• Article

    Revised Soil Survey of Chungju-Si in Chungchungbukdo
    Byung-Keun Hyun, Yeon-Kyu Sonn, Sang-Ho Jeon, Soon-Gang Yun, Hyun-Jun Cho, Sug-Jae Jung, Jung-Won Choi, and Dong-Sung Lee
    Agricultural lands have decreased continuously because of urbanization, land consolidation, road construction, etc. Especially, rapidly urbanizing areas such as Cheongju-si in South ... + READ MORE
    Agricultural lands have decreased continuously because of urbanization, land consolidation, road construction, etc. Especially, rapidly urbanizing areas such as Cheongju-si in South Korea has the severe land-use change. In this regard, Our study was aimed investigating land-use changes including soil properties and soil information to provide the basic soil information and soil management practices in the region. The area of crop cultivated land of South Korea in 2016 reduced by 35,424 ha compared to that of 2014. The paddy and upland field decreased by 12,455 and 22,969 ha respectively. The reasons for the decrease of the paddy field are as follows: converting the paddy field to upland (22,780 ha) > others (3,646) > public facilities (2,740) > building (2,642) > idle land (1,439). The reasons for the increase of the upland filed are as follows: switching paddy to upland (22,780 ha) > others(5,330) > reclamation of upland (1,415). The main reason converting paddy field to upland was cultivating more profitable upland crops or fruit trees. The arable land in Chungju-si had been reduced by 1,087 ha in 2014 since 1999. The ratio of the reduced arable land was about 48%. Our results showed that paddy fields located in alluvial plains were changed into upland or green house. In particular, paddy fields have been changed to not only upland, orchard, greenhouse cultivation but also fallow land. Moreover, our research using 3686 soil codes (soil phases) and 3834.2 ha indicated that the number of soil series and soil phase increased to 74 and 160 from 65 and 126 individually. The largest increased area was Sachon (coarse loamy fluvaquentic endoaquepts) soil series 536.3 ha which were modified from the existing Yecheon, Sanju, Wolgog, and Seongsan soil series. The various types of change of paddy field in Chungju-si. - COLLAPSE
    August 2018
  • Article

    Growth-inhibition Patterns and Bioconcentration Profiles in Cadmium-stressed Oilseed Rape (Brassica napus L.)
    Ha-il Jung, Myung-Suk Kong, Eun-Jin Lee, Goo-Bok Jung, and Yoo-Hak Kim
    Cadmium (Cd) uptake and accumulation from soil to plant vary depending on the environment conditions. Here, we studied the chemical properties of ... + READ MORE
    Cadmium (Cd) uptake and accumulation from soil to plant vary depending on the environment conditions. Here, we studied the chemical properties of Cd-treated soils, the growth-inhibition rates of Cd-exposed oilseed rape plants, the changes in Cd content of soil, and the relationship between Cd bioconcentration factor and Cd accumulation from the soil to oilseed rape organs. Oilseed rape plants were cultivated in a greenhouse under four Cd treatments: 0 (control), 4, 8, and 12 mg kg-1. A significant positive correlation was found between Cd concentration and available P2O5 or exchangeable K. The Cd concentration for 25% shoot growth inhibition (GR75) was 8 mg kg-1. Cd content in the root and shoot was positively correlated in the flowering stage of oilseed rape. Bioconcentration factor (BCF)root/soil decreased with Cd concentration and Cd accumulation in the 8 mg kg-1 treatment was higher at flowering stage. Cd accumulation was related to plant biomass and soil Cd concentration. We found that Cd accumulation would be much greater in Cd concentrations that allowed plant growth and development. Thus, a species-specific threshold concentration must be determined based on Cd phytotoxicity for phytoremediation of Cd-contaminated soils. Cd bioconcentration factors between soil and root or shoot (A) and Cd accumulations in roots and shoots of oilseed rape plants at flowering stage (B), and comparison of the bioconcentration factors between root and shoot tissues (figures at top of the columns). - COLLAPSE
    August 2018
  • Article

