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Original research article
- Growing spinach (Spinacia oleracea L.) organically in greenhouses can reduce greenhouse gas emissions
- Bomi Kim, Chang-Hee Lee, Deok-Hoon Yoon
- With the South Korean government announcing its carbon neutrality policy for 2050, greenhouse gas reduction and soil conservation in agriculture are being …
- With the South Korean government announcing its carbon neutrality policy for 2050, greenhouse gas reduction and soil conservation in agriculture are being emphasized. Greenhouse cultivation is rapidly developing for vegetable production and pest control, and is expected to increase further to prevent disasters such as extreme weather events caused by global warming. In this study, we investigated the differences in soil carbon stocks and global warming potential (GWP) between greenhouse cultivation methods. We divided spinach cultivation into organic (OF) and conventional (CF) farming. The GWP of OF was 14.2 tons CO2-eq. ha-1, which was 70% level of CF’s 20.3 tons CO2-eq. ha-1. Soil organic carbon storage (SOCS) was 27.39 ton C ha-1 for CF and 19.89 ton C ha-1 for OF, with OF accounting for 72.6% of the SOCS in CF, but not statistically significant. When SOC was analyzed by water-extractable carbon and hot-water extractable carbon, there were no significant differences between treatments, but the humic acid / fulvic acid ratio was 2.2 times higher in OF, humification ratio was 93.71% in OF and 96.82% in CF, and the soil microbial content was higher in OF. Although the results of this study are limited by the analysis after one season of spinach cultivation in a greenhouse, it is expected that organic farming can increase soil organic carbon storage and reduce greenhouse gas emissions in long-term experiments. The total global warming potential (GWP) of the organic farming (OF) was 30% lower than the conventional farming (CF) on greenhouse cultivation. - COLLAPSE
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Original research article
- Yield and nutrient use efficiency of sorghum-sudangrass hybrid plant under different NPK fertilization rates
- Bomin Seo, Jwakyung Sung
- Nutrient use efficiency (NUE) is widely recognized as an important indicator to evaluate the availability (uptake, utilization and recovery) of mineral nutrients. …
- Nutrient use efficiency (NUE) is widely recognized as an important indicator to evaluate the availability (uptake, utilization and recovery) of mineral nutrients. Sorghum-sudangrass hybrid tends to increase in cultivation scale due to vigorous growth and higher yield. Therefore, the aim of this study was to provide the optimal NPK fertilization rates for sorghum-sudangrass hybrid based on nutrient use efficiency and yield. The fertilization rates of N, P2O5 or K2O were divided into four levels; 0%, 50%, 100% and 200%. Biomass yield of sorghum-sudangrass hybrid at harvesting stage showed an increasing trend with fertilization levels but was not significantly within treatment groups. Uptake of N or K was significantly increase by fertilization levels of N or K2O, whereas P uptake was similar in all P2O5 fertilization levels. NUE was significant in N treatments, whereas P- and K-use efficiency did not differ significantly among different fertilization rates. Consequently, this study suggests that the recommended rates of N (175 kg ha-1), P2O5 (150 kg ha-1), and K2O (150 kg ha-1) were optimal for ensuring biomass production and nutrient use efficiency in the sorghum-sudangrass hybrid. IE (Interneal utilization efficiency, Y/U), PFE (Partial factor efficiency, Y/F). Y (yield, kg ha-1), U (nutrient uptake, kg ha-1), F (fertilization, kg ha-1). IE and PFE affected by different levels of N, P2O5 or K2O fertilization. - COLLAPSE
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Original research article
- Increased N2O emissions from aerobic soil with warming is mainly attributable to increased mineralization of organic nitrogen: An incubation study
- Min-Hyo Lim, Kyeong-Su Choi, Seok-In Yun
- Nitrous oxide (N2O) can be produced via microbial oxidation of ammonia (nitrification) in the aerobic soil. Warming, a factor influencing …
