• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.108-113
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• 2022

Arsenic (As) uptake and accumulation from agricultural soil to rice vary depending on the soil environmental conditions such as soil pH, redox potential, clay content, and organic matter (OM) content. Therefore, these factors are important in predicting changes in the uptake and accumulation of As in rice plants. Here, we studied the chemical properties of As-contaminated and/or rice straw compost (RSC)-treated soils, the growth responses of RSC-applied rice plants under As-contaminated soils, the changes in As content of soil, and the relationship between As uptake and accumulation from the RSC-treated soils to the rice organs under As-contaminated soils. Rice plants were cultivated in 30 mg kg^-1 As-contaminated soils under three RSC treatments: 0 (control), 12, and 24 Mg ha^-1. No significant differences were indicated in the chemical properties of pre-experimental (before transplanting rice seedling) soils, with the exception of EC, OM, and available P₂O₅. As the treatment of RSC under 30 mg kg^-1 As-contaminated soils increased, EC, OM, and available P₂O₅ increased proportionally in soil. Increased soil RSC under As-contaminated soils increased shoot dry weight of rice plants at harvesting stage. As content in roots increased proportionally with RSC content, whereas As content in shoots decreased under As-contaminated soil at all stages of rice plants. Nevertheless, As accumulation were significantly decreased in both roots and shoots of RSC-treated rice plants than those in the plants treated without RSC. These results indicate that the use of RSC can mitigate As phytotoxicity and reduce As accumulation in rice plants under As-contaminated soils. Therefore, RSC can potentially be applied to As-contaminated soil for safe crop and forage rice production.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.318-324
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• 2017

Lime bordeaux mixture (LBM) and lime sulfur mixture (LSM) are representative environmental friendly organic materials for prevention of insect pests in South Korea. Recently, those have been widely used as an alternative for chemical pesticides in eco-friendly farms. However, South Korea has not established even recommendation of LBM and LSM considering the stability of heavy metals in soil. The aim of this study was to evaluate the accumulation of hazardous heavy metals in soil and plant with long-term application of LBM and LSM. Firstly, we investigated the amount of LBM and LSM used per year in several eco-friendly farms to determine a standard application rate of both materials. The pepper plant was grown on the pot in greenhouse for 14 weeks. Both materials were applied at 0, 1, 3, and 9 times of standard application rates (2.56 and $1.28L\;ha^{-1}$ of LBM and LSM per year, respectively). Dry matter yield of pepper and heavy metals (As, Cd, Cu, Hg, Ni, Pb, and Zn) concentration in soil and pepper plant were measured after 14 weeks. Yield of pepper plant did not significantly chang with up to application rate of 1 times, thereafter it markedly decreased with more than 3 times. With increasing LBM and LSM application, the concentration of Cu and Zn in soil significantly increased. Especially, Zn concentration in pepper significantly increased with increasing application rates of both materials. This might resulted in significant decrease in dry matter yield of pepper. The concentrations of those heavy metals in soil did not exceed safety levels ($150mg\;kg^{-1}$ for Cu and $300mg\;kg^{-1}$ for Zn) established by the Korean Soil Environmental Conservation Act as well as concentration of heavy metals in pepper plant by Korean Ministry of Food and Drug Safety. However, particular attention should be paid for heavy metal safety and crop productivity when using LBM and LSM in the organic farm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.196-207
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• 2016

In monsoon climates, persistent shade is a troublesome weather condition with an impact on the growth and yield of corn (Zea mays L.). We imposed 7, 14, 21, and 28 days of consecutive shade (CS) on Gwangpyeongok and P3394 corn hybrids at the beginning of the kernel filling stages. Shade had little impact on leaf area and dry matter accumulation in the stem and leaves. However, dry matter accumulation in the ear was severely reduced by approximately 28% and 53% after 14 and 28 days of CS, respectively. For the components of grain yield, 7 and 14 days of shade did irreparable damage to the number of filled kernels, the kernel number per ear row, and the percent of filled kernels, but did little damage or reversible damage after removal of the shade to the 100-grain weight and the row number per ear. Shade significantly reduced the relative growth rate (RGR) due to a decrease in the net assimilation rate (NAR). These results suggest that source activity limitation by shade during the kernel filling stages leads to the inhibition of sink activity and size. The yield of biomass, ear, and grain logistically declined as the length of CS increased. Probit analysis revealed that the number of days of CS needed to cause 25% and 50% reductions in grain yield were 3.7 and 23.1, respectively. These results suggest that the plant yield loss induced by shade at the beginning of the kernel filling stages is mainly achieved within the first 7 days of consecutive shade.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.26-31
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• 2000

