• Title/Summary/Keyword: Seeding time

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Vetch Effects for the Low-input No-till Direct-Seeding Rice-Vetch Cropping System

  • Cho, Young Son;Choe, Zhin Ryong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.3
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    • pp.221-224
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    • 1999
  • A field experiment was carried out to observe the weed control effects of vetch and to evaluate vetch characteristics on clay loam soil in no-till direct-sown rice-vetch cropping systems. The effects of weed control, forage productivity, and N content of vetch plants were investigated. With the progress of plant growth, density of Chinese milk vetch (Astragalus sinicus L.) gradually decreased, but densities of foxtail and other weeds decreased steeply due to the depression by the over-shaded vetch canopy in a no-till direct-sown rice-vetch cropping paddy field. The vetch density in tillage systems was lower than in notillage cropping systems. Lower vetch density occurred with an increase in foxtail density and other weeds. Weed control effect increased by the progress of vetch growth, which indicated that the vetch canopy over-shaded the weeds. Vetch straw was degraded rapidly submergence after with water at the time of wet sowing of rice. Early harvesting of vetch seed resulted in lower seed germination. To acquire enough seedlings without re-sowing, the harvesting of seed should be delayed at least 28 days after the flowering stage in order to ensure the vetch population is sustainable in a no-till direct-sown rice-vetch cropping system. In order to improve the survival of vetch plants, vetch seeds should germinate from the heading .stage to before the full-ripening stage of rice plants. To enhance the percent of over-wintering survival, vetch seeds should germinate no later than the end of October in southern Korea. The dry weight of vetch plants increased with the progress of vetch growth until the flowering stage but N content decreased for 30 days from before the flowering stage (2.9%) until the ripening stage (1.8%). We concluded that Chinese milk vetch could have an effect on weed control before the flowering stage, sustainability without re-sowing of seed annually, and effective green manure for rice pre-crop in no-till direct-sown rice-vetch relay cropping systems.

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Effect of Nitrogen Fertilization on Growth, Dry Matter Yield and Nitrogen Use of Orchardgrass (질소기비에 대한 Orchardgrass의 생육 및 수량반응과 질소이용성)

  • 윤진일;이호진
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.26 no.3
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    • pp.257-262
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    • 1981
  • Field experiment with 0, 100, 200, 400, and 800 kg-N/ha-year application levels was carried out to study the nitrogen response in the early stage of orchardgrass pasture establishment at College Fann, SNU, in 1979 and 1980. Both the highest dry matter yield and maximum percent of N recovery were obtained at the same level of 200 kg-N/ha in the year of seeding. but those of the next year were obtained at 400 kg-N/ha level. Leaf area indices (LAI) and net assimilation rates (NAR) during each regrowth periods as well as total nitrogen contents of forage at each cutting time increased with applied N in both years. The maximum crop growth rate (CGR) over two years was estimated to be obtained when LAI reached to about 5. The accumulation of NO_3 -N in forage started from 400kgㆍN/ha application in 1980. and exceeded the safe level for ruminants at the level of 800 kg-N/ha.

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A Study of the Effective Weed Control by Herbicides in a Nursery and Forests(I) -Weed Control in a Nursery for Silviculture and Landscape Architecture- (묘포장 및 산지에서 제초제를 이용한 효과적인 잡초방제에 대한 연구(I) -조림.조경용 수묘포장의의 제초관리-)