    Impact of Application of Slurry Composting-Biofiltration (SCB) Liquid Fertilizer on Yield of Red Pepper and Nitrogen Leaching
    Tae-Jun Lim, Jin-Myeon Park, and Seok-Beom Kang
    The objective of this study was to assess application effects of slurry composting bio-filtration liquid fertilizer (SCB) on red pepper (Capsicum annuum ... + READ MORE
    The objective of this study was to assess application effects of slurry composting bio-filtration liquid fertilizer (SCB) on red pepper (Capsicum annuum L.) yield and nitrate leaching. A lysimeter experiment was conducted to evaluate the impact on the nitrate leaching and red pepper yield No N fertilizer, four application N rates of SCB (0, 103, 155, and 206 kg ha-1) and a control treatment of chemical fertilizer (103 kg ha-1). SCB were used as a basal fertilization and three top dressing doses of urea at the 35th, 60th, and 80th day after transplanting were applied. There was no significant different in red pepper yield among the SCB 100%, 150%, 200%, and CF 100%, though which was decreased in the No N fertilizer in 2008 and the No N fertilizer and the SCB 0% in 2009. The Increase of SCB liquid fertilizer application rates intensified the leached nitrate concentration and nitrate load. The leached N load in the SCB 100% was 193 kg ha-1 in 2008 and 138 kg ha-1 in 2009. However the leached N load in the SCB 150% and 200% were 236 and 274 kg ha-1 in 2008 and 173 and 216 kg ha-1 in 2009, respectively which were higher 43 and 80 kg ha-1 in 2008 and 38 and 78 kg ha-1 compared to that in the SCB 100%. Meanwhile, the SCB 100% did not increased the nitrate leaching compared with the CF 100% though the leached N load was higher in the SCB 100% in early season of red pepper cultivation. Therefore, the application of SCB rates equivalent to N recommendation for red pepper was evaluated to substitute a basal nitrogen fertilizer because there was no difference in nitrate leaching and red pepper compared with the chemical fertilizer. Fruit yield of red pepper by chemical N fertilizer and different SCB liquid fertilizer treatments in 2008 and 2009. Treatment† Fruit yield of red pepper 2008-yr 2009-yr Average --------------------------- kg ha-1 --------------------------- No N fertilizer 12,170b‡ (919) ‡ 7,400c (358) 9,785 SCB 0% 14,460ab (1,068) 12,010b (533) 13,235 SCB 100% 16,390a (1,215) 17,760a (624) 17,075 SCB 150% 17,250a (1,287) 18,880a (942) 18,065 SCB 200% 15,940a (1,264) 16,820a (737) 16,380 CF 100% 16,180a (1,324) 18,530a (764) 17,355 †Different letters indicate significant difference (P< 0.05) within each fruit yield. ‡Values in parentheses denote the standard error. - COLLAPSE
    August 2018
  • Article

    Changes of Soil Organic Carbon in Forest and Arable Soil Under Different Altitude Levels
    Chang Hoon Lee, Seok-Cheol Kim, Myung-Sook Kim, Seong-Jin Park, Sun-Gang Yun, Yu-Hak Kim, and Taek-Keun Oh
    Soil organic carbon(SOC) is one of the most important constituents of soils due to its capacity in affecting plant growth indirectly and ... + READ MORE
    Soil organic carbon(SOC) is one of the most important constituents of soils due to its capacity in affecting plant growth indirectly and directly. The change of SOC content is associated with organic input with various sources in soil. This study was conducted as follows; the evaluation of the effects of altitude above sea levels on SOC concentration in forest and arable soil under climatic zone, investigation of relationship between SOC contents and temperature in soil with elevation. Under the different climatic zone, the SOC concentration in forest and arable soil was affected by increasing the altitude levels. The SOC concentration of forest soil was higher than that of arable soil regardless of climatic zone. Also, the SOC was dramatically related to the soil temperature with altitude, which was induced the increase of SOC contents in forest and arable soils. These results indicated that the soil temperature with altitude could be differed carbon storage in forest and arable soil between climatic zone. Effect of elevation gradient on soil organic carbon(SOC) in forest and arable soils under different climatic zone. - COLLAPSE
    August 2018
  • Article

