• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.159-164
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• 2021

Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

• Korean Journal of Environmental Agriculture
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• v.39 no.2
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• pp.95-105
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• 2020

BACKGROUND: In this study, in order to verify the effects of supplemented organic amendment fertilizers recommended by the soil testing on cabbages, we used various amounts of organic amendment fertilizers. The amount of organic amendment fertilizers was decided by calculating each ratio of inorganic nitrogen, phosphorus, and potassium based on the recommended fertilizer composition. METHODS AND RESULTS: The cabbages subjected to treatments 1 and 2 showed similar or greater leaf colors (SPAD values), head heights, head widths, head weight, soil organic matter content, nitrate-nitrogen level, and conductivity after harvest, when compared with cabbages treated with chemical fertilizers. The phosphorus and potassium fixation in the soil were higher in the plot where cabbages were treated with chemical fertilizers, and the nutrient use efficiency was greater in the plots with organic amendments and mineral addition. CONCLUSION: The treatments 1 and 2 that were supplemented with 180-200% of nitrogen, 100-130% of phosphorus, and 185-250% of potassium in comparison to chemical fertilizers, applied by the inorganic ratios of nitrogen, phosphorus, and potassium can be used as organic amendment fertilizers for cabbages.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.467-474
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• 2012

This study was carried out to evaluate effect of temperature condition on nitrogen mineralization of organic matter, distribution of microbial group by PLFA profiles, and soil microbial community structure in volcanic ash soil. Dried soil 30 g mixed well each 2 g of pellet (OFPE) organic fertilizers, pig manure compost (PMC), and food waste compost (FWC). And then had incubated at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, respectively. Nitrogen mineralization rate increased with increasing temperature and that was in the order of FWC>OFPE>PMC. Distribution ratio of microbial group by PLFA profiles were different significantly caused by incubation temperature and the type of organic matter. As incubating time passed, density of microbial group decreased gradually. The Gram-bacteria PLFA/Gram+ bacteria PLFA, Fungi PLFA/Bacteria PLFA, and Unsaturated PLFA/saturated PLFA ratios were decreased according to the increasing temperature gradually. But cy19:0/$18:1{\omega}7c$ ratio increased both FWC and PMC treatment. Principal component analysis using PLFA profiles showed that microbial community structure made up clearly at both 75 days ($10^{\circ}C$) and 270 days ($30^{\circ}C$) by temperature factor. As incubating time passed, microbial community structure shifted gradually.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.381-387
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• 2016

The scientific information on the microbial differentiation according to the changes in chemical properties of paddy soil in reclaimed tidal lands is not enough to understand the reclamation processes. The changes in microflora based on the chemical properties of paddy soils at the same sites of reclaimed tidal lands (21 samples from Nampo, Ewon, Sukmoon and Shihwa sites) were investigated in 2013 and 2015. In general, organic matter in paddy soils increased whereas pH decreased with the reclamation time. The electrical conductivities (EC) of soil samples were closely related to the exchangeable $Na^+$. With an increases in EC of paddy soils from 0.39 to $48.9dS\;m^{-1}$, the ratios (%) of halotolerant and halophilic bacteria to mesophilic bacteria proportionally increased from 0.2% to 102,000%. The population of halotolerant and halophilic bacteria in total microflora was also differentiated with the changes in EC of the same sites from reclaimed tidal soils within 2 years. The population of mesophilic bacteria decreased with an increase in EC above $5dS\;m^{-1}$. The microflora including halotolerant and halophilic bacteria could be a candidate as a biological parameter in evaluating the reclamation processes in addition to the chemical index of EC.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.67-76
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• 1984

This experiment was conducted to find out the changes in microflora of submerged soil uncultivated rice plant by application of CNP herbicide (2, 4, 6 - Trichlorophenyl-4-Nitrophenyl ether) under conditions applied with compost, rice straw, glucose or without organic material. The soil, sandy loam textured was incubated in green house for 66 days. Sampling and analysis of microorganisms were carried out during submergence periods. The results were summarilized as follows. 1. Number of aerobic total bacteria was increased by application of CNP herbicide during submerbed 50 days, afterthen, could not seen the difference. The application of rice straw increased number of aerobic bacteria regardless of CNP herbicide application or not, but glucose tended to decrease. 2. Number of Fungi was constantly maintained at $8-20{\times}10^3$ levels during period of submergence regardless of application of CNP herbicide and organic materials or not. 3. The CNP herbicide application tended to decrease the number of actinomycetes, particularly, in the treatments without organic substances and rice straw were remarkably decreased. 4. Anaerobic-and gram-negative bacteria populations were not showed any difference by application of herbicide and organic materials. 5. The ratios of aerobic bacteria to fungi and aerobic bacteria to actinomycetes appeared high values by application of herbicide and of organic substances. 6. At 66 days after submergence, the ratio of chromogenic actinomycetes to the total number of actinomycetes was lowered in application of herbicide. On the other hand, the percentage of both pretense-positive and cellulase-positive actinomycetes to the total isolates were higher in the treatment with herbicide than An without herbicide, particularly. The ratios of pretense-positive actinomycetes were high in the rice straw application regardless of herbicide application or not, but cellulase-positive actinomycetes was not remarkably difference.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.667-673
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• 2010

