• Korean Journal of Soil Science and Fertilizer
• /
• v.48 no.4
• /
• pp.285-294
• /
• 2015

Ordination has been recognized useful method to analyze the effects of multiple environmental factors on dozens of species in vegetation ecology because of summarizing community data by producing a low-dimensional graphics. Main objective of this study was the application of ordination method, especially principal components analysis (PCA), to analyze the soil characterization on paddy treated by different green manure crops and tillage methods. Treatments included the three tillage treatments and two green manure crops as the following; (i) moldrotary + rotary tillage without green manure crop (Con), with (ii) hairy vetch (ConHv), and (iii) hairy vetch + green barely (ConHvGb), (iv) rotary tillage without green manure crop (Rot), with (v) hairy vetch (RotHv), and (vi) hairy vetch + green barly (RotHvGb), and (vii) no-tillage (Notill). Vectorial distance result from PCA of soil properties including physical, chemical, and microbial properties showed the two main difference. Firstly, soil properties among plots without green manure were strongly affected by tillage strength [Vectorial distance: Con-Notil (5.88) > Rot-Notill (4.58)] at PC1 (35.0%) axis. But it was difficult to find the fixed trend among plots when green manure crop was added in plot. Nevertheless, two groups were separated by adding green manure crop at PC2 (29.2%) axis. These results show that PCA ordination methods could be used the research for change of soil characterization.

• Journal of Biosystems Engineering
• /
• v.26 no.3
• /
• pp.221-228
• /
• 2001

Chemical application, one of the most important crop management processes happened to cause spray drift, that would threaten farmers in field as well as dwellers in rural region. Spray drift was affected by micro-meteorological parameters. A study to evaluate short distance drift characteristics of a boom sprayer in paddy fields has been undergoing. This study is the first step of the research. Main purpose of the was conducted to develop a mean wind profile and to get information on turbulence intensities above and within rice canopy. Wind in rice paddy field were measured at every 10cm from 10 to 180cm above the ground using a 2-dimensional probe and a hot wire anemometer system. Main results were summarized as follows. 1. Mean wind profile was modeled as; Equations. see full-text 2. Roughness length and zero-displacement in rice canopy were analyzed to be respectively 0.04 and 0.7∼0.72 times of the canopy height. The values are smaller comparing to those of other crops because rice canopy is flexible and uniform comparing to other crops. 3. Turbulence intensities (Tl) was greater as close to the ground and became constant at heights greater than 1.5Hc. where Tl’s were 0.4 and 0.15 in horizontal and vertical direction respectively.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.108-115
• /
• 1991

A field experiment was conducted to evaluate the effects of cattle compost application on the change of soil physical properties and their relationship to yield performance of selected main forage crops. Maize(CV. Suweon 19) and sorghum hybrids(CV. Pioneer 9'31) as a summer crops and winter rye were grown on newly reclaimed red yellow soils(Fine loamy, Typic Hapludults) under different application rate of cattle compost associated with chemical NPK fertilization, from Oct. 1986 to Sept. 1989. Experimental field was laid down as a split plots design with four replications. The results obtained are summarized as follows: 1. Cattle compost application reclaimed soil physical propeties, such as formation of granular structure and water holding capacity, and it result in a great increase of plant growth and the rate of dry matter accumulation. 2. While cattle compost treatment reduced the portion of soild phase of the three phase constituents of soils, it increased the portion of air phase and liquid phase comparatively. 3. Organic matter, N, P, K, and mineral content in soil were markedly increased in the plot treated with compost. 4. Cattle compost application increased fodder production both in maize-rye and sorghum hybrids-rye cultivation. Annual dry matter yield of maize-rye cropping was 2183(NI'K only), 2425(NPK+compvst 3000 kg) and 2800kg/lOa(NPK + compost 6000kg/10a).