  • 서병수;김세천;박종민;이창헌
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.1
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    • pp.29-38
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    • 1999
  • Three kinds of soil surface applied herbicides and three kinds of foliage applied herbicides were used to study weed control effect, appropriate concentration, phyto-toxicity against trees and economical efficiency of weed control on trees, Pinus thunbergii, Picea abies, Chamaecyparis obtusa, Quercus accutissima, and Fraxinus rhynchopylla in a nursery. The results were obtained as follows; 1.The control effect of the soil surface applied herbicides showed that the three herbicides; Alachlor, Pendimenthalin and Simazine were alike in their holding effect of weed development, and the sensibility of weed spp. on the herbicides was different. The mean control effect was 58~89%. 2. The weed control effect of the foliage applied herbicides demonstrated that Paraquat dichloride was the best of 84~95% and followed by Glufosnate ammonium and Glyphosate. Especially when the half of its standard amount was treated, the effect of Paraquat dichloride was higher than the other herbicides. 3. Generally, the weed control effect became better as the concentration of the herbcide getting higher. As the concentration of the herbicide got higher, the restraining effect of weed development was continued for a long time in the soil surface applied herbicides, while the weed control effect appeared earlier in the foliage applied herbicides. 4. As the result of the soil surface treatments, 20% of short seedings of Fraxinus rhychopylla treated with twice amount of standard Alachlor died and the rest seeding showed low growth. In the other treatments, there was neither harmful effect of herbicides on the seedings nor growth decrease of them compared to those weeded by men. 5. When treated with foliage applied herbcides, leaves were partially of and discolorated in most treatments. About 0.4~6.2% of Fraxinus thynchopylla, which had short seedings died, and there was no difference in growth with the other treatments. 6. The herbicides showed better economical efficiency over 68% than weed control by men. Especially, Alachlaor of the soil surface applied herbicides showed the highest efficiency(77.6%), while Paraquat dichloride of the foliage applied herbicides was the best(70.3%)..

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The Treatment of Slurry-type Swine Waste using UASB Reactor (UASB 공정에 의한 슬러리형 돈사폐수의 처리)

  • Won, Chul-Hee;Kim, Byoung-Ug;Han, Dong-Joon;Rim, Jay-Myoung
    • Journal of Korean Society on Water Environment
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    • v.20 no.6
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    • pp.583-588
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    • 2004
  • This research examined the treatment efficiency and methane production rate in treating slurry-type swine waste using UASB (upflow anaerobic sludge blanket) reactor. The UASB reactor was operated at an organics volumetric loading rate (VLR) of $2.6-15.7kgCOD/m^3/day$. A stepwise increase of the VLR resulted in a temporary deterioration in the COD removal rate in UASB reactor but recovered quickly. The COD removal rate were 65-70% for VLR up to $5 kgCOD/m^3/day$. When organics VLR was $10kgCOD/m^3/day$, the COD removal rate decreased sharply and there was loss of 17.537g of the seeding biomass due to sludge washout. This result indicated that the UASB system cannot be adapted to more than $10kgCOD/m^3/day$ of VLR. As the organic load increased from 2.6 to $15.7kgCOD/m^3/d$, the biogas production rate varied from 3.2 to 10.8 L/d and the methane conversion rate of the organic matter varied from 0.30 to $0.23m^3CH_4/kg\;COD_{removed}$. The methane content showed the range of 70.1-81.5% during the experimental period. The volatile solids (VS) removal efficiency was similar at the low VLR (< $5 kgCOD/m^3/day$), but it decreased sharply at the high VLR (> $5 kgCOD/m^3/day$). The VS reduction rate was, moreover, large those of COD. The result shows that hydraulic retention time above 2 days is essential in case of treating wastewater containing 1% of solids.

Biomass Partitioning during Early Growth Stage of Soybean in Response to Planting Time

  • Seong, Rak-Chun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.4
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    • pp.286-291
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    • 2002
  • Seedling establishment of soybean [Glycine max (L.) Merr.] is a critical factor in production system and cultural practices. The objective of this study was to identify the components of soybean seedling developments encompassing planting dates and cultivars that respond to emergence, early growth stage and dry matter accumulation. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted at Baegsan silty loam soil. Planting date was May 13, June 3, and June 24 in 2001. Sprinkler irrigation was accompanied with 30mm after seeding for three planting dates. Soybean seedlings were sampled at the growth stages from VE to V5. Days to emergence of soybean seedlings were taken 8 at May 13 and 5 at June 24 plantings. Emergence percentage was over 90 at three planting dates. May 13 planting took 33 days and June 24 planting was 25 days for reaching V5 growth stage. Cotyledon number was decreased after V2. Significant cultivar difference was found in cotyledon dry weight until V2 which differed in seed dry weights at the planting times. Leaf and total dry weights of soybean seedlings were not differed from V1 to V3 among planting dates and cultivars. Leaf water contents were generally ranged 78 to 85%. Branch was appeared from V4. Leaf/stem ratio among cultivars was similar at five growth stages and gradually increased from 2.1 at V1 to 2.8 at V5. The results based on this experiment indicated that seedling establishment of soybean was continued from VE to V3 growth stages affecting mainly by planting date and soil moisture.

