• Title/Summary/Keyword: Crop Area

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Estimation of Paddy Rice Growth Parameters Using L, C, X-bands Polarimetric Scatterometer (L, C, X-밴드 다편파 레이더 산란계를 이용한 논 벼 생육인자 추정)

  • Kim, Yi-Hyun;Hong, Suk-Young;Lee, Hoon-Yol
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.31-44
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    • 2009
  • The objective of this study was to measure backscattering coefficients of paddy rice using a L-, C-, and X-band scatterometer system with full polarization and various angles during the rice growth period and to relate backscattering coefficients to rice growth parameters. Radar backscattering measurements of paddy rice field using multifrequency (L, C, and X) and full polarization were conducted at an experimental field located in National Academy of Agricultural Science (NAAS), Suwon, Korea. The scatterometer system consists of dual-polarimetric square horn antennas, HP8720D vector network analyzer ($20\;MHz{\sim}20\;GHz$), RF cables, and a personal computer that controls frequency, polarization and data storage. The backscattering coefficients were calculated by applying radar equation for the measured at incidence angles between $20^{\circ}$ and $60^{\circ}$ with $5^{\circ}$ interval for four polarization (HH, VV, HV, VH), respectively. We measured the temporal variations of backscattering coefficients of the rice crop at L-, C-, X-band during a rice growth period. In three bands, VV-polarized backscattering coefficients were higher than hh-polarized backscattering coefficients during rooting stage (mid-June) and HH-polarized backscattering coefficients were higher than VV-, HV/VH-polarized backscattering coefficients after panicle initiation stage (mid-July). Cross polarized backscattering coefficients in X-band increased towards the heading stage (mid-Aug) and thereafter saturated, again increased near the harvesting season. Backscattering coefficients of range at X-band were lower than that of L-, C-band. HH-, VV-polarized ${\sigma}^{\circ}$ steadily increased toward panicle initiation stage and thereafter decreased, and again increased near the harvesting season. We plotted the relationship between backscattering coefficients with L-, C-, X-band and rice growth parameters. Biomass was correlated with L-band hh-polarization at a large incident angle. LAI (Leaf Area Index) was highly correlated with C-band HH- and cross-polarizations. Grain weight was correlated with backscattering coefficients of X-band VV-polarization at a large incidence angle. X-band was sensitive to grain maturity during the post heading stage.

Estimation of Soybean Growth Using Polarimetric Discrimination Ratio by Radar Scatterometer (레이더 산란계 편파 차이율을 이용한 콩 생육 추정)

  • Kim, Yi-Hyun;Hong, Suk-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.5
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    • pp.878-886
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    • 2011
  • The soybean is one of the oldest cultivated crops in the world. Microwave remote sensing is an important tool because it can penetrate into cloud independent of weather and it can acquire day or night time data. Especially a ground-based polarimetric scatterometer has advantages of monitoring crop conditions continuously with full polarization and different frequencies. In this study, soybean growth parameters and soil moisture were estimated using polarimetric discrimination ratio (PDR) by radar scatterometer. A ground-based polarimetric scatterometer operating at multiple frequencies was used to continuously monitor the soybean growth condition and soil moisture change. It was set up to obtain data automatically every 10 minutes. The temporal trend of the PDR for all bands agreed with the soybean growth data such as fresh weight, Leaf Area Index, Vegetation Water Content, plant height; i.e., increased until about DOY 271 and decreased afterward. Soil moisture lowly related with PDR in all bands during whole growth stage. In contrast, PDR is relative correlated with soil moisture during below LAI 2. We also analyzed the relationship between the PDR of each band and growth data. It was found that L-band PDR is the most correlated with fresh weight (r=0.96), LAI (r=0.91), vegetation water content (r=0.94) and soil moisture (r=0.86). In addition, the relationship between C-, X-band PDR and growth data were moderately correlated ($r{\geq}0.83$) with the exception of the soil moisture. Based on the analysis of the relation between the PDR at L, C, X-band and soybean growth parameters, we predicted the growth parameters and soil moisture using L-band PDR. Overall good agreement has been observed between retrieved growth data and observed growth data. Results from this study show that PDR appear effective to estimate soybean growth parameters and soil moisture.