    Estimation of Nitrogen Fertilizer Recommendations for cucumber by Soil Incorporation of Rye Based on Soil Nitrate Nitrogen Content
    Tae-Jun Lim, Jin-Myeon Park, and Seong-Eun Lee
    In this study, we estimated the appropriate nitrogen (N) recommendations of cucumber by evaluating the effects of soil incorporation of rye (Secale ... + READ MORE
    In this study, we estimated the appropriate nitrogen (N) recommendations of cucumber by evaluating the effects of soil incorporation of rye (Secale cereal L.) as a green manure crops on the growth and yield of cucumber under the greenhouse condition showing two different soil nitrate N levels. One, soil nitrate-N content before the experiment was 60 mg kg-1, carried out in 2012 and the other showing a 227 mg kg-1 level was conducted in 2013. Six different N treatments were used as follows: No N fertilizer, rye, rye with urea 0.5 N, 0.75 N, and 1.0 N, and urea 1.0 N. The amount of N supply from soil incorporation of rye was 146 kg ha-1 in 2012 and 107 kg ha-1 in 2013. When soil nitrate N content before the experiment was 60 mg kg-1, the growth and yield of cucumber did not differ between the rye + urea 0.5 N and the urea 1.0 N, which can reduce 50% of N fertilizer recommendation. In case of soil nitrate N content before the experiment was 227 mg kg-1 or beyond, no N fertilization can be recommended because there were no significant differences in the growth and yield of cucumber among all treatments including the rye. Lastly, when soil nitrate N content before the experiment was within range of 227 - 60 mg kg-1, N recommendations can be calculated through the equation Y = -3.34X + 227 (X: % of N recommendations, Y: soil nitrate N content). However, further studies on the relationship between soil nitrate N content and yield of cucumber are required. The estimation of reduction rates for Nitrogen fertilizer by soil incorporation of rye based on soil nitrate nitrogen content in cucumber. Soil NO3-N content Fertilization rates for N recommendations mg kg-1 % > 227 No fertilization 227 - 60 Y = -3.34X + 225† 60 50% of N recommendations †X: Percent of N recommendations, %; Y: Soil NO3-N content, mg kg-1. - COLLAPSE
    August 2018
  • Article

    A Study of the Urban Garden Soil Health in Busan Area
    Jin-Suk Kwag, Eun-Jeong Cho, Mi-Eun Jeong, Kwang-Yong Ju, Dae-Young Jeon, and Hui-Cheol Jeong
    The study of urban agriculture is focused on conceptual, active and policy establishment, and studies on the health of the vegetable gardens ... + READ MORE
    The study of urban agriculture is focused on conceptual, active and policy establishment, and studies on the health of the vegetable gardens are minimal. This study analyzed the chemical properties of urban vegetable soils. The area of 29 urban vegetable gardens in the Busan area was divided into suburban area and urban areas. In the urban areas, the soil of the vegetable garden was high in content of organic matter and exchangeable cations and it is believed that there is more fertilizer in urban areas. The average value and range of soil fertility items were 6.87 (5.64~8.04) for pH, 43.4 g kg-1 (6.6~88.3) for organic matters, 845.3 mg kg-1 (115.9~2758.1) for available phosphate, 1.30 cmol kg-1 (0.23~3.66) for K+, 17.27 cmol kg-1 (6.05~46.50) for Ca2+, 2.88 cmol kg-1 (0.94~3.49) for Mg2+, and 2.66 dS m-1 (0.53~10.40) for electrical conductivity. Location map of the target area of the study. - COLLAPSE
    August 2018
  • Article

    Effect of Fertilizers Using Ferro-Nickel Slag on Chinese Cabbage Growth and Soil Chemical Properties
    Jin-Ju Yun, Byung-Hwa Kang, Se-Won Kang, Sang-Yoon Kim, Dong-Cheol Seo, and Ju-Sik Cho
    This study was conducted to investigate the application effect of fertilizer using ferro-nickel slag on Chinese cabbage cultivations in upland field. Field ... + READ MORE
    This study was conducted to investigate the application effect of fertilizer using ferro-nickel slag on Chinese cabbage cultivations in upland field. Field experiments were designed with control (Cn), ferronickel slag soil conditioner fertilizer (FNS SCF), ferronickel magnesium fertilizer (FNS MGF), and conventional silicate fertilizer (CSF) treatments. Chinese cabbage fresh weight, length, leaf width, and leaf number during the harvest period showed high growth at the FNS SCF and FNS MGF treatment area. Compared to the control group, the FNS SCF and CSF treatment areas showed 26% heavier fresh weight. During the harvest period, compared to the growing period, the contend of inorganic components in Chinese cabbage seemed to decrease, but Na2O was increasing in the root. The T-N showed pretty high in the outer leaf at the CSF and FNS MGF treatment areas. Heavy metal content of Chinese cabbage during the harvest period, compared to the growth period, showed overall decrease. During the harvest, the Ni content in the outer leaf showed highest at FNS MGF, in the inner leaf highest at Cn treatment area, and in the root highest at the FNS SCF treatment area. Growth properties of Chinese cabbage in harvest period. Treatment† Fresh weight (g plant-1) Head width Head height Head tightness Plant weight Head weight (cm) (cm) Cn 3.92a‡ 2.41a 17.0a 27.6ab 10.73a FNS SCF 4.88b 3.12b 18.7b 28.9b 13.00b CSF 4.94b 3.10b 18.7b 28.4ab 12.97b FNS MGF 4.33ab 2.73ab 18.0ab 26.8a 11.95ab †Cn, control; FNS SCF, ferronickel slag soil conditioner fertilizer; CSF, conventional silicate fertilizer; FNS MGF, ferronickel magnesium fertilizer. - COLLAPSE
    August 2018
  • Article