• Journal of Biosystems Engineering
• /
• v.24 no.5
• /
• pp.453-462
• /
• 1999

At the time of discontinuing the publishing of RDA Journal of Farm management and agricultural engineering the present paper is to review the research results produced since 1962 to 1998. During the three decades, from 1960s to 1980s, the main research efforts were focused o mechanization of rice farming which contributed in food grain productions. In the 1990s, the research direction was shifted to horticultural productions and producing high quality agricultural products. We had put stress on practical use of farm mechanization, mainly on transplanting and seeding operation for rice and upland and horticultural crops productions and harvest and threshing machinery developments, in which we thought our research direction had not been quite right. However, in the future we are going to promote mechanization on livestock and upland crops productions. Furthermore, we have a plan to employ cutting edge technologies in agricultural machinery developments in order to automate and unman all farm operations satisfying the needs of advanced agricultural mechanization technology in the twenty first century.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.3
• /
• pp.445-448
• /
• 1999

Beef and dairy cattle are the primary ruminant livestock in Korea, but there is a serious shortage of both fresh and dry forages. Small areas of forage crops or pastures, unfavorable soil and climatic conditions, high costs for pasture production, low establishment and management technologies, etc. are the main factors limiting roughage production in Korea. To meet the roughage demand of cattle several suggestions are presented. About 845,000 ha of hilly area could be developed for pastureland. Almost the same area of paddy field, and more than 200,000 ha of reclaimed land could be used for pasture production. If all the potential area is developed for pastureland, the area could be extended to 10 times more than is presently used for pasture crops and pastureland. Productivity would be increased by developing new technologies of establishment and management. Silvo-pastoral systems should be introduced to Korea.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.15 no.4
• /
• pp.245-252
• /
• 1995

To select a carrier as Rhizobiwn inoculants for alfalfa, severeal Rhizobium inoculants were produced by adding or not sub-materials($CaCO_3$ and sucrose) to main materials(organic or inorganic materials). The root nodule bacteria, Rhizobium meliloti 1061 distributed from KAIST, and Vemal alfalfa was used in this experiment. The Rhizobium populations and inoculation effects of the Rhizobium inoculants produced in several materials were scrutinized at laboratory and greenhouse in Livestock Experiment Station, RDA from 1993 to 1994. Moisture contents of the caniers were varied from 32 to 50% on dry weight basis according to material characteristics and the pH ranges of these were varied from pH 4.56 to 10.06 according to raw material characteristics and preparations. Initial Rhizobium numbers of the carriers were higher in organic material-inoculants than in inorganic, and among the inoculants, the inoculant made of Bentonite+Vermiculite(l:3 w/w) was excellent because of high rhizobium population($7.8~8.3\times10^8/g$ inoculant) and high rhizobium reappearance of inoculant in severed different production time. The root nodules of the alfalfa inoculated with different inoculants were fast formed in the fermented sawdust with cattle dung (FSC) inoculant, and bentonite(B)+vermiculite(V) than others. Plant length of alfalfa was differentiated on 15 days after inoculation but was not nearly different between higher inoculants than rhizobium number $10^7/g$ inoculant. Total dry matter of alfalfa was yielded by 20.65, 20.34mg per pot in FSC + sucrose 0.5% and B + V + sucrose 1% inoculants respectively that were higher inoculation effect by 17 times compared with non-inoculation, 1.2 mg per pot.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.15 no.4
• /
• pp.253-258
• /
• 1995

'Ihis experiment was carried out to select a carrier as rhizobium inoculant for alfalfa. The Rhizobium inoculants were produced in main materials(organic and inorganic materials) and submaterial(Ca$CO_3$, and sucrose), and than the changes of Rhizobium population of inoculants were scrutinized from directly after the production to 12 months at $4^{\circ}$C and $25^{\circ}$C. Directly after the production of inoculants, their Rhizobium numbers were 4-9 $\times$ $10^9$/ginoculant in organic materials and 1-8 $\times$ $10^8$/g inoculant in inorganic materials. When they were stored at $25^{\circ}$C, most of inoculants was being started in reduction of rhizobium numbers after 2 months and was reduced by tenfold of initial rhizobium number after 4-6 months, but inoculant of bentonite+ vermiculite+sucrose 1% was not reduced by tenfold after 12 months. When they were stored at $4^{\circ}$C, most of inoculants was being started in reduction of rhizobium numbers after 4 months but was not reduced by tenfold of initial rhizobium number after 12 months, and the effect of sucrose addition to bentonite+ vermiculik did nearly not appear. Preservation of Rhizobium inoculants was more effective at 4C than 25 C . 'Ihe Rhizobium inoalant produced in bentonite+vermiculite(l:3 w/w)+ sucrose 1% was not only high Rhizobium population(8.3 $\times$ $10^8$/g inoculant) but also survival effect of rhizobium in being stored at $25^{\circ}$C.

