• Title/Summary/Keyword: The improved soil

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Changes in Growing Period and Productivity under Double Cropping of Spring Potato and Summer Cereals in Paddy Fields of Southern Korea (남부지역 논에서 봄감자와 하작물 이모작에 따른 생육기간 및 생산성 변화)

  • Seo, Jong-Ho;Hwang, Chung-Dong;Choi, Weon-Young;Bae, Hyeon-Kyung;Kim, Sang-Yeol;Oh, Seong-Hwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.64 no.4
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    • pp.459-468
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    • 2019
  • Changes in growing periods and productivities of crops under double cropping of potato-rice, potato-soybean and potato-maize, were investigated at the Paddy Experimental Fields in Miryang City from 2015 to 2018. Spring potatoes planted in early March showed a yield of 2.1-2.3 ton/10a and a period of 90 days. In double cropping, growing period of rice, soybean, and maize was about 130, 125 and 115 days, respectively. The potato yield obtained was as much as 616, 330 and 815 kg/10a under double cropping with rice, soybean and maize, respectively. It is beneficial to sow the spring potatoes as early as possible to increase the yield and to secure the growing period of sequential crops. The introduction of summer medium-late variety grain crops into double cropping of spring potato and rice as well as into double cropping of spring potato and soybean/maize, was possible because of no sowing in the fall and plants were able to reach the heading growth stage before the safe heading limit of rice in particular. In the case of maize, the growth period was different according to the change in temperature over the year. The introduction of upland crops such as soybeans and maize instead of rice improved soil physicochemical properties in a short period of time, contributing to the increase of spring potato yields, but there was also a risk of damage by successive cropping for more than three years. Spring potato-maize showed higher yield in terms of starch production, and spring potato-soybean was found to be advantageous for net income.

Recent Changes in Bloom Dates of Robinia pseudoacacia and Bloom Date Predictions Using a Process-Based Model in South Korea (최근 12년간 아까시나무 만개일의 변화와 과정기반모형을 활용한 지역별 만개일 예측)

  • Kim, Sukyung;Kim, Tae Kyung;Yoon, Sukhee;Jang, Keunchang;Lim, Hyemin;Lee, Wi Young;Won, Myoungsoo;Lim, Jong-Hwan;Kim, Hyun Seok
    • Journal of Korean Society of Forest Science
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    • v.110 no.3
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    • pp.322-340
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    • 2021
  • Due to climate change and its consequential spring temperature rise, flowering time of Robinia pseudoacacia has advanced and a simultaneous blooming phenomenon occurred in different regions in South Korea. These changes in flowering time became a major crisis in the domestic beekeeping industry and the demand for accurate prediction of flowering time for R. pseudoacacia is increasing. In this study, we developed and compared performance of four different models predicting flowering time of R. pseudoacacia for the entire country: a Single Model for the country (SM), Modified Single Model (MSM) using correction factors derived from SM, Group Model (GM) estimating parameters for each region, and Local Model (LM) estimating parameters for each site. To achieve this goal, the bloom date data observed at 26 points across the country for the past 12 years (2006-2017) and daily temperature data were used. As a result, bloom dates for the north central region, where spring temperature increase was more than two-fold higher than southern regions, have advanced and the differences compared with the southwest region decreased by 0.7098 days per year (p-value=0.0417). Model comparisons showed MSM and LM performed better than the other models, as shown by 24% and 15% lower RMSE than SM, respectively. Furthermore, validation with 16 additional sites for 4 years revealed co-krigging of LM showed better performance than expansion of MSM for the entire nation (RMSE: p-value=0.0118, Bias: p-value=0.0471). This study improved predictions of bloom dates for R. pseudoacacia and proposed methods for reliable expansion to the entire nation.

