• Korean Journal of Organic Agriculture
• /
• v.23 no.4
• /
• pp.643-658
• /
• 2015

This study presents detailed emission of greenhouse gases of using Clean Energy Agriculture System according to a cradle-to-gate life-cycle assessment, including emission from energy use and leak of Biogas. Calculations were done with the PASS software and the covered gases are $CH_4$, $N_2O$ and $CO_2$, Total GHG fluxes of amount to $1719.03kgCO_2/day$, $39.63kgCO_2/day$ (2.31%) are from facility house process, $0.19kgCO_2/day$ (0.01%) are from transport process, $696.72kgCO_2/day$ (40.53%) are from Anaerobic digestion process, $846.61kgCO_2/day$ (49.25%) are from Heating and cooling system, $135.88kgCO_2/day$ (7.90%) are from Fertigation production process. The results suggest that for effective reduction of GHG emissions from Facility house using clean energy. Reduction targets should address both the production process as defined by IPCC sectors and the consumption process. An LCA assessment as presented here could be a basis for such efforts.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.652-658
• /
• 2013

A huge number of greenhouse soils in Korea have accumulated mineral elements which induce many nutritional and pathological problems. The present study was performed to the effects of the reduced fertilization on plant growth, and uptake and partitioning of minerals (N, P, K) and soluble carbohydrates using highly minerals-accumulated farmer's greenhouse soil. On the basis of the recommended application for tomato crop, the application rates of N, P and K were 110(50%)-5.2(5%)-41.5(35%)kg $ha^{-1}$, respectively, using Hoagland's nutrient solution. Tomato growth rates during the whole experiment were not significant between treatments, but it was found that a decrease in daily growth represented after 60 days of treatment (DAT). The reduced application led to a drastic decrease in the concentration of N, P and K in fruits, and, thus, this resulted in lower uptake after 40 DAT. The lower phloem export and utilization of soluble carbohydrates caused an accumulation of extra-carbohydrates in leaves, stems and fruits in the reduced application. The reduced fertilization induced the capture of N, P and K in leaves and of soluble carbohydrates in stems compared to the conventional application. In this study, we suggest that it is possible to delay the first fertigation time in minerals-accumulated soils without an adverse impact on crop growth, but it is necessary to regularly monitor mineral status in soil to ensure a balanced uptake, synthesis and partitioning of minerals and carbohydrates.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.4
• /
• pp.333-339
• /
• 2009

Various cultural practices have been promoted as management options for enhancing soil quality and health. The use of soil management methods can cause changes in fertility by affecting soil chemical properties. This study aimed to evaluate interactions between soil chemical properties and soil management methods in protected cultivation, and to classify soil management methods that similarly affect soil chemical properties. Water-logging and irrigation reduced soil pH and available $P_2O_5$ content. Application of animal manures has a positive effect on levels of organic matter, Av.$P_2O_5$, K, Zn, and Cu. The electrical conductivites tened to be low in the application of organic amendments, including rice and wood residues. Deeper plowing caused a reduction in Ca content. Practicing soil nutrient-considering fertilization and fertigation did not exert an influence on nutrient element contents. In a cluster analysis of the soil management methods according to major nutrients, low similarities were found with deeper plowing and crop rotation with rice in comparison with other practices. In a cluster analysis by minor nutrient characteristics, crop rotation and application of animal manures and rice residues were linked at a high Ward's distance, while other practices were found to be relatively low distinct. Each soil management method has a similar or different effect on soil chemical properties. These results suggest the necessity of establishing limits and standards according to the effects of soil management methods on soil chemical properties for economic soil practices.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.319-324
• /
• 2015

An estimation of the requirement of minerals based on growth stage and cropping pattern is very important for greenhouse zucchini. This study was performed at farmer's field which was applied with a fertigation system and a semi-forcing cultivation from Feb. to July in 2014, and nitrogen levels were set up with x0.5, x0.75, x1.0 and x1.5 of the NO3-N-based soil-testing recommendation for zucchini cultivation. Top dressing of nitrogen (basal : top = 4 : 6) and potassium (basal : top = 3 : 7) was applied with an interval of every two weeks from two and six weeks after transplanting, respectively, and phosphorus was totally supplied with basal dressing. The nitrogen uptake was the order of x1.0, x0.75, x1.5 and x0.5, phosphorus, x1.0, x0.75, x0.5 and x1.5, and potassium, x0.75, x1.0, x1.5 and x0.5. From these results, it was suggested that highest mineral uptake could be reached between x0.75 and x1.0 of the NO3-N-based soil-testing recommendation. In conclusion, nutrient management based on the growth stage was proven to be better method for favorable growth and yield of