Assessment of Nutrient Losses in Different Slope Highland Soils Amended with Livestock Manure Compost (경사도와 축분 부산물비료 시용에 따른 고랭지 밭의 양분 유실량)

  • Joo, Jin-Ho;Lee, Seung-Been
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.3
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    • pp.361-367
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    • 2011
  • Soil fertility of alpine soils in Gangwon-Do has been deteriorating because of heavy input of chemical fertilizers for intensive crop production. To reduce application of chemical fertilizers, use of livestock manure compost in alpine soils increases consistently. Soil loss and runoff due to heavy rainfall in alpine area cause nutrient loss from soil, and subsequently pollute stream water. Therefore, the objective of this study was to assess nutrient efficiency and loss in Chinese cabbage cultivated soil with different livestock manure composts in several slopes. As control, chemical fertilizer was applied at the rate of $250-78-168kg\;ha^{-1}$ for $N-P_2O_5-K_2O$. Each pig-and chicken manure compost was applied at the rate of $10MT\;ha^{-1}$. Chemical fertilizer + chicken manure compost was applied as same rate. Four treatments was practiced in 5, 20, and 35% filed slopes, respectively. We monitored the amounts of soil loss and runoff water after rainfalls, and we also analyzed the contents of nutrients in soil and runoff water through lysimeter installed in alpine agricultural institute in Gangwon-Do. T-N loss due to soil loss was much greater with increasing filed slops rather than different fertilizer treatments. T-N loss has positive relationship with field slopes, which showing soil loss (MT/ha) = 1.66 slopes (%) - 3.5 ($r^2$ = 0.99). Available phosphate and exchangeable cations showed similar tendency with increasing slopes. T-N and T-P losses caused by runoff water were highest in chemical fertilizer (NPK) + chicken manure compost treated plot, while lowest in chemical fertilizer treatment. T-N contents (2.13, 1.95%) in chinese cabbage treated either pig and chicken manure composts compared to that (2.65%) of chemical fertilizer were significantly less. This could be resulted from much greater T-N loss in soil treated with pig and chicken manure composts.

Risk Assessment of As, Cd, Cu and Pb in Different Rice Varieties Grown on the Contaminated Paddy Soil (중금속 오염 논토양에서 재배된 벼 품종간 위해성평가 비교)

  • Kim, Won-Il;Kim, Jin-Kyoung;Yoo, Ji-Hyock;Paik, Min-Kyoung;Park, Sang-Won;Kwon, Oh-Kyung;Hong, Moo-Ki;Yang, Jay-E;Kim, Jeong-Gyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.1
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    • pp.53-57
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    • 2009
  • Heavy metal pollution may be one of the most serious challenges confront crop production and human health. Therefore, the selection of heavy metal tolerance cultivars which adapted to the contaminated fields will introduced a suitable solution for management this critical environmental risk. The objectives of this research is to assess human health risk using geochemical analyses and exposure assessment of heavy metals in rice cultivars. Risk for inhabitants in the closed mine area was comparatively assessed for As, Cd, Cu and Pb in 10 rice varieties as a major exposure pathway. The average daily dose (ADD) of each heavy metal was estimated by analyzing the exposure pathways to rice and soil. For the non-carcinogenic risk characterization, Hazard Quotient (HQ) and Hazard Index (HI) were calculated using toxicity indices provided by US-EPA IRIS. The different rice varieties revealed a wide range of HI values from 23.6 to 34.3, indicating that all rice varieties have a high potential toxic risk. The DA rice variety showed the lowest HI value while the TB rice variety the highest. The probabilities of cancer risk for As via rice consumption were varied with rice varieties ranging from 2.0E-03 to 3.5E-03 which exceeded the regulatory acceptable risk of 1 in 10,000 set by US-EPA. The DA rice variety also showed the lowest value while the TB rice variety gave the highest value. Our results indicate that risk assessment can be contribute to screen the pollution safe rice cultivars in paddy fields affected by the mining activity.