    Impacts of Different Amounts of N, P, and K Fertilizer Applications on Growth of Cirsium japonicum var. ussuriense Related to Soil Properties
    Byung-Koo Ahn, Do-Young Ko, Hyo-Jin Kim, Min-Sil Ahn, Jin-Ho Lee, and Yee-Jin Lee
    Cirsium japonicum var. ussuriense is a perennial herb grown widely in Korea and also known as Korean thistle which is used in ... + READ MORE
    Cirsium japonicum var. ussuriense is a perennial herb grown widely in Korea and also known as Korean thistle which is used in oriental medicine with various pharmacologic effects. This study was conducted to investigate the growth of Korean thistle and the changes of soil chemical properties in the thistle fields as influenced by different application levels of nitrogen (N), phosphorus (P), and potassium (K) fertilizers as N, P2O5, and K2O, and to determine the optimal application levels of N, P, and K fertilizers for cultivating the Korean thistle. The N, P, and K fertilizers were applied as 0 (0%), 0.5 (50%), 1.0 (100%), 1.5 (150%), and 2.0 (200%) times based on the level of N, P, and K treatments (N-P2O5-K2O = 61-70-72 kg ha-1) for conventional thistle cultivation. Selected chemical properties of soils at harvesting stage of the plant as compared to those before transplanting the plant were as follows: soil pH value and available P concentration decreased. Electrical conductivity (EC) value and N concentration increased with increasing the amounts of P application , but soil organic matter (SOM) content was not changed. In particular, the concentrations of exchangeable Mg were proportionally increased with increasing N applications. The plant uptake of N increased up to 100% of the N application level, but it decreased with over 150% of the N treatment level. On the other hand, P and K uptake increased up to 100% of the P and K application levels, but the K uptake was not changed with over 150% of the K level. Based on productivity of the plant aerial part, we suggest that the optimal rates of N, P, and K fertilizer applications would be as N-P2O5-K2O = 87-52-81 kg ha-1. In addition, the concentrations of selected phytochemicals in the plant were also changed with the different fertilizations. Total flavonoid concentration in the plant was highest at 50% of the N application level and control K level. Total polyphenol concentration was highest at 50% of the N level and lowest at 200% of the K treatment level. Relationship between yields of Cirsium japonicum var. ussuriense and application levels of N, P, and K fertilizers. - COLLAPSE
    August 2018
  • Article

    Design of the Spatial Sampling Scheme for Estimating the Cultivation Area of Garlic and Onion Using Satellite-Based and Unmanned Aerial Vehicle Remotely Sensed Data
    Di Wang, Kyung-do Lee, Zhong-xin Chen, Sangil Na, Chan-won Park, and Kyu-ho So
    Garlic and onion are the most important vegetable crops in Korea. The accurate estimation of cultivation area for garlic and onion acreage ... + READ MORE
    Garlic and onion are the most important vegetable crops in Korea. The accurate estimation of cultivation area for garlic and onion acreage is critical to predict the production of vegetable crops, adjust agricultural planting plan and ensure an effective supply of farm products. However, the plots cultivated with garlic and onion are very fragmentary and dispersive because the cross cropping commonly occurs in the two crops. Therefore, it is very difficult to establish the accurate identification of garlic and onion using satellite-based remotely sensed images alone. In case of tracking Hapcheon Gun, Korea as the sampling site, objective of this study was to formulate a spatial sampling scheme through combining satellite-based, unmanned aerial vehicle (UAV) remotely sensed images and the stratified sampling method for improving the estimated accuracy to cultivation area of garlic and onion. The results are shown that there was almost no classification error, when UAV remotely sensed image was used to retrieve the cultivation area of garlic and onion. The error found in the two crops classification using Rapid Eye satellite-based images, and the classification error for garlic was the larger than that of onion;. The variance for cultivation area of garlic and onion within each stratum can be significantly decreased, when the proportion of the cultivation area for two crops is accounted for one sampling unit. It was observed that the required sample size for meeting the designed extrapolation accuracy decreased with the stratification number of the sampled population. Comprehensively considering population extrapolating accuracy, sampling survey cost and rationality, 10 strata was the optimum stratification number. It was appeared that the spatial stratified sampling scheme combining satellite-based and UAV remotely sensed images had a high accuracy and stability for estimation of cultivation areas for the two crops, because both the relative error and CV of population extrapolation using this scheme was less than 10%. Results of population extrapolation and error estimation for garlic acreage in the study area in 2017. Stratum number Nh N Wh nh fh (%) (m2) sh2 1 198 422 0.4692 28 0.1414 10272.57 111059383.60 2 78 422 0.1848 10 0.1282 23347.15 441781199.13 3 47 422 0.1114 6 0.1277 53480.35 217588913.35 4 41 422 0.0972 5 0.1220 72042.97 598687783.10 5 24 422 0.0569 3 0.1250 101778.39 85000902.09 6 17 422 0.0403 3 0.1765 116648.67 1006782408.64 7 7 422 0.0166 2 0.2857 143419.00 765673525.59 8 4 422 0.0095 2 0.5000 144819.77 2796755176.20 9 3 422 0.0071 2 0.6667 269129.69 10129222962.02 10 3 422 0.0071 2 0.6667 261057.10 1065556621.53 r (%) 7.22 CV (%) 5.12 - COLLAPSE
    August 2018
  • Short Communication

