In this study, we tried to develop and validate the fertigation guide of greenhouse strawberry using crop growth and NPK uptake rates by the specific growth stage. To achieve these goals, we firstly applied 4 different N levels based on soil-testing recommendation rates (SR) of Standard Fertilizer Recommendation: 0.5, 0.75, 1.0 and 1.5 times of SR. Phosphate and potassium were applied as much as the SR by the guide. Strawberry plants were cultivated from Sep., 2017 to May, 2018 with the density of 1.0 × 0.1 m. The growth and NPK uptake rates were estimated every 30 days from 30 days after transplanting (DAT) until final harvest. The growth rates (as expressed dry weight) were not significantly different between N treatments throughout the whole growth period. Soil nitrate-N contents at the final harvest stage showed significant difference between treatments; 1.5 times was the greatest and the others were similar to each other as much as the contents before transplanting. In order to validate effects of the newly developed fertigation guide, the yield was compared to soil-testing based fertigation rates and farmer’s practice, and was not significantly differed between both practices. On the other hand, the nutrient use efficiency was the greatest in the developed fertigation guide for both N and P due to the reduced fertilizer application. It implies that the growth rates-based variable application is a key consideration to make the fertigation guide of various greenhouse crops for sustainable cultivation. The recommended fertigation guide by the growth stage-based on the NPK uptake at the reference productivity for greenhouse strawberry. Growth stage Week after transplanting Fertigation rates (g 10a-1) N P K Rooting and early growth 1 - 10 300 40 270 Harvesting (1st flowering) 11 - 16 550 60 450 Harvesting (2nd flowering) 17 - 24 350 60 350 Harvesting (3rd flowering) 25 - 35 400 70 500 Total 4,450 700 4,540 Urea, mono potassium phosphate, and potassium chloride were used fro the fertigation. - COLLAPSE
    August 2021
  • Article

    Soil Chemical Properties and Bush Growth of Two Blueberry Cultivars as Affected by Soil Media Mixed with Peatmoss and Cocopeat
    Mi Geon Cheon, Seo Hyoun Lee, Kyung Mi Park, Seong-Tae Choi, Yeon Hyeon Hwang, and Young Ho Chang
    This experiment was conducted to evaluate the usefullness of cocopeat as a soil medium in blueberry cultivation. Two-year-old northern highbush blueberry ‘Duke ... + READ MORE
    This experiment was conducted to evaluate the usefullness of cocopeat as a soil medium in blueberry cultivation. Two-year-old northern highbush blueberry ‘Duke’ and southern highbush blueberry ‘Spring High’ were planted in soil medium mixed with peatmoss (soil:peatmoss (v/v), 1:1) or cocopeat (soil:cocopeat (v/v), 1:1) in open fields in 2019. Soil pH measured in 2020 and 2021 ranged from 4.2 to 5.0 in peatmoss and 5.2 to 5.8 in cocopeat medium, indicating peatmoss has more suitable pH for blueberry growth. Two years soil analyses indicated that peatmoss medium tended to contain a higher available P2O5 content and lower exchangeable cations compared with those of cocopeat. In 2021, peatmoss medium significantly increased the number of shoots per bush, by 16% for ‘Duke’ and 92% for ‘Spring High’ compared with the cocopeat. Bushes from peatmoss medium produced yield 1.9- to 2.7-fold higher for two years in ‘Duke’ and 1.4- to 1.8-fold higher in ‘Spring High’ compared with respective yields from cocopeat. Fruit characteristics for two years were not consistently affected by different soil media, except that the acidity was slightly higher in peatmoss. The results suggested that since the better bush growth from peatmoss medium resulted mainly from lower soil pH, the use of cocopeat as a soil medium should be followed by pH adjustment. Yield and fruit characteristics of two blueberry cultivars as affected by different soil media. Year Cultivar Soil medium Yield (kg/bush) Fruit characteristic Berry weight (g) Soluble solids (°Brix) Titratable acidity (%) Firmness (N) 2020 Duke Peatmoss 0.97 2.2 10.5 0.35 4.9 Cocopeat 0.36 2.4 9.8 0.33 3.4 ** ns * ns ns Spring high Peatmoss 0.46 2.3 10.2 0.34 3.6 Cocopeat 0.34 2.3 10.0 0.34 3.1 * ns ns ns ns 2021 Duke Peatmoss 4.0 2.2 11.1 0.58 3.1 Cocopeat 2.1 2.4 10.1 0.38 3.1 * ns ns * ns Spring high Peatmoss 5.2 3.3 11.2 0.48 3.8 Cocopeat 2.9 3.2 11.0 0.36 2.7 ** ns ns ns * NS, *, ** Nonsignificant or significant at p ≤ 0.05, or 0.01, respectively. - COLLAPSE
    August 2021
  • Article