Growth and Flower Bud Induction in Strawberry 'Sulhyang' Runner Plant as Affected by Exogenous Application of Benzyladenine, Gibberellic Acid, and Salicylic Acid (벤질아데닌, 지베렐린산, 살리실산이 '설향' 딸기묘의 생장과 화아 유도에 미치는 영향)

  • Thi, Luc The;Nguyen, Quan Hoang;Park, Yoo Gyeong;Jeong, Byoung Ryong
    • Journal of Bio-Environment Control
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    • v.28 no.2
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    • pp.178-184
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    • 2019
  • Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

Changes in Inorganic Element Concentrations in Leaves, Supplied and Drained Nutrient Solution according to Fruiting Node during Semi-forcing Hydroponic Cultivation of 'Bonus' Tomato ('Bonus' 토마토 반촉성 수경재배 시 착과절위에 따른 식물체, 공급액 및 배액의 무기성분 농도 변화)

  • Lee, Eun Mo;Park, Sang Kyu;Lee, Bong Chun;Lee, Hee Chul;Kim, Hak Hun;Yun, Yeo Uk;Park, Soo Bok;Chung, Sun Ok;Choi, Jong Myung
    • Journal of Bio-Environment Control
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    • v.28 no.1
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    • pp.38-45
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    • 2019
  • Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of 'Bonus' tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in $NO_3-N$, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato.

Effects of Heating Initiative Temperature and CO2 Fertilizing Concentration on the Growth and Yield of Summer Squash in a Greenhouse (온실 난방 개시온도와 CO2 시비 농도가 애호박의 생육과 수량에 미치는 영향)

  • Goo, Hei Woong;Kim, Eun Ji;Na, Hae Yeong;Park, Kyoung Sub
    • Journal of Bio-Environment Control
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    • v.31 no.4
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    • pp.468-475
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    • 2022
  • This study was conducted to find out the efficiency of heating initiative temperature and carbon dioxide fertilization in summer squash (Cucurbita moschata D.). The heating start temperature experiment was performed at 9℃, 12℃, and 15℃ using an electric heater and operated when the temperature was lower than the target temperature. The CO2 fertilization concentration experiment was performed from 7 to 12 with the control, 500 µmol·mol-1, and 800 µmol·mol-1 using liquefied carbon dioxide. Investigation items were plant height, stem diameter, number of leaves, leaf area, fresh weight, dry weight, also economic analysis was conducted by surveying only fruits exceeding 100 g. Photosynthesis was measured for the upper leaf position to calculate the saturation point according to the control. The photo saturation point was 587 µmol·m-2·s-1, and the CO2 saturation point was 702 µmol·mol-1. Amax values by carbon dioxide were 13.4, 17.8, 17.2, 19.6, and 17.5 µmolCO2·m-2·s-1 in the order of 9℃, 12℃, 15℃, 500 µmol·mol-1, and 800 µmol·mol-1. In the temperature experiment, 9℃ in growth did not grow normally and no fruiting was performed. 12℃ and 15℃ were higher than 9℃, but there was no significant difference in growth and production. The CO2 fertilization experiment showed no significant difference between the treatment in growth, but the productivity of 800 µmol·mol-1 was the best. Comprehensively, the heating initiative temperature of 15℃ was good for crop growth and production, but there is no significant difference from 12℃, so it is good to set the heating start temperature to 12℃ economically, and maintaining of 800 µmol·mol-1 is effective in increasing production.

Analysis of Effect on Pesticide Drift Reduction of Prevention Plants Using Spray Drift Tunnel (비산 챔버를 활용한 차단 식물의 비산 저감 효과 분석)

  • Jinseon Park;Se-Yeon Lee;Lak-Yeong Choi;Se-woon Hong
    • Journal of Bio-Environment Control
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    • v.32 no.2
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    • pp.106-114
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    • 2023
  • With rising concerns about pesticide spray drift by aerial application, this study attempt to evaluate aerodynamic property and collection efficiency of spray drift according to the leaf area index (LAI) of crop for preventing undesirable pesticide contamination by the spray-drift tunnel experiment. The collection efficiency of the plant with 'Low' LAI was measured at 16.13% at a wind speed of 1 m·s-1. As the wind speed increased to 2 m·s-1, the collection efficiency of plant with the same LAI level increased 1.80 times higher to 29.06%. For the 'Medium' level LAI, the collection efficiency was 24.42% and 43.06% at wind speed of 1 m·s-1 and 2 m·s-1, respectively. For the 'High' level LAI, it also increased 1.24 times higher as the wind speed increased. The measured results indicated that the collection of spray droplets by leaves were increased with LAI and wind speed. This also implied that dense leaves would have more advantages for preventing the drift of airborne spray droplets. Aerodynamic properties also tended to increase as the LAI increased, and the regression analysis of quadric equation and power law equation showed high explanatory of 0.96-0.99.