    Changes of Exchangeable K in Paddy Soil Applied Potassium Fertilizer for 62 Years
    Myung-Sook Kim, Suk-Chul Kim, Seong-Jin Park, and Chang-Hoon Lee
    Potassium (K) is a main macronutrient for rice but deficit of potassium can have an effect on the productivity of rice and ... + READ MORE
    Potassium (K) is a main macronutrient for rice but deficit of potassium can have an effect on the productivity of rice and sustainability of paddy soil fertility. In an experiment conducted at the long-term research field of the National Institute of Agricultural Science, we investigated the effects of mineral fertilizer and rice straw compost on dynamic and balance of potassium under a rice single system. The treatments were no fertilization (No fert.), inorganic fertilization (N, NPK), and inorganic fertilizer plus rice straw compost (NPKC). The concentrations of exchangeable K in all treatments were ranged from 0.08 to 0.23 cmolc kg-1 with fluctuation by a 10-year cycle. Especially, exchangeable potassium in NPKC treatment was higher 0.05~0.19 cmolc kg-1 than that of No fert. treatment. K balance in all treatments resulted in the negative level that ranged from –3.4 to –36.4 cmolc kg-1. These were attributed to supply from K minerals of soil that were identified muscovite, biotite, microcline, and anorthoclase. Changes of Exchangeable K by applying of potassium fertilizer and rice straw compost from 1968 to 2015. No fert., N, P, K, C, L, and S mean no fertilization, nitrogen, phosphate, potassium, rice straw compost, lime, and silicate fertilizer, respectively. - COLLAPSE
    August 2018
  • Article

    Effect of Curing Treatments on the Fusarium Wilt (Fusarium oxysporum) of Sweet Potato (Ipomoea batatas L.)
    Jin-Young Moon, Byeong-Kyu Min, Jung-Ho Shin, Yong-Cho Choi, Hyeon-Ji Cho, Young-Han Lee, Jeongyeo Lee, and Jae-Young Heo
    Fusarium wilt (Fusarium oxysporum) is responsible for damage or negative effect on sweet potato (Ipomoea batatas L.) cultivation. This study evaluated the ... + READ MORE
    Fusarium wilt (Fusarium oxysporum) is responsible for damage or negative effect on sweet potato (Ipomoea batatas L.) cultivation. This study evaluated the effect of curing treatment on the growth of sweet potato and soil microbial communities using fatty acid methyl ester method. We utilized three treatment groups, control, curing treatment of cutting for a day (C1), and curing treatment of cutting for 5 days (C5). Soil chemical properties showed no significant effect for the treatments. The marketable root number per plant and yield of sweet potato in C5 treatment were significantly higher than those in control and C1 (p < 0.05), whereas the Fusarium wilt in C5 treatment showed significantly lower than that of the control and C1 (p < 0.05). In addition, Fusarium wilt showed significantly increase as increasing soil fungi biomass, while the yield of sweet potato significantly decreased as increasing Fusarium wilt (p < 0.05). The soil of C1 and C5 had a significantly lower biomass and community of fungi when compared with that of control (p < 0.05). These results indicate that curing treatment of cutting was more effect on the prevention of Fusarium wilt as well as the productivity of sweet potato. Correlation between soil fungal biomass, fusarium wilt and yield of sweet potato. - COLLAPSE
    August 2018
  • Article