    Effects of Illite-Containing Fertilizer Prototype on Soil Chemical Property and Tomato Growth
    Young-Ran Lee, Hye-Sun Lee, Ga-Eun Kim, Young-Tae Shin, Jae-Yeon Joo, Jae-Joon Lee, and Jwakyung Sung
    Illite, a 2:1 clay mineral of silica-alumina-silica layer, includes high potassium (K) content. Despite of being used as a material in ... + READ MORE
    Illite, a 2:1 clay mineral of silica-alumina-silica layer, includes high potassium (K) content. Despite of being used as a material in various industries including agriculture, the relatively insufficient physico-chemical properties such as relatively low cation exchangeable capacity (CEC) limit its usage in agricultural practices. The aim of this study is to investigate effects of illite-containing prototypes on soil and tomato growth. To achieve these goals, we made two types of illite-containing prototype; prototype-A (illite- and microbes-containing product for soil amendment), and prototype-B (illite- and NPK-containing product for plant growth promotion). Four weeks-old tomato seedlings were transplanted into soils after 5 days of different treatments. At 60 days after treatment, soil and plant were harvested from each treatment, and used for further analysis. A prototype-A for soil amendment showed enhanced EC and exchangeable K (p < 0.05), and, interestingly, lowered soil pH. A prototype-B for plant growth promotion increased significantly photosynthesis, thereby enhancing growth rate (dry weight) and nutrient uptake (p < 0.05). Additionally, a prototype-B affected positively the levels of antioxidant activities in the leaves and fruits (p < 0.05). In this context, our observations suggest that illite-containing products could be possible for agricultural use, and, despite the findings, further study is strongly required to validate the effects of illite-containing products such as prototype-A and -B, and to find out unknown effects. Application effect of illite-containing prototype on soil chemical properties and tomato growth. - COLLAPSE
    August 2021
  • Article

    Comparative Uptake and Translocation of Thallium in Selected Plant Species Grown in Artificially Contaminated Soils
    Dong-Jin Kim, Byeong-Seok Kang, and Jin-Ho Lee
    Thallium (Tl) is a widely dispersed toxic element and remains in the environment. It is distributed in some soils near cement plants ... + READ MORE
    Thallium (Tl) is a widely dispersed toxic element and remains in the environment. It is distributed in some soils near cement plants, abandoned mines and smelter areas in Korea ranging from 0.18 to 12.91 mg Tl kg-1. In this study, we investigated the Tl uptake by the selected food crops, Cucumis sativus and Phaseolus vulgaris, from artificially Tl-contaminated acidic and neutral soils with or without the application of diethylene triamine pentaacetic acid (DTPA). The Tl concentrations in the plant tissues increased with increasing the soil Tl concentrations. The shoot Tl concentrations of plants ranged from <0.1 mg kg-1 to 102.7 mg kg-1. The root Tl concentrations were between 8.5 mg kg-1 and 685.8 mg kg-1. The Tl uptake by cucumber plant was always higher than by bean plant, and Tl in the plant tissues were much higher in the acidic soil than in the neutral soil. However, the correlations among the shoot and root Tl concentrations, Tl-bioaccumulation factor (BAF) values, and Tl-translocation index (TLI) values for bean plant were higher than for cucumber plant. When DTPA was applied to the soils, the Tl in the plant tissues generally increased. In addition, the DTPA application in neutral soil affected positively the Tl translocation in both the plants, but in the acidic soil, it influenced only in bean plant. Bioaccumulation factor and translocation index of thallium in cucumber and bean grown in the artificially Tl contaminated acidic soil. - COLLAPSE
    August 2021
  • Short Communication