Study on The Water Requirements of Chinese Cabbage. (배추 용수량에 관한 연구)

  • 김현철;정두호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.16 no.2
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    • pp.3430-3437
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    • 1974
  • .It is very importaut to know the water consumption of crops in planning irrigation works and practicing suitable soil moisture management. For the purpose of making it clear that how much water be consumed to cultivate the Chinese cabbage, Chamber method has been applied. Main equipments in the transpiration chamber are flowers, manometer and electric thermograph. The chamber made of vynyl plate has a small entrance at the base and an exit at the top, and the ventilation in the chamber was carried out by a flower through the entrance and exit. Air-flow adjusted by an orifice manometer enters the chamber from the outside over the crop canopy through the pipe like a chimney and finally goes out to the outside. Two sets which consist of a pair of dry and wet bulb made by thermistor are installed in the entrance and exit tube, and record air temperature automatically. Evapotranspiration amount is computed from the air-flow quantity and difference in absolute humidity between at the entrance and exit of the chamber by the following equation: ET=(X2-X1)${\times}$Q where ET=evapotranspiration amount X1=absolute humidity at the entrance(g/㎥) X2=absolute humidity at the exit(g/㎥) Q=air-flow quantity(㎥) This study was carried out at the upland farm of the Institute of Agriculture Engimeering and Utilization, Suwon, Korea. from 1971 to 1973. The results obtained in this experiment are as follows: 1. The total amount of evapotranspiration of Chinese Cabbage that is cultivated in autumn is 408.1mm during growth period. 2. Chinese cabbage rapidly grows up in the second ten days of September, 40th to 50th days after seeding. At the same time, the maximum amount of evaportranspiration of Chinese cabbage is 61.6mm/10 days 3. The correlation between Pan-evaporation and evapotranspiration is high, coefficient of correlation r=0.88**, and can be shown as The following regression equation: ET=0.913E+20.273 4. Evapotranspiration is closely related with meteorological factors: r=0.85**, for insolation, r=0.76** for air temperature, respectively. 5. The percentage of evapotranspiration amount, at the beginning of growth stage, gradually increases in proportion as the Chinese Cabbage grows but is largely affected by meteorological factors after the green cover formation. 6. By Blaney and Griddle formula, evaportranspiration coefficient "K" are within from 0,85 to 1.27.

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Effect of High Water-Swelling Polymer Rate on Seedling Survival of Major Turfgrasses Grown on Soil Organic Amendment Mixtures (토양개량재 혼합구에서 고분자 중합체 비율이 주요 잔디류의 유묘 생존에 미치는 효과)

  • Kim, Kyoung-Nam;Park, So-Hyang
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.14 no.2
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    • pp.21-32
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    • 2011
  • The effects of high polymer on the seedling survival were investigated in three major turfgrasses. Twelve treatments were used in the study with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Turfgrass seedling survival rate was evaluated in creeping bentgrass (CB), Kentucky bluegrass (KB), and zoysiagrass (Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments. Seedling survival rates were variable in CB, KB, and Zoy according to mixing rates of SOA and WSP, being maximum 20.2% in differences. At 6 weeks after seeding, the survival rates ranged from 0.6 to 61.9% in CB, 4.2 to 75.3% in KB and 1.7 to 82.1% in Zoy. A pattern of seedling emergence varied with time among treatments influenced by WSP rates. A proper mixing rate of WSP is considered to be 5% for CB and 5 to 10% for KB and Zoy. In general, overall effect of WSP on seedling survival was clearly observed in the mixtures of sand 80% and SOA 20% in CB. The best result, however, was found from the mixture of sand 85% and SOA 15% in both KB and Zoy. When mixing sand with WSP, a proper rate of SOA is considered to be 20% for CB and 15 to 20% for KB, while 10 to 15% for Zoy. A further research is needed to investigate the effects of WSP on the turf quality in mixtures of sand, SOA, and WSP before a field application.