- Nitrous oxide (N2O) can be produced via microbial oxidation of ammonia (nitrification) in the aerobic soil. Warming, a factor influencing microbial activity, can increase the rates of ammonia oxidation and N2O emissions. However, the amount of ammonia, a substrate of nitrification process, is a critical factor in determining the cumulative N2O emissions from agricultural fields receiving nitrogen (N) fertilizer. To investigate the effects of increasing temperature on temporal variation and cumulative amount of N2O emissions in aerobic soil, we conducted an incubation experiment with soil treated with ammonium sulfate at 15 and 25°C. To maintain soil aeration, the soil water content during the incubation period was adjusted to the field capacity, and the concentrations of inorganic soil N (NH4+-N and NO3--N) and N2O emissions were periodically measured. During the incubation period, the sum of inorganic soil N increased due to the mineralization of organic N. The net increase in NO3- concentration, a product of ammonia oxidation, was 6% higher at 25°C than at 15°C, reflecting the increase in nitrification process following the increased mineralization of organic N. Nitrous oxide was mainly emitted during periods when sufficient NH4+ was present in soil, reflecting that ammonia oxidation was the main process of N2O production. Accumulated N2O emissions were 10% higher at 25°C than at 15°C, but the difference was statistically insignificant (P > 0.05). Despite the small and insignificant difference in accumulated N2O emissions between 15 and 25°C, 60% of the difference is attributable to the increase in the nitrification reaction. The results of this study suggest that N2O emissions may increase due to increased temperature in soil fertilized with N, but this increase is mainly attributable to increased mineralization of organic N and subsequent increased nitrification. Increased N2O emissions from aerobic soil with warming is attributable to increased mineralization of organic nitrogen and subsequent increased nitrification. - COLLAPSE
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Original research article
- Carbon and nitrogen metabolisms in rice growing with different levels of nitrogen fertilization under alkaline soil
- Gahyun Kim, Young-Tae Shin, Ga-Eun Kim, Jae-Yeon Joo, Jwakyung Sung
- A salt-affected alkali stress disrupts ion balance via water stress in plants, resulting in a malfunction of nutrient availability and physiological metabolism, …
- A salt-affected alkali stress disrupts ion balance via water stress in plants, resulting in a malfunction of nutrient availability and physiological metabolism, and this trend is dominant in alkali soils possessing lower nutrient levels. This study aimed to investigate how an adjustment of nitrogen fertilization rates affects rice growth and carbon and nitrogen metabolisms. To achieve this goal, three levels of nitrogen fertilization, 0, 75 and 15 kg ha-1, were incorporated into high pH soil (pH 9.2), and subsequent cultivation was followed by RDA manual. Leaves and roots from rice plants (cv. Asemi, alkali-tolerant) were harvested at tillering and heading stages. An increase in N fertilization did not promote growth, biomass production and N uptake. Alkali condition resulted in an accumulation of soluble sugar and starch in 0 kgN-fed roots, whereas 150 kgN showed reduced starch in leaves and roots. N deficit (0 kgN) up-regulated OsNADH-GOGAT in the roots, meanwhile high N (150 kgN) stimulated up-regulation of OsGS1;2. This study concluded that an adjustment of N fertilization rates was not effective in terms of growth and primary metabolism in low nutrients-containing alkali soils. Accordingly, we propose that subsequent study is required to examine the effect of N fertilization with diverse nutrients-containing alkali soils. Correlation coefficient among parameters involved in carbon and nitrogen metabolisms in the leaves (left) and roots (right) of rice plant. - COLLAPSE
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Original research article
- Determination of sowing dates for hairy vetch (Vicia villosa) and rye (Secale cereale) cultivation in Korea north region
- Yeon-Ho Kim, Cho-Rong Lee, Hyun-Young Hwang, Nan-Hee An, Jeong-Ah Jeong, So-Hui Kim, Sang-Min Lee
- Crop productivity in North Korea’s farmland is low due to cold climate and low soil fertility. Green manure is strongly recommended to …