    Dry Weight and Inorganic Nutrient Contents in Different Parts of Container-Grown Highbush Blueberry ‘Duke’ with or without Hydroponic Solution Supply
    Mi Geon Cheon, Seo Hyoun Lee, Kyung Mi Park, Seong-Tae Choi, Yeon Hyeon Hwang, and Young Ho Chang
    This experiment was conducted to understand nutrient uptake of container-grown highbush blueberries in plastic film house. In March 2013, one-year-old ‘Duke’ was ... + READ MORE
    This experiment was conducted to understand nutrient uptake of container-grown highbush blueberries in plastic film house. In March 2013, one-year-old ‘Duke’ was planted in a 180-L container mixed with peatmoss (130 L) and perlite (40 L), and hydroponic solution was supplied (fertilization) or not (non-fertilization) until October 2020. Hydroponic solution consisted of NO3-N 4.6, NH4-N 3.4, PO4-P 3.3, K 3, Ca 4.6, and Mg 2.2 mmol L-1 and the non-fertilization was supplied with only underground water. In October 2020, total dry weight of a blueberry increased 1.5-fold more in the fertilization than in the non-fertilization. Dry weight and inorganic nutrient content were the greatest in root than in leaf, shoot, old branch, and cane, indicating importance of root as a reserve storage organ. Fertilization increased dry weight by 2-fold and inorganic nutrient contents of root by 2.2 - 2.6-fold. Total content of each nutrient in a bush increased 1.8 - 2.2-fold more by the fertilization. In non-fertilized treatment, maintaining dry weight and nutrient contents for 8 years indicated that plants absorbed the nutrients to some extent through mineralization of peatmoss medium and underground water. Dry weight in different parts of 8-year-old blueberry bush as affected by fertilization treatment for 8 years. - COLLAPSE
    August 2021
  • Review Article

    Research Trends Using Soil Sensors for Precise Nutrient and Water Management in Soil for Smart Farm
    Han Na Kim and Jin Hee Park
    The imbalance of nutrient and water supply can negatively affect crop productivity and environment. Therefore, it is necessary to monitor nutrient and ... + READ MORE
    The imbalance of nutrient and water supply can negatively affect crop productivity and environment. Therefore, it is necessary to monitor nutrient and water status of soil and precision management of the soil is required. Soil water content can be measured using sensors such as frequency domain reflectometry (FDR) and time domain reflectometry (TDR). Tensiometer was commonly used to determine irrigation timing and amount to supply water. Organic matter in the soil can be measured using a near infrared spectrometer (NIR) sensor, which showed good correlation with soil organic matter contents. On-the-go pH sensor was used for pH mapping of soil with high resolution. Generally, organic matter and pH sensors are less used for soil based smart farm system than soil moisture sensors, but used for the characterization of soil. There are no available sensors to monitor nutrient levels in soil directly. To use ion selective electrodes, soil solution should be extracted. Instead, monitoring soil EC can be used to manage nutrients in soil since the soil EC is related to nutrients in soil solution. However, EC and nutrient availability in soil are affected by various factors such as soil water content, temperature and soil texture. Therefore, calibration of EC based on soil texture, CEC, soil organic matter, and etc. is required. Recent researches for soil based smart farm focused on wireless sensors, plant wearable sensors, and intelligent agriculture systems. Combined monitoring of environmental conditions and plant biometric information will achieve smart and precision agriculture. Various soil sensors to monitor soil water, temperature, pH, organic matter and EC. - COLLAPSE
    August 2021