    Nitrogen Availability Strongly Affects Productivity of Ratoon Rice Plants
    Hyeon-Kyoung Min, Seo-Ho Shin, Oh-Do Kwon, Woo-Jung Choi, and Han-Yong Ki
    Warming trends and concomitant increases in frost-free period are expected to alter cropping systems and subsequent land productivity in temperate climate regions. ... + READ MORE
    Warming trends and concomitant increases in frost-free period are expected to alter cropping systems and subsequent land productivity in temperate climate regions. Our agricultural and food systems need to adapt to such changes. Here, we examined how nitrogen (N) availability would affect productivity of rice double cropping in combination with its ratoon regenerated from their parents rice plant (Oryza sativa, cv. Jomyeong) with early maturing habit. For main cropping season, rice plants were transplanted in experimental paddy field (35°10'N, 26o53'E, alt. 33.0m) of Chonnam National University, on April 25, 2016, and grown under local farmers’ agronomic practices. After main crops harvested on August 17, ratoon rice plants were grown at five different levels of N availability [0 (N0), 9 (N9), 18 (N18), 28 (N28) and 37 (N37) kg N ha-1] and harvested on November 20. Unexpectedly, plant height of ratoon rice was unaffected by N availability. However, aboveground biomass (AGB) and yield of ratoon rice were significantly affected by N availability, displaying an increase of 56.5 kg ha-1 and 26.3 kg ha-1 per unit (1 kg ha-1) increase in N fertilization, respectively. As a result, while at N0, the AGB and yield of ratoon rice plants were 4.14 Mg ha-1 and 1.46 Mg ha-1, respectively, they increased to 6.32 and 2.35 Mg ha-1 at N37, corresponding to 47% and 41% of those (i.e. 13.39 Mg ha-1 in AGB and 5.68 Mg ha-1 in yield) of main rice plants. Under high N availability, the greater number of regenerated tillers and panicle per m2 contributed to greater ratoon rice productivity. Combined annual productivity of the main and ratoon seasons ranged from 17.5 to 19.7 Mg ha-1 for AGB and from 7.1 to 8.0 Mg ha-1 for yield depending on N availability. The results suggest that ratoon rice double cropping could provide an ample opportunity to consolidate national food security in the warming world by increasing annual land productivity. Field landscape of ratoon rice at harvest stage. - COLLAPSE
    August 2018
  • Article

    Changes in Chemical Properties of Greenhouse Soils Collected from Gyeongnam Province between 2000 and 2016
    Hyeon-Ji Cho, Daniel Son, Si-Lim Choi, Young Han Lee, Jeongyeo Lee, and Jae-Young Heo
    Long-term monitoring of soil chemical properties is the main agricultural practices to improve crop yield and soil fertility. Field monitoring was performed ... + READ MORE
    Long-term monitoring of soil chemical properties is the main agricultural practices to improve crop yield and soil fertility. Field monitoring was performed to evaluate the chemical properties of 200 greenhouse soil samples every 4 years from 2000 to 2016 in Gyeongnam province, South Korea. Soil properties such as pH, electrical conductivity (EC), amount of organic matter (OM), available phosphate (P2O5), nitrate nitrogen (NO3-N), exchangeable potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) were analyzed. In 2016, the average concentration of soils under greenhouse condition showed 6.8 for pH, 3.52 dS m-1 for EC, 40 g kg-1 for OM, 1,065 mg kg-1 for P2O5, 154 mg kg-1 for NO3-N, 2.35 cmolc kg-1 for K, 12.8 cmolc kg-1 for Ca, 4.0 cmolc kg-1 for Mg, and 0.91 cmolc kg-1for Na. In addition, the average concentrations of OM, K, Ca, and Na have tended to increase with year. In 2016, the frequency distribution of excessive level of soils under greenhouse condition was 43% for pH, 61% for OM, 94% for P2O5, 89% for K, 96% for Ca, and 83% for Mg. Soil EC values of green pepper, tomato, and lettuce were significantly higher than those of carrot, strawberry, and squash (p < 0.05), whereas soil pH was significantly lower in the carrot and lettuce than that in the strawberry (p < 0.05). Soil pH was significantly correlated with the EC, NO3-N, K, Ca, Mg, and Na. The value of EC was also positively correlated with the OM, P2O5, NO3-N, K, Ca, Mg, and Na. In conclusion, the long-term information on soil chemical properties will be helpful to improve sustainable soil and nutrient management for greenhouse farming. Frequency distribution of chemical properties in greenhouse soils of Gyeongnam Province (n = 200). - COLLAPSE
    August 2018
  • Article