- Crop productivity in North Korea’s farmland is low due to cold climate and low soil fertility. Green manure is strongly recommended to improve soil fertility and crop yield as an alternative to chemical fertilizer. However, the optimum sowing date of green manure under North conditions has not been investigated yet. Therefore the objective of this study was to select the sowing date for Hairy vetch and rye considering North Korea’s climate conditions. The sowing period consisted of 6 times autumn sowing, three times winter sowing, and one time spring sowing. Average minimum temperature (°C), germination rate (%), over wintering survival rate (%), and plant height (cm) were surveyed. Dry matter weight (kg ha-1) and nutrient input (kg ha-1) were also analyzed. The soil temperature at the experimental site, located near North Korea, was 5°C lower on the average temperature during the cultivation period compared to the central region of South Korea. According to the growth survey and production analysis, it was appropriate to sow hairy vetch and rye no later than September 27th and October 7th, respectively. Late sowing was negatively impacted by low temperatures, resulting in reduced crop growth and nutrients production. Considering climate conditions, selecting a proper sowing date could be a useful agricultural practice for maximizing green manure biomass. Correlation between green manure biomass (dry weight) and the average minimum temperature during the first month after sowing (p < 0.05). - COLLAPSE
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Original research article
- Effect of the combined treatment of red mud and gypsum on plant-available arsenic in acidic and alkaline soils
- Mina Lee, Chaw su Lwin, Namhee Yi, Taehee Baek, Jinhwan Park, Kwon-Rae Kim
- Red mud (RM) is noted for its ability to immobilize heavy metals by absorbing and precipitating them. However, RM's high alkalinity increases …
- Red mud (RM) is noted for its ability to immobilize heavy metals by absorbing and precipitating them. However, RM's high alkalinity increases soil dissolved organic carbon (DOC), which hinders the absorption of anionic metals like arsenic (As), thereby reducing its immobilization effectiveness. Conversely, phosphogypsum (G) lowers soil pH and DOC levels. Thus, combining RM and G is proposed to enhance immobilization efficiency. This study examined their combined impact on heavy metal(loid) immobilization in 39 As-contaminated soils (19 acidic, 20 alkaline). Each soil was divided into ‘untreated’ and ‘RM+G treated’ groups in 5 L pots. After incubation, rice was cultivated for five months and harvested, with subsequent analysis of soil pH, DOC, and rice As concentrations. Results indicate that in most cases, the RM+G treatment maintained or lowered soil pH compared to untreated soils, with exceptions in 3 acidic and 3 alkaline soils. Despite RM’s alkalizing effect, G effectively countered this. Additionally, RM+G treatment reduced soil DOC levels in the majority of soils, except for 1 acidic and 2 alkaline soils. In acidic soils, the RM+G treatment significantly reduced rice As concentrations exceeding the Korean threshold (0.5 mg kg-1), from 7 instances in untreated soils to 1 instance. However, in alkaline soils, the number of instances exceeding the threshold increased from 10 in untreated soils to 15 in RM+G treated soils, indicating varied effectiveness. Overall, while RM and G combined effectively reduce plant-available As in acidic soils, their efficacy in alkaline soils shows mixed results, suggesting the need for tailored approaches based on soil characteristics. Arsenic concentrations in rice grown in untreated and red mud+phosphogypsum (RM+G) treated soils (Redline: converted Korean threshold of arsenic in rice from inorganic arsenic into total arsenic). - COLLAPSE
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Original research article
- Assessment of yield and cadmium (Cd) concentration dynamics of rice (Oryza sativa L.) in paddy soils with various levels of Cd contamination
- Ha-Il Jung, Chaw Su Lwin, Myung-Sook Kim, Eun-Jin Lee, Tae-Gu Lee, Seung-Gyu Lee, Yeonkyu Sonn, Byunghwan Seo, Woori Go, Songrae Cho, Danbi Lee
- Cadmium (Cd) contamination in agricultural land poses a serious threat to human health due to the absorption of this toxic element by …
- Cadmium (Cd) contamination in agricultural land poses a serious threat to human health due to the absorption of this toxic element by crops. This research aims to evaluate the effects of Cd at different soil contamination levels on yield and Cd concentration of rice (Oryza sativa L.). Rice was grown under controlled greenhouse conditions with seven different concentrations of Cd (0.1 [control], 1.9, 3.6, 7.2, 8.5, and 10.3 mg kg-1) to investigate changes in soil chemical properties and their effects on rice growth and yield. The total Cd content in the soil was significantly and positively correlated with organic matter (OM) and P2O5 levels. As soil Cd concentration increased, negative correlations were observed with key rice growth