Improvement of a Tree Cutting Permit System with Respect to Timber Logger's Consciousness (벌채업 관련자의 의식 조사를 통한 현행 벌채제도의 개선)

  • Park, Kyung-Seok;Lee, Seong-Youn;Choi, In-Hwa;Kim, Hyun-Sig;Ahn, Young-Sang;An, Ki-Wan
    • Journal of Korean Society of Forest Science
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    • v.101 no.4
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    • pp.710-721
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    • 2012
  • This study is to find out the search of the desirable tree cutting permit system by investigating and analyzing timber logger's consciousness in Korea. A sample group, including 64 officers in 5 Regional Forest Services and 27 National Forest Stations, 161 local government of 322 officers and team leaders with cutting permits, and 308 tree loggers was surveyed. The survey results showed that the ongoing harvest year plan for national, public and private-type forests, which was applied differently, could be integrated as 3.73 points, which was not significant among the groups. A total of 95.1% of the national forest officers stated that the environmentally friendly harvesting system could be improved and that it is exempted from bad broadleaf trees and renewal of forest type (4.14 points). An environmentally friendly harvesting system including the type of forest and location status (slide, soil, etc) is needed (3.87 points). Additionally, the round timber purchased from tree loggers managed in 2009 was about 10.6% of the domestic timber supply ($3,176,000m^3$) and round timber sales were about 50.1%. A total of 72% of the loggers suggested that a environmentally friendly harvesting system is needed (4.11 points). These results show that a new system for harvesting timber is needed to replace the current environmentally unfriendly harvesting system, and that tree loggers should be registered for management.

Yongdam Dam Watershed Flood Simulation Using GPM Satellite Data and KIMSTORM2 Distributed Storm Runoff Model (GPM위성 강우자료와 KIMSTORM2 분포형 유출모형을 이용한 용담댐 유역 홍수모의)

  • KIM, Se-Hoon;KIM, Jin-Uk;CHUNG, Jee-Hun;KIM, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.39-58
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    • 2019
  • This study performed the dam watershed storm runoff modeling using GPM(Global Precipitation Measurement) satellite rain and KIMSTORM2(KIneMatic wave STOrm Runoff Model 2) distributed model. For YongdamDam watershed(930㎢), three heavy rain events of 25th August 2014, 11th September 2017, and 26th June 2018 were selected and tested for 4 cases of spatial rainfalls such as (a) Kriging interpolated data using ground observed data at 7 stations, (b) original GPM data, (c) GPM corrected by CM(Conditional Merging), and GPM corrected by GDA(Geographical Differential Analysis). For the 4 kinds of data(Kriging, GPM, CM-GPM, and GDA-GPM), the KIMSTORM2 was calibrated respectively using the observed flood discharges at 3 water level gauge stations(Cheoncheon, Donghyang, and Yongdam) with parameters of initial soil moisture contents, stream Manning's roughness coefficient, and effective hydraulic conductivity. The total average Nash-Sutcliffe efficiency(NSE) for the 3 events and 3 stations was 0.94, 0.90, 0.94, and 0.94, determination coefficient(R2) was 0.96, 0.92, 0.97 and 0.96, the volume conservation index(VCI) was 1.03, 1.01, 1.03 and 1.02 for Kriging, GPM, CM-GPM, and GDA-GPM applications respectively. The CM-GPM and GDA-GPM showed better results than the original GPM application for peak runoff and runoff volume simulations, and they improved NSE, R2, and VCI results.

Global Ocean Data Assimilation and Prediction System in KMA: Description and Assessment (기상청 전지구 해양자료동화시스템(GODAPS): 개요 및 검증)

  • Chang, Pil-Hun;Hwang, Seung-On;Choo, Sung-Ho;Lee, Johan;Lee, Sang-Min;Boo, Kyung-On
    • Atmosphere
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    • v.31 no.2
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    • pp.229-240
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    • 2021
  • The Global Ocean Data Assimilation and Prediction System (GODAPS) in operation at the KMA (Korea Meteorological Administration) is introduced. GODAPS consists of ocean model, ice model, and 3-d variational ocean data assimilation system. GODAPS assimilates conventional and satellite observations for sea surface temperature and height, observations of sea-ice concentration, as well as temperature and salinity profiles for the ocean using a 24-hour data assimilation window. It finally produces ocean analysis fields with a resolution of 0.25 ORCA (tripolar) grid and 75-layer in depth. This analysis is used for providing a boundary condition for the atmospheric model of the KMA Global Seasonal Forecasting System version 5 (GloSea5) in addition to monitoring on the global ocean and ice. For the purpose of evaluating the quality of ocean analysis produced by GODAPS, a one-year data assimilation experiment was performed. Assimilation of global observing system in GODAPS results in producing improved analysis and forecast fields with reduced error in terms of RMSE of innovation and analysis increment. In addition, comparison with an unassimilated experiment shows a mostly positive impact, especially over the region with large oceanic variability.