Organic agriculture of especially medicinal crops has been interested and focused in taking the qualitative and safety agricultural products in order to maintain and improve the health and happiness of people. With respect to the organic agriculture relating to cropping system, objectives of this study were to examine the seedling establishment after seed germination and emergence and to investigate the early seedling growths of Astragalus membranaceus Bunge with treating two green manure crops, hairy vetch of legume and rye of gramineae, two different conditions of green manures, fresh and dry, and different seeding times. When the seeds were planted at once after treating the green manures with the fresh condition into the soil, the ratios of seedling establishment were very poor, less than 10% in hairy vetch and 20% in rye, respectively. They were increased gradually with delaying the seeding times after the treatments. With treating the green manures of dry conditions, the ratios of seedling establishment were up more than 50% in both hairy vetch and rye crops, showing that the damages of seedling establishment were more in hairy vetch than those in rye. The early seedling growths were slower in treating the green manures than those in the control, showing slow growth with fresh green manures compared to the dry. It would be very important and considered more to evaluate and utilize well the seed germination and the seedling establishment in cultivation of the organic agriculture using the green manure crops relating to the cropping system.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.131-136
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• 1998

This experiment was carried out to investigate the effect of several organic fertilizers on the growth and root yield of Achyranthes japonica N. from 1995 to 1996. Four organic fertilizers were applied: rice straw manure (RSM), fermented rice straw manure (FRSM), mixed oil cake manure (MOCM) and mighty soil manure (MSM). Organic matter, available phosphate, $K_2O$, CaO, and MgO of soil increased in all plots with the addition of organic fertilizers, specifically with MOCM application. The highest contents of total nitrogen were 6.16% for MOCM and the available phosphate contents were very high in all of organic fertilizers except MSM. RSM and MSM with C/N ratios of 22.5, 17.7, respectively, were easily decomposed but C/N ratios of FRSM and MOCM, which were considered as irresolvable organic fertilizers, were 40.9 and 8.4, respectively. FRSM and MOCM applications increased emergence rate and improved the growth characters of shoot and root parts of plants compared to those of N - P - K fertilization. The highest dry root yield resulted from FRSM 20% and MOCM 26% treatment. There were significantly positive correlations between the growth characters of shoot, root parts of plants and dry root yield in A. japonica grown under organic fertilizer applications.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.51-58
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• 2009

The compost leachate was dark-colored solution that leaches out of the bottom of the compost pile. The compost leachate was rich in nutrients and can potentially used in plant culture. In the organic production, commercial liquid fertilizer was used to insure the availability of nutrients during the formation of the yield. The cost of supplemental liquid fertilizer could be reduced by developing a fertilizer based on animal fertilizer. This experiment was conducted to investigate the effect of different combination of compost leachate and conventional inorganic solution in hydroponic culture for lettuce growth. Six different treatments were applied. The compost leachate(CL) and nutrient solution(NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80:20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of leaf lettuce. The concentration of nutrient solution was adjusted 1.5 mS/cm in EC. The compost leachate was low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). The plant height of lettuce treated with CL 20+NS 80% was similar with 100% NS of control plot. Plant height was highest in the plot of CL 20+NS 80%. The treatment of 100% compost leachate was lowest in the growth characteristics of leaf lettuce. Number of leaf was very low in 100% compost leachate compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD value was reduced in plot treated with CL100%, but CL20+NS80% plot was higher compared to 100% compost leachate. SPAD value of leaf lettuce leaves was decreased as the amount of CL was increased. The dry weight of lettuce were 107.4, 104.2g in plot of NS 100% and CL 20%+NS80%, respectively. The leaf number and plant weight were decreased at high application plots of compost leachate. The leaf lettuce showed lowest in the plot treated with 100% compost leachate, and the growth of lettuce severely decreased after application of 100% CL treatment. The results showed that compost leachate can be use as liquid fertilizer for the organic hydroponic production. The mixture solution of 20% of compost leachate and 80% of nutrient solution could be used as a nutrition solution in hydroponic culture of leaf lettuce. Our studies have shown that is possible to produce using compost leachate, although growth is slower than when using a conventional inorganic hydroponic solution.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.404-409
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• 2012

In order to obtain optimum mixing conditions with animal cadaver residue and sawdust for composting using rendering treatment method for agricultural recycling, changes of chemical characteristics and compost quality after composting were investigated. Initial mixing ratios with animal cadaver residue and sawdust were adjusted 100 : 0, 50 : 50 and 30 : 70. Temperature, pH, contents of ammonia and carbon dioxide were rapidly increased in 3 days and then decreased with time. Organic matter content was similar in all conditions. In mixing ratio of 50 : 50, the compost quality was satisfied with compost depending on official standard for product fertilizer. Thus, the optimum mixing ratio of animal cadaver residue and sawdust were 50 : 50.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.105-110
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• 1994

Field experiment was carried out to obtain the basic information on the soil improvement with different improved methods on job's tears yield and soil properties in the newly-reclaimed land from 1985 to 1988. Job's tears yield, soil properties and annual changes of soil were investigated and analyzed. Soil bulk density and hardness of topsoil decreased from 1st year to 3rd year, but those increased in 4th year. Soil pH of topsoil had no differences in different soil depths and cultivated years. Average yield of job's tears in the integrated improvement plot was 2.16ton/ha. That was increased by 49% than the control plot. Crop yield was greatest in order of integrated improvement>subsoiling>phosphate>lime>compost>control plot. Correlation coefficients of job's tears yield with soil pH and organic matter content were higher significantly. Also those of subsoil were higher than topsoil. Ratios of annual changes of soil bulk density and hardness showed significant highly with job's tears yield. Also that soil pH was significant at 5 % level in the topsoil.