parameters, including the panicle number per plant, yields, and tiller number after 60 days. The total (CdTotal) and plant-available (CdMehlich3) Cd concentrations in soil were found to be 4.787 and 2.733 mg kg-1, respectively, and the Cd concentration in polished rice reached the edible limit of 0.2 mg kg-1. This study provides valuable insights into the relationship between soil Cd contamination, plant-available Cd concentration, and Cd accumulation in polished rice. By understanding these dynamics, effective standards can be established to assess and mitigate the risk of Cd contamination in agricultural environments. Relationship between total (A, CdTotal) and plant-available (B, CdMehlich3) Cd concentrations in soil and accumulated Cd concentrations in polished rice. - COLLAPSE
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Original research article
- Nutrient runoff and rice yield in rice paddies under different water management regimes
- Seung-Gyu Lee, Eun-Jin Lee, Ha-Il Jung, Myung-Sook Kim, Tae-Gu Lee
- Climate change is causing a variety of environmental issues globally, and the frequency and intensity of droughts in the country are expected …
- Climate change is causing a variety of environmental issues globally, and the frequency and intensity of droughts in the country are expected to increase. This has heightened the importance of managing agricultural water resources and necessitated the adoption of more efficient farming practices. In this study, we evaluated water inflow, outflow, nutrient concentration, and rice yield under continuous flooding (CF), alternate wetting and drying (AWD) in paddy soils with two different soil textures. AWD proved effective in saving water, as it increased rainfall infiltration and reduced irrigation water input compared to CF. Specifically, in silty clay loam (SiCL) soils, AWD resulted in less water and nutrient outflow than CF. Rice yields increased by 16.4% under AWD compared to CF in SiCL soils, and by 31.9% in sandy loam (SL) soils. These results suggest that water management practices can help mitigate the impact of climate change on irrigation water shortages and increase rice yields across various soil textures compared to conventional farming practices. The amount of nutrients losses due to runoff during cultivation. Treatment Runoff (mm) Nutrient runoff (kg 10a-1) NH4+-N NO3--N PO43- K SiCL - CF 202.3 a 0.106 a 0.058 a 0.017 ab 0.469 a SiCL - AWD 52.9 b 0.011 b 0.001 b 0.000 b 0.050 b SL - CF 178.3 a 0.097 a 0.021 ab 0.035 a 0.312 a SL - AWD 175.8 a 0.074 a 0.025 ab 0.030 a 0.397 a Different letters are significantly different at p < 0.05 according to Duncan’s multipe range test. - COLLAPSE
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Short communication
- Validating Korean model by estimating soil available water content under soybean cultivation for upland drought forecasting
- Se-In Lee, Jung-hun Ok, Seon-ah Hwang, Dong-hyun Kim, Seung-oh Hur
- Climate change is increasing the frequency of extreme weather events such as heatwaves, heavy rainfall, and drought. This is concerning for agricultural …
- Climate change is increasing the frequency of extreme weather events such as heatwaves, heavy rainfall, and drought. This is concerning for agricultural fields that rely on natural rainfall, as drought can significantly impact crop growth and yield. To address the annually recurring upland drought, model for assessing upland drought based on soil available water content (SAWC) has been used to provide weekly drought forecast and warning. This study was conducted to validate the accuracy of model for assessing upland drought. As a result of comparing SAWC estimated at given reference date (SAWCe) and SAWC predicted one week before for the reference date (SAWCp) on a weekly basis, it was demonstrated that the prediction of model was reliable, with r2 = 0.91 (P < 0.001) and NSE = 0.89. The differences between SAWCe and SAWCp ranged from -18.5% to +29.2%, attributed to variations in evapotranspiration and water stress coefficient. Comparing the measured SAWC collected from soybean fields in five regions across the country (SAWCm) and SAWCe, the r2 values ranged from 0.54 to 0.78, and the RMSE ranged from 12.9 to 27.4. The differences between SAWCm and SAWCe ranged from -6.3% to +46.4%. Our results suggest that to reduce the error and improve the accuracy of upland drought assessment model, it is important to estimate evapotranspiration more precisely, additionally, to consider wide range of factors including soil structure and organic matter content. Correlation between SAWC predicted one week before for the reference date (SAWCp) and SAWC estimated at given reference date (SAWCe) by model for assessing upland drought. - COLLAPSE