Effect of Mixture Rate of Used Media and Perlite on Physico-Chemical of Properties Root Media and Seedling Quality in Fruit Vegetables Plug Nursery System (공정육묘시 재활용 상토에 신규상토 및 펄라이트의 혼합비율이 상토의 이화학적 특성과 과채류 묘소질에 미치는 영향)

  • Byun, Hyo-Jeung;Kim, Young Shik;Kang, Ho-Min;Kim, Il Seop
    • Journal of Bio-Environment Control
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    • v.21 no.3
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    • pp.213-219
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    • 2012
  • Improving the physico-chemical properties of used media by mixing ratio of new plug media (NPM), used plug media (UPM) and perlite is necessary to improve seedling quality. In this study, five treatments were designed to investigate mixing ratio of UPM and NPM by ratio of volume 0 : 100, 25 : 75, 50 : 50, 75 : 25, 100 : 0, respectively. On the other hand, nine treatments were designed to investigate of perlite volumes were added to UPM and mixed media (UPM : NPM (50 : 50)) with 0, 5, 10, and 20% of ratio volume. The physicochemical properties of all mediums and their effect on growth response of tomato and cucumber seedlings were determined. The result indicates that physical properties was improved when NPM was mixed with UPM and at mixed ratio of volume 50 : 50 (v : v) has similar pore spare, bulk density and water retention to NPM. Seedling quality of tomato and cucumber in mixed media (50 : 50) are better than other mixed ratio and similar to NPM. Addition perlite to UPM and mixed media 50 : 50 (v : v) increased the pore space and water retention. Physical properties such as particle density, pore space and bulk density were increased when perlite volume increased. However, the best of seedling quality was observed by the addition at 10% volume of perlite. These results suggested that optimum of mixed ratio for recycled used media is new media and used media 1 : 1 mixed.

Study of Nutrient Uptake and Physiological Characteristics of Rice by $^{15}N$ and Purified Si Fertilization Level in a Transplanted Pot Experiment (중질소와 순수규산 시비수준이 벼의 양분흡수 및 생리적 특성에 미치는 영향)

  • Cho Young-Son;Jeon Won-Tae;Park Chang-Young;Park Ki-Do;Kang Ui-Gum
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.5
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    • pp.408-419
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    • 2006
  • A pot experiment was conducted for two years to evaluate the effects of purified Si fertilization combined with $^{15}N$ on the nutrient uptake, plant growth characteristics, and photosynthetic characteristics of rice in water melon cultivated soil. In 2002, plant height was positively affected at 25 DAT (Day After Transplanting) by Si fertilization in 100%N treatment. However, in 2003, plant height at 25 DAT was negatively affected by Si fertilization in low N level but it was reversed in high N level with initial increase of plant height. Tiller number per pot was positively affected by N and Si fertilization level, especially for high N fertilized treatment. Leaf color was positively affected by Si fertilizatlon in no N fertilized pots, however, Si was not effected in 50%N and 100%N fertilized treatments. N harvest index (NHI) increased with increased Si fertilization in no N plots, however it decreased with increasing of N fertilization level. Nitrogen use efficiency (NUE) decreased with increasing of fertilized N but Si fertilization increased NUE in 50%N plots, however, it was not different by the Si fertilization level in 100%N plots. In 50%N+200%Si plots, NUE was greatest with 130 and shoot N content was $16.2g-N/m^{2}$. N content ($g/m^{2}$) in rice plant increased with increasing Si fertilization in no N plots at panicle initiation stage, 50 and 100%N plots at heading stage and all N treatment at harvesting time. This was mostly more efficient in late growth stage than early growth stage. The concentration (%) of P and K increased with increasing N fertilization level at heading and harvesting but it was not significantly different by the Si fertilization treatment except a little decreasing with increasing Si fertilization level at heading. Potassium content was also not significantly related with N fertilization level except increasing with Si fertilization level at panicle initiation stage. Plant Ca content (%) decreased with increasing of Si fertilization at heading stage and Si fertilization increased Ca content at panicle initiation stage and heading stage and it increased with increasing of Si fertilization level. Photosynthetic activity was not directly related with Si fertilization amount, however, Fluorescent factors, Fv'/Fm' and PsII, were positively affected by Si fertilization level. In conclusion, N fertilization in Si 200% fertilized condition should be reduced by about 50% level of recommended N fertilization for rice cropping in green-house water-melon cultivated paddy field. However, improvement of Ps by Si fertilization could not be attributed to Ps activity in the same leaf area but because of increased total leaf area per pot improved fluorescent characteristics.