Comparative Study on the Carbon Stock Changes Measurement Methodologies of Perennial Woody Crops-focusing on Overseas Cases (다년생 목본작물의 탄소축적 변화량 산정방법론 비교 연구-해외사례를 중심으로)

  • Hae-In Lee;Yong-Ju Lee;Kyeong-Hak Lee;Chang-Bae Lee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.4
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    • pp.258-266
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    • 2023
  • This study analyzed methodologies for estimating carbon stocks of perennial woody crops and the research cases in overseas countries. As a result, we found that Australia, Bulgaria, Canada, and Japan are using the stock-difference method, while Austria, Denmark, and Germany are estimating the change in the carbon stock based on the gain-loss method. In some overseas countries, the researches were conducted on estimating the carbon stock change using image data as tier 3 phase beyond the research developing country-specific factors as tier 2 phase. In South Korea, convergence studies as the third stage were conducted in forestry field, but advanced research in the agricultural field is at the beginning stage. Based on these results, we suggest directions for the following four future researches: 1) securing national-specific factors related to emissions and removals in the agricultural field through the development of allometric equation and carbon conversion factors for perennial woody crops to improve the completeness of emission and removals statistics, 2) implementing policy studies on the cultivation area calculation refinement with fruit tree-biomass-based maturity, 3) developing a more advanced estimation technique for perennial woody crops in the agricultural sector using allometric equation and remote sensing techniques based on the agricultural and forestry satellite scheduled to be launched in 2025, and to establish a matrix and monitoring system for perennial woody crop cultivation areas in the agricultural sector, Lastly, 4) estimating soil carbon stocks change, which is currently estimated by treating all agricultural areas as one, by sub-land classification to implement a dynamic carbon cycle model. This study suggests a detailed guideline and advanced methods of carbon stock change calculation for perennial woody crops, which supports 2050 Carbon Neutral Strategy of Ministry of Agriculture, Food, and Rural Affairs and activate related research in agricultural sector.

A Study on Heterogeneous Catalysts for Transesterification of Nepalese Jatropha Oil (네팔산 Jatropha 오일의 전이에스테르화 반응용 불균일계 촉매 연구)

  • Youngbin Kim;Seunghee Lee;Minseok Sim;Yehee Kim;Rajendra Joshi;Jong-Ki Jeon
    • Clean Technology
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    • v.30 no.1
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    • pp.47-54
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    • 2024
  • Jatropha oil extracted from the seeds of Nepalese Jatropha curcas, a non-edible crop, was used as a raw material and converted to biodiesel through a two-step process consisting of an esterification reaction and a transesterification reaction. Amberlyst-15 catalyst was applied to the esterification reaction between the free fatty acids contained in the Jatropha oil and methanol. The acid value of the Jatropha oil could be lowered from 11.0 to 0.26 mgKOH/g through esterification. Biodiesel was synthesized through a transesterification reaction between Jatropha oil with an acid value of 0.26 mgKOH/g and methanol over NaOH/γ-Al2O3 catalysts. As the loading amount of NaOH increased from 3 to 25 wt%, the specific surface area decreased from 129 to 28 m2/g and the pore volume decreased from 0.249 to 0.129 cm3/g. The amount and intensity of base sites over the NaOH/γ-Al2O3 catalysts increased simultaneously with the NaOH loading amount. It was confirmed that the optimal NaOH loading amount for the NaOH/γ-Al2O3 catalyst was 12 wt%. The optimal temperature for the transesterification reaction of Jatropha oil using the NaOH/γ-Al2O3 catalyst was selected to be 65 ℃. In the transesterification reaction of Jatropha oil using the NaOH/γ-Al2O3 catalyst, the reaction rate was affected by external diffusion limitation when the stirring speed was below 150 RPM, however the external diffusion limitation was negligible at higher stirring speeds.