    Morphological and Fractal Characteristics of Sesame (Sesamum indicum L.) Roots from Various Soil Moisture Contents
    Hyen Chung Chun, Amar Margaux, Romain Michel Gloaguen, Yu-Chien Tseng, Sanghun Lee, Ki-Yuol Jung, YoungDae Choi, and Diane Rowland
    Recently Korea has severe drought during sowing and early vegetative period of sesame cultivation. Sesame is an important oilseed crop in Korea, ... + READ MORE
    Recently Korea has severe drought during sowing and early vegetative period of sesame cultivation. Sesame is an important oilseed crop in Korea, so it is important to understand adaptation of sesame to water stress. This study investigated changes of morphological properties and spatial distribution of sesame roots under different soil moisture contents. The experiment was performed at University of Florida in Gainsville, USA. Two sesame cultivars (Bene and Indie) were planted in a test tube with 35 in length, 21 in width, and 4 cm in depth and grew for 23 days. The tubes were filled with turface soil with four soil moisture treatments (40, 50, 75 and 100%). The root images were obtained every 2 days using a scanner. Root properties from the images were characterized by root length, surface area, volume, number of roots and fractal parameters (fractal dimension and lacunarity). The results of this study showed that the all of root properties had no significant difference between cultures, but there was difference across soil moisture contents. The total length, surface area, volumes and number of roots increased as soil moisture increased from both cultivars. The values of fractal dimension increased as soil moisture increased, while the ones of lacunarity decreased. These results indicated that greater soil moisture induced more abundant and heterogeneous root structure. Correlation analysis among morphological properties and fractal parameters resulted in that the fractal dimension had the greatest correlation with number of roots. This result indicates that fractal dimension is strongly related to branching of roots. Sesame roots from soil moisture of 40 and 50% did not develop enough to have fractal root structure. Sesame roots are sensitive to soil moisture content in germination and early vegetative stage and they require soil moisture close to 100% to develop full root structure. These results would be useful to understand sesame responses to water stress and to manage irrigation amounts in sesame cultivation. Sesame (Bene and Indie) root images from four soil moisture treatments: a-40%, b-50%, c-75% and d-100% soil moisture content. - COLLAPSE
    August 2018
  • Article

    Assessment of Heavy Metal Concentrations in the Upland Soils of Gyeongnam Province
    Hyeon-Ji Cho, Daniel Son, Si-Lim Choi, Young Han Lee, Jeongyeo Lee, and Jae-Young Heo
    The management of heavy metals concentration in upland soil is important for a better understanding of the negative effects on the agroecosystem ... + READ MORE
    The management of heavy metals concentration in upland soil is important for a better understanding of the negative effects on the agroecosystem as well as on humans. The accumulation of heavy metals in upland soils is related to various factors, such as parent materials, topography, and soil physicochemical properties. In this study, we investigated the concentrations of 9 heavy metals (Cd, Cu, Ni, Pb, Zn, As, Cr, Cr6+, and Hg) and their relationships to environmental features of 176 upland soil samples collected from Gyeongnam Province, South Korea. Our results showed that soil pH was positively associated with the concentrations of Cd, Cu, and Zn in upland soils. Soil organic matter was also positively correlated with the concentrations of Cu, Pb, Zn, Cr6+, and Hg in upland soils. Depending on the type of crop, the concentrations of Cd, Cu, and As were highest in the soil of Chinese cabbage, while the concentrations of Pb and Zn were highest in the soil of Welsh onion. The clay contents in upland soils had a significant positive effect on the concentrations of Cu, Ni, As, and Cr. Also, the concentrations of Cd, Cu, and Zn were significantly high in fluviomarine plain, whereas those of Ni, As, and Cr were significantly high in diluvial terrace. These results showed that heavy metal concentrations in upland soils are regulated by soil physicochemical properties such as soil organic matter and clay content. Correlation coefficient between heavy metals and soil organic matter of upland soils in Gyeongnam Province (n =176).   OM Cd Cu Ni Pb Zn As Cr Cr6+ Hg pH 0.142 0.176*† 0.308*** 0.010 0.084 0.180* 0.085 0.032 -0.010 -0.002 OM   0.100 0.353*** 0.037 0.166* 0.352*** 0.130 0.138 0.299*** 0.175* Cd     0.404*** 0.062 0.332*** 0.408*** 0.433*** 0.056 -0.017 0.012 Cu       0.236** 0.458*** 0.713*** 0.310*** 0.181* 0.069 0.119 Ni         0.035 0.112 0.313*** 0.682*** -0.052 0.000 Pb           0.615*** 0.276*** 0.063 -0.079 0.170 Zn             0.248*** 0.109 0.066 0.125 As               0.174* 0.075 0.052 Cr                 -0.043 -0.006 Cr6+                   0.044 †P< 0.05; **P< 0.01; ***P< 0.001. - COLLAPSE
    August 2018
  • Article