Conclusion of Conventions on Compensation for Damage Caused by Aircraft in Flight to Third Parties (항공운항 시 제3자 피해 배상 관련 협약 채택 -그 혁신적 내용과 배경 고찰-)

  • Park, Won-Hwa
    • The Korean Journal of Air & Space Law and Policy
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    • v.24 no.1
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    • pp.35-58
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    • 2009
  • A treaty that governs the compensation on damage caused by aircraft to the third parties on surface was first adopted in Rome in 1933, but without support from the international aviation community it was replaced by another convention adopted again in Rome in 1952. Despite the increase of the compensation amount and some improvements to the old version, the Rome Convention 1952 with 49 State parties as of today is not considered universally accepted. Neither is the Montreal Protocol 1978 amending the Rome Convention 1952, with only 12 State parties excluding major aviation powers like USA, Japan, UK, and Germany. Consequently, it is mostly the local laws that apply to the compensation case of surface damage caused by the aircraft, contrary to the intention of those countries and people who involved themselves in the drafting of the early conventions on surface damage. The terrorist attacks 9/11 proved that even the strongest power in the world like the USA cannot with ease bear all the damages done to the third parties by the terrorist acts involving aircraft. Accordingly as a matter of urgency, the International Civil Aviation Organization(ICAO) picked up the matter and have it considered among member States for a few years through its Legal Committee before proposing for adoption as a new treaty in the Diplomatic Conference held in Montreal, Canada 20 April to 2 May 2009. Accordingly, two treaties based on the drafts of the Legal Committee were adopted in Montreal by consensus, one on the compensation for general risk damage caused by aircraft, the other one on compensation for damage from acts of unlawful interference involving aircraft. Both Conventions improved the old Convention/Protocol in many aspects. Deleting 'surface' in defining the damage to the third parties in the title and contents of the Conventions is the first improvement because the third party damage is not necessarily limited to surface on the soil and sea of the Earth. Thus Mid-air collision is now the new scope of application. Increasing compensation limit in big gallop is another improvement, so is the inclusion of the mental injury accompanied by bodily injury as the damage to be compensated. In fact, jurisprudence in recent years for cases of passengers in aircraft accident holds aircraft operators to be liable to such mental injuries. However, "Terror Convention" involving unlawful interference of aircraft has some unique provisions of innovation and others. While establishing the International Civil Aviation Compensation Fund to supplement, when necessary, the damages that exceed the limit to be covered by aircraft operators through insurance taking is an innovation, leaving the fate of the Convention to a State Party, implying in fact the USA, is harming its universality. Furthermore, taking into account the fact that the damage incurred by the terrorist acts, where ever it takes place targeting whichever sector or industry, are the domain of the State responsibility, imposing the burden of compensation resulting from terrorist acts in the air industry on the aircraft operators and passengers/shippers is a source of serious concern for the prospect of the Convention. This is more so when the risks of terrorist acts normally aimed at a few countries because of current international political situation are spread out to many innocent countries without quid pro quo.