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Opinion
- Too much biochar is not better than nothing
- Nuri Baek, Husna Israt Pia, Seo-Woo Park, Eun-Seo Shin, Sun-Il Lee, Woo-Jung Choi
- This study investigated the benefits and potential risks of biochar application using literature data on CH4 emission from paddy fields (n …
- This study investigated the benefits and potential risks of biochar application using literature data on CH4 emission from paddy fields (n = 107) and N2O from upland fields (n = 174). Literature data indicated that biochar application decreases a substantial amount of CH4 (by 14.4%) from paddy and N2O (by 22.9%) from upland fields. However, the regression analysis between biochar application and greenhouse gas (GHG) mitigation was not significant, suggesting that the performance of biochar on GHG reduction is not additive due to the diminished capacity of unit-weight biochar to mitigate GHG with increased biochar application rate. Besides, it is also warned that heavy application of biochar may cause soil and food contamination and ecological toxicity because of toxic compounds such as polycyclic aromatic hydrocarbon and heavy metals contained in biochar. An optimal biochar application rate by considering these potential risks of biochar needs to be established to take full advantage of biochar to mitigate GHG and enhance soil carbon sequestration. Optimal application of biochar for carbon sequestration, GHG mitigation, food security and safety, and soil and ecological health. - COLLAPSE
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Opinion
- How to determine the organic carbon content of reclaimed tideland soils containing inorganic carbon?
- Seo-Woo Park, Nuri Baek, Eun-Seo Shin, Bo-Seong Seo, Kwang-Seung Lee, Bang-Hun Kang, Woo-Jung Choi
- Reclaimed tideland (RTL) soils, which are created in the coastal area may play a sink role of atmospheric CO2 with cultivation …
- Reclaimed tideland (RTL) soils, which are created in the coastal area may play a sink role of atmospheric CO2 with cultivation due to their low soil organic carbon (SOC) content. The wet oxidation method with an oxidizing reagent (e.g., K2Cr2O7) and the dry combustion method using elemental analyzers are conventionally used to determine the SOC content of RTL soils. The RTL soils are characterized by the presence of inorganic carbonate and chloride (Cl-), which may potentially interfere with the SOC analysis. In this study, we explored the potential limitation of SOC determination using these methods to suggest a suitable method for the determination of SOC of RTL soils. Using wet oxidation, SOC is specifically determined by ruling out the potential interference of carbonate. However, Cl- is also oxidized to Cl2 by consuming the oxidizing reagent, leading to an overestimation of SOC. Therefore, the removal of Cl via precipitation with Ag2SO4 is required. Dry combustion is a quick and simple method for the analysis of SOC. However, not only SOC but also inorganic C is combusted to CO2, resulting in an overestimation of SOC. Although several methods for the removal of carbonate using acids are proposed, the procedure is time-consuming and inaccurate, and the residual acid may cause instrument failure. Most critically, acid treatment may deteriorate SOC to cause an underestimation of SOC. Given the advantages and disadvantages of the methods, we suggest that the wet oxidation after the removal of Cl- interference is the most suitable procedure for the determination of SOC for RTL soils. Interference of the analysis of the organic carbon (OC) content of reclaimed tideland soils with CaCO3 and Cl-. CaCO3 is combusted to CO2 with the dry combustion and Cl- is oxidized to Cl2 with the wet oxidation, both resulting in an overestimation of OC. - COLLAPSE
Journal Informaiton
Korean Journal of Soil Science and Fertilizer
Korean Journal of Soil Science and Fertilizer
Korean Society of Soil Science and Fertilizer
한국토양비료학회
Room 313, National Institute of Agricultural Science, 166, Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do, Korea, 55365
Tel: +82-63-226-7335 / Fax: +82-63-226-7335 / E-mail: ksssf733@naver.com Copyright© Korean Society of Soil Science and Fertilizer. Powered by APUB
Tel: +82-63-226-7335 / Fax: +82-63-226-7335 / E-mail: ksssf733@naver.com Copyright© Korean Society of Soil Science and Fertilizer. Powered by APUB