• The Plant Pathology Journal
• /
• v.35 no.6
• /
• pp.553-563
• /
• 2019

Investigations related with factors influencing root and crown rot are rare and mainly related to farming practice and soil management. The main objective of this study was to examine broader range of factors influencing stem-base infestation of winter wheat in the field conditions. The effect of spatial distribution of infected plants on disease index (DIs) assessments was also investigated. Analysis of factors influencing DIs of crown rot of wheat demonstrated significant influence of the growing seasons (P < 0.001) and extreme fluctuations in winter temperatures (P < 0.001). In addition to that, localities together with their interaction with the growing season also significantly influenced DIs (P < 0.001). Aggregation of infected plants influenced variability of DI estimations, and it was pointed out that more extensive investigation should be conducted on broad range of DI in order to establish sampling method giving uniform sampling precision. Fusarium graminearum was shown to be predominant Fusarium species in Serbia (72.6%) using sequence-characterized amplified region analysis. Interestingly F. oxysporum was isolated in higher frequencies (27.4%) than it was reported in the literature. Given that there were no reports on the diversity of Fusarium species causing crown rot of wheat in Serbia, this study presents first report on this important subject. It also indicated that more attention should be focused on combined effects of abiotic and biotic factors influencing stem-base infestation of winter wheat. This knowledge will contribute to better understanding of factors influencing root and crown rot of wheat which would ensure sustainable disease management in the future.

• The Plant Pathology Journal
• /
• v.28 no.2
• /
• pp.185-190
• /
• 2012

Sclerotinia sclerotiorum is a serious pathogen which causes yield loss in many dicotyledonous crops including potato. The objective of this study was to assess the potential of biofumigation using three Brassica crops including Brassica napus, B. juncea and B. campestris against potato stem rot caused by S. sclerotiorum by in vitro tests. Both macerated and irradiated dried tissues were able to reduce radial growth and sclerotia formation of five pathogen isolates on PDA, but macerated live tissues were more effective. Compared with other tested crops, B. juncea showed more inhibitory effect against the pathogen. The volatile compounds produced from macerated tissues were identified using a gas chromatograph-mass spectrometer. The main identified compounds were methyl, allyl and butyl isothiocyanates. Different concentrations of these compounds inhibited mycelial growth of the pathogen in vitro when applied as the vapor of pure chemicals. A negative relationship was observed between chemicals concentrations and growth inhibition percentage. In this study, it became clear that the tissues of local Brassica crops release glucosinolates and have a good potential to be used against the pathogen in field examinations.

• Korean Journal of Soil Science and Fertilizer
• /
• v.49 no.3
• /
• pp.242-250
• /
• 2016

Veterinary antibiotics (VAs) has been used to treat animal disease and to increase animal weight as growth promoter. However, abused usage of VAs can cause production of antibiotic resistance genes (ARGs) in the environment and additionally, residual of VAs in soil can be transferred into crops. Therefore, main objective of this research was to examine bioaccumulation of VAs in sprouts (red cabbage, Brassica Olearacea L. var. Capitata f. rubra and red radish, Raphanus sativus) with hydroponic method. Total of 7 VAs in 2 different classes of VAs (tetracyclcines: tetracycline, oxytetracycline, chlortetracycline, sulfonamides: sulfamethoxazole, sulfamethazine, sulfamethiazole, macrolides: tylosin) were evaluated and experiment was conducted with solid phase extraction (SPE)/high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). Initial spiked concentration of 7 VAs was $5mg\;L^{-1}$ and cultivation period was 8 days. Result showed that growth of sprouts was inhibited about 23-27% when VAs was introduced. Amount of bioaccumulated VAs was also differed depending on class of VAs. The highest amount of bioaccmulated VAs was tetracycline and sulfamethoxazole in each class with a concentration of 4.05, $7.73mg\;kg^{-1}$ respectively. Calculated transfer ratio of VAs into crops was also ranged 0.38-54.27%. Overall, bioaccumulation of VAs in crops can be varied depending on crop species and class of VAs. However, further research should be conducted to verify bioaccumulation of VAs in crops in the soil environment.