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Studies on the Amylase Production by Bacteria (세균(細菌)에 의(依)한 Amylase생산(生産)에 관한 연구(硏究))

  • Park, Yoon-Joong
    • Applied Biological Chemistry
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    • v.13 no.2
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    • pp.153-170
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    • 1970
  • 1. Isolation and identification of amylase-producing bacteria. The powerful strain A-12 and S-8 were respectively isolated from air and soil after screening a large number of amylase-producing bacteria. Their bacterial characteristics have been investigated and it has been found that all characteristics of strain A-12 and S-8 are similar to Bac. subtilis of Bergey's manual except for the acid formation from a few carbohydrates and the citrate utilization, i.e., the strain A-12 shows negative in the citrate utilization, and the acid formation from arabinose and xylose, S-8 shows negative in the acid formation from xylose. 2. Amylase production by Liquid cultures with solid materials. Several conditions for amylase production by strain A-12 in stationary cultures have been studied. The results obtained are as follows. (1) The optimum conditions are:temperature $35^{\circ}C$, initial pH 6.5 to 7.0 and incubation time 3 to 4 days. (2) The amylase production is not affected by the preservation period of the stock cultures. (3) Among the various solid material, the defatted soy bean is found to be the best for t1e amylase production. However, the alkali treatment of the defatted soy bean gives no effect contrary to the cage of defatted rape seed. The addition of soluble starch to the alkali extract of defatted soy bean shows the increased amylase production. (4) Up to 1% addition of ethanol to carbon dificient media gives the improved amylase production, whereas the above effect is not found in the case of carbon rich media. (5) The amylase production can be increased 2.5 times when 10% of defatted soy bean is admixed to cheaply available wheat bran. (6) The excellent effect is found for amylase production when 20% of wheat bran is admixed to defatted dry milk which is a poor medium. The activity is found to be $D^{40^{\circ}}_{30'}$ 7,000(L.S.V. 1,800) in 10% medium. (7) No significant effect is observed due to the addition of various inorganic salts. 3. Amylase production by solid cultures. Several conditions for amylase production by strain A-12 in wheat bran cultures have been studied and the results obtained are as follows. (1) The optimum conditions: are temperature $33^{\circ}C$, incubation lime 2 days, water content added 150 to 175% and the thickness of the medium 1.5cm, The activity is found to be $D^{40^{\circ}}_{30'}$ 36,000(L.S.V. 15,000) (2) No significant effect is found in the case of the additions of various organic and inorganic substances.

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Estimation of Fresh Weight and Leaf Area Index of Soybean (Glycine max) Using Multi-year Spectral Data (다년도 분광 데이터를 이용한 콩의 생체중, 엽면적 지수 추정)

  • Jang, Si-Hyeong;Ryu, Chan-Seok;Kang, Ye-Seong;Park, Jun-Woo;Kim, Tae-Yang;Kang, Kyung-Suk;Park, Min-Jun;Baek, Hyun-Chan;Park, Yu-hyeon;Kang, Dong-woo;Zou, Kunyan;Kim, Min-Cheol;Kwon, Yeon-Ju;Han, Seung-ah;Jun, Tae-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.329-339
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    • 2021
  • Soybeans (Glycine max), one of major upland crops, require precise management of environmental conditions, such as temperature, water, and soil, during cultivation since they are sensitive to environmental changes. Application of spectral technologies that measure the physiological state of crops remotely has great potential for improving quality and productivity of the soybean by estimating yields, physiological stresses, and diseases. In this study, we developed and validated a soybean growth prediction model using multispectral imagery. We conducted a linear regression analysis between vegetation indices and soybean growth data (fresh weight and LAI) obtained at Miryang fields. The linear regression model was validated at Goesan fields. It was found that the model based on green ratio vegetation index (GRVI) had the greatest performance in prediction of fresh weight at the calibration stage (R2=0.74, RMSE=246 g/m2, RE=34.2%). In the validation stage, RMSE and RE of the model were 392 g/m2 and 32%, respectively. The errors of the model differed by cropping system, For example, RMSE and RE of model in single crop fields were 315 g/m2 and 26%, respectively. On the other hand, the model had greater values of RMSE (381 g/m2) and RE (31%) in double crop fields. As a result of developing models for predicting a fresh weight into two years (2018+2020) with similar accumulated temperature (AT) in three years and a single year (2019) that was different from that AT, the prediction performance of a single year model was better than a two years model. Consequently, compared with those models divided by AT and a three years model, RMSE of a single crop fields were improved by about 29.1%. However, those of double crop fields decreased by about 19.6%. When environmental factors are used along with, spectral data, the reliability of soybean growth prediction can be achieved various environmental conditions.