This study was carried out to obtain the basic information for breeding cold-tolerant rice varieties with high yield-productivity through wide crosses between indica and japonica rice. Genetic analysis was conducted using 55 F$_1$s obtained from half-diallel crosses among eleven cultivars of various origin including indica and japonica rice. Screening for cold tolerance was done with cold-water irrigation after transplanting until ripening stage. Both general combining ability (GCA) and specific combining ability (SCA) effects were highly significant in all characters associated with dry matter accumulation at 30 and 50days after cold-water irrigation (DAC). The variance of GCA was much larger than that of SCA in plant height, shoot dry weight per plant (DWP), crop growth rate (CGR) and cold-water response index (CRI) of these characters except CRI of shoot dry weight per plant. The DWP, CGR and CRI of these characters of Gaochan 102, Tong88-7 and TR22183 were markedly higher than those of the others. GCA effects of these varieties on DWP, CGR and their CRI were also higher than those of the others, indicating that they are useful as promising parents for breeding cold-tolerant varieties. Analysis of genetic parameters for 11$\times$11 half-diallel F$_1$s revealed that inter-locus gene interaction were concerned in the expression of plant height at 50 DAC, CRI of DWP at 50 DAC, and CRI of CGR, and that intra-locus gene interaction for plant height and the other characters were partial dominance and over-dominance, respectively. Narrow-sense heritability (h$^2$$_{N}$) was the highest in plant height as 0.729, and the lowest in CRI of DWP at 30 DAC as 0.048, suggesting that selection for cold tolerance will be quite effective in case that the selection criterion is the performance itself.f.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.50-59
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• 2008

A greenhouse experiment was conducted to investigate the role of the arbuscular mycorrhizal(AM) fungus, Glomus mosseae(BEG 107) in enhancing growth and arsenic(As) and phosphorus(P) uptake of white clover(Trifolium repens) and evening primrose(Oenothera odorata) in soil collected from a gold mine having concentrations of 381.6 mg total As $kg^{-1}$ and 20.5 mg available As $kg^{-1}$. Trifolium repens and O. odorata are widely distributed on abandoned metalliferous mines in Korea. The percent root colonization by the AM fungus was 55.9% and 62.3% in T. repens and O. odorata, respectively, whereas no root colonization was detected in control plants grown in a sterile medium. The shoot dry weight of T. repens and O. odorata was increased by 323 and 117% in the AM plants compared to non-mycorrhizal(NAM) plants, respectively. The root dry weight increased up to 24% in T. repens and 70% in O. odorata following AM colonization compared to control plants. Mycorrhizal colonization increased the accumulation of As in the root tissues of T. repens and O. odorata by 99.7 and 91.7% compared to the NAM plants, respectively. The total uptake of P following AM colonization increased by 50% in T. repens and 70% in O. odorata, whereas the P concentration was higher in NAM plants than in the AM plants. Colonization with AM fungi increased the As resistance of the host plants to As toxicity by augmenting the yield of dry matter and increasing the total P uptake. Hence, the application of an AM fungus can effectively improve the phytoremediation capability of T. repens and O. odorata in As-contaminated soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.594-601
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• 1994

Effects of translocation on seed yield and carbon-nitrogen compounds at five leaf-pod ratios of soybean [Glycine max. (L.)Merr. ] culti bars, 'Paldalkong', 'Baekunkong', and 'Danyeobkong' were measured. The upper 50 and lower 50% of leaves and pods were subjected to treatments at growth stage R3. Three soybean cultivars showed the similar trends on changes in dry matter accumulation and on the contents of soluble sugar, starch and protein in seeds among the treatments. Mean stem dry weight was increased with upper leaf-lower pod and lower leaf-upper pod removals, and decreased with upper leaf and lower leaf removals. Leaf dry weight was appeared higher at the upper leaves among the treatments. Seed numbers and dry weights were decreased with leaf and leaf-pod removals, and were higher in lower part of the plants. Soluble sugar and starch contents in seeds were also showed slightly higher in lower part. Protein content of seeds was decreased in upper part with upper leaf removal and in lower part with lower leaf removal, however, that of the upper seeds was the highest with lower leaf removal. The results of this study are assumed that carbon and nitrogen compounds were translocated opposite directions and protein source was weak in remobilization for the long distance transport during the reproductive growth period of soybean plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.139-143
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• 2010