Growth Characteristics and Yields of 3 Year Old Korean Ginseng with Different Planting Densities in Direct Seeding Cultivation (인삼 직파 3년생에서 재식밀도에 따른 품종별 생육특성)

  • Park, Hong Woo;Jang, In Bae;Kang, Seung Weon;Kim, Young Chang;Kim, Jang Uk;Bang, Kyong Hwan;Kim, Gi Hong;Hyun, Dong Yun;Choi, Jae Eul
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.5
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    • pp.372-379
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    • 2013
  • The present study was investigated the effect of planting density on plant growth and yield of Panax ginseng C. A. Meyer. Sowing density is one of the most important factors affecting yield. The value of roots have affected by shape, color, weight and degree of disease injury in ginseng. Also, it needed to minimize elapsed time for 5 years including pre-planting field management and cultivation period. We were conducted to evaluate that planting densities and varieties on the growth, yield and missing rate. The direct sowing was treated seeds density as a four levels (seeds; 72, 90, 120, 144) and 10 different varieties with 3 years old ginseng roots. Root weight was significantly affected by planting density and variety, but the number of lateral root and yield were affected by only planting density. Growth index was related to variety and planting density. Also, Root shape index was affected by both varieties and planting densities. Suitable planting density and variety were 120 plant per 1.62 $m^2$ and Gopoong, respectively. Results showed that it was also a significant difference (p=5%) in variety of planting density on growth.

Nonenzymatic Sensor Based on a Carbon Fiber Electrode Modified with Boron-Doped Diamond for Detection of Glucose (보론 도핑 다이아몬드로 표면처리된 탄소섬유 기반의 글루코스 검출용 비효소적 바이오센서)

  • Song, Min-Jung
    • Korean Chemical Engineering Research
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    • v.57 no.5
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    • pp.606-610
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    • 2019
  • In this study, we demonstrated that the nonenzymatic glucose sensor based on the flexible carbon fiber bundle electrode with BDD nanocomposites (CF-BDD electrode). As a nano seeding method for the deposition of BDD on flexible carbon fiber, electrostatic self-assembly technique was employed. Surface morphology of BDD coated carbon fiber electrode was observed by scanning electron microscopy. And the electrochemical characteristics were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry. This CF-BDD electrode exhibited a large surface area, a direct electron transfer between the redox species and the electrode surface and a high catalytic activity, resulting in a wider linear range (3.75~50 mM), a faster response time (within 3 s) and a higher sensitivity (388.8 nA/mM) in comparison to a bare CF electrode. As a durable and flexible electrochemical sensing electrode, this brand new CF-BDD scheme has promising advantages on various electrochemical and wearable sensor applications.

Effect of Early Soybean Seeding on Isoflavone Content and Amino Acid Composition (콩 조기파종이 Isoflavone 함량 및 아미노산 조성에 미치는 영향)

  • Jong Hyuk Kim;Mi Ha Jang;Ju Hee Nam;Il Rae Rho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.67 no.4
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    • pp.242-252
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    • 2022
  • Soybeans have various applications, and are a major source of proteins, carbohydrates, and fats. As climate warming has accelerated in recent years, this study was conducted to analyze the effect of different sowing periods on component changes in protein, amino acid, and antioxidant contents of various soybean varieties. The isoflavone content of soybeans that were sown early did not differ with the sowing period. Based on the results, only the total isoflavone content was confirmed in functional soybean cultivars such as Cheongja-5, which had blue-colored seeds; Pungsan and Sowon, which used soybean sprouts; and Jinyang, which lacked a fishy smell. There was no significant difference in the changes in protein and amino acid content in soybean cultivars with respect to the sowing time. The protein and amino acid contents in early-sown soybeans tended to be lower than that in timely sown soybeans. In most varieties, the content of proline was the highest in early-sown soybeans, confirming the presence of stress due to early sowing.