    Estimation of Optimum Organic Fertilizer Application under Fertilizer Recommendation System
    Seok cheol Kim, Byong Gu Ko, Seong Jin Park, Myung Sook Kim, Seong Heon Kim, and Chang Hoon Lee
    Organic fertilizer has been one of soil management to improve crop productivity and soil fertility. Unfortunately, there is little information on optimum ... + READ MORE
    Organic fertilizer has been one of soil management to improve crop productivity and soil fertility. Unfortunately, there is little information on optimum level of organic fertilizer for crop cultivation. In this study, we were tried to use the fertilizer recommendation system for determining organic fertilizer application under upland soil condition. This work was carried out; 1) to compare the effects of organic fertilizer and compost application on yields of Chinese cabbage, and 2) to estimate optimum levels on three types of organic fertilizer of 0, 50, 100, 200, and 400% with 320 kg N ha-1. The yield of Chinese cabbage in organic fertilizer plots was ranged from 71.3 to 74.1% compared to yield index of NPK. which was 2-7 times higher than in compost treatments due to improvement of N uptake efficiency. However, organic fertilizer was required addition of about 1.5-2.0 times amount to the 4 Mg ha-1 to gain the same yield of NPK treatment, these was similar soil properties of NPK treatments. This result indicated that fertilizer recommendation system could be alternative to calculate optimum levels of organic fertilizer for crop cultivation in upland soil. Investigation of optimum application rate by organic fertilizers types. - COLLAPSE
    August 2018
  • Article

    Comparison of Different Approaches on Determining Nitrogen Balance in a Lowland Paddy Soil
    Hyun-Hwoi Ku
    Nitrogen (N) balance is a key indicator assessing a degree of soil fertility and N loading by accounting input minus output N ... + READ MORE
    Nitrogen (N) balance is a key indicator assessing a degree of soil fertility and N loading by accounting input minus output N in agro-ecosystem. However, a recent approach on determining N balance has been evaluated regarding a change in soil N stock for continuing crop cultivation. To describe an assessment method on N balance, this study was conducted with three different methods, Method A (Input N−Output N (crop N removal+Loss N) = N surplus or deficit), Method B (Input N − Output N (crop N removal+Loss N + Δ soil total N) = N surplus or deficit), and Method C (Input N − Output N (crop N removal+Loss N) + Δ soil total N = N surplus or deficit). Four levels (0, 60, 120, and 180 kg N ha-1) of N from urea and two levels (120 and 180 kg ha-1) of N from combination of urea and CM (Urea:Cattle Manure = 60:60 and 60:120) were applied in a lowland paddy soil. Results showed that Method B indicated all negative N values regardless the sources and rates of N application, while Method A and C described different N balance values in the given N applications. Using Method A, a response of N balance to urea applications (0, 60, 120, and 180 kg N ha-1) was linearly increased. The values of N balance were negative at 0 and 60 kg N ha-1, while it was close to zero at 120 kg N ha-1 and showed the higher value at 180 kg N ha-1, respectively. Similarly, the combined N applications at 120 and 180 kg N ha-1 showed similar N balance values. Meanwhile, Method C indicated different N balance values at the combined N applications, showing significantly higher N balance values at 120 kg N ha-1 and the more value at 180 kg N ha-1, as compared with Method A. The difference was attributed to the soil N stock considering as count factor in determination of N balance. Thus, the study recommended Method C when evaluating both of soil fertility and N loading in crop cultivation field. A response of N balance to urea applications (0, 60, 120, and 180 kg N ha-1) was linearly increased using Method A and C. However, the difference values of N balance between the method A and C in the combined N applications (Urea+CM 120 and 180 kg N ha-1) were attributed to the change of soil N as considering independent factor for method C. - COLLAPSE
    August 2018