The relationship between ADP-glucose pyrophosphorylase (AGP) activity and the characteristics of related pod setting in developing seed of soybean cv. Pungsannamulkong, Iksannamulkong, Geumjeongkong #1 and Danpaheuk was studied. AGP activity during the accumulate of the majority of dry matter in all cultivars suggested that this enzyme might be associated with this process. At the Vn and R1 stages, AGP activity of full-grown leaves of Pungsannamulkong, Iksannamulkong, Geumjeongkong #1 was the highest and then decreased progressively. However AGP activity of Danpaheuk was the lowest and also had lower seed weight. So regulation of matter accumulation in developing soybean seeds may also depend on AGP activity. AGP capacities as expressed by AGP activity seem to have a good predicting value for the dry matter of leaf and seed at R1 to R5 stages in our series of R3 stage genotypes. Western blots probed with antibody specific to the subunit of potato AGP revealed a single 60KD immunoreactive band that changed in intensity during the growth cycle in association with changes in total AGP activity.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.200-207
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• 2007

In vitro rumen incubation studies were conducted to determine effects of initial pH on bacterial attachment and fiber digestion. Ruminal fluid pH was adjusted to 5.7, 6.2 and 6.7, and three major fibrolytic bacteria attached to rice straw in the mixed culture were quantified with real-time PCR. The numbers of attached and unattached Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminocococcus albus were lower (p<0.05) at initial pH of 5.7 without significant difference between those at higher initial pH. Lowering incubation media pH to 5.7 also increased bacterial numbers detached from substrate regardless of bacterial species. Dry matter digestibility, gas accumulation and total VFA production were pH-dependent. Unlike bacterial attachment, maintaining an initial pH of 6.7 increased digestion over initial pH of 6.2. After 48 h in vitro rumen fermentation, average increases in DM digestion, gas accumulation, and total VFA production at initial pH of 6.2 and 6.7 were 2.8 and 4.4, 2.0 and 3.0, and 1.2 and 1.6 times those at initial pH of 5.7, respectively. The lag time to reach above 2% DM digestibility at low initial pH was taken more times (8 h) than at high and middle initial pH (4 h). Current data clearly indicate that ruminal pH is one of the important determinants of fiber digestion, which is modulated via the effect on bacterial attachment to fiber substrates.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.81-88
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• 2001

To investigate C and N metabolisms in response to potassium-deficient stress during regrowth of Italian ryegrass(Lolium multiflorum L.), C and N metabolites were analyzed at day 0 (cutting date), 6, 12 and 24 days after defoliation. K-sufficient (control, +K) and K-absent (-K) nutrition solutions were applied from 7 days before defoliation, and continued for one cycle of 24 days-regrowth period. During 24 days of regrowth dry matter of regrowing shoots and remaining tissues were not significantly different between +K and -K treatment. In remaining stubble, all C compounds in both +K and -K treatment largely decreased (69% to 84% of the initial level) during the first 6 days of regrowth, and then rapidly recovered. The decline of soluble sugars and fructan in roots for the first 6 days much less in the -K medium. Amino acids, soluble and insoluble proteins in stubble also feel down during the first 6 days, thereafter actively replenished in both +K and -K treatment. The decline of nitrate in stubble prolonged to 12 days of regrowth. Initial amounts of all N compounds in roots were significantly lower in the -K medium. Higher accumulation of amino acids and soluble protein in roots in the -K medium was observed after 12 days of regrowth. In regrowing shoots, 3 all carbohydrates increased with a very similar pattern for both treatments. Nitrate was not significantly different between two treatments. Depress of soluble protein accumulation in -K medium was noteworthy after 12 days of regrowth. These results indicated that an active utilization of organic reserves occurred to support regrowth even under K deficient condition with a similar extent with K sufficient condition.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.4
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• pp.347-351
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• 1990

A simple cross-over design was used in digestion experiment carried out on finishing pig (70 kg body wt.) fitted with ileal T-cannula, to determine the difference between ileal and fecal digestible values as affected by various fiber sources and levels. The series of semi-purified diets were formulated in an attempt to meet 1, 3, 7 and 9% crude fiber level, with alfalfa meal (AFM), rubber seed meal (RSM), leucaena meal (LM) and cellulose. Both the levels and sources influenced the amino acid digestibilities, as increasing crude fiber level the digestibilities increased. The digestibilities of amino acids at ileal level were higher than at fecal level. The magnitude of response were ranged from 1.76 to 8.41 percentage unit or 4.86 by average. The dry matter digestibilities of the diets reflect the digestibilities of amino acids as accumulation of fiber would increase endogenous losses. It indicates that the digestibilities of amino acids varied irregularly among diets, probably depended on a dietary nutrient and individual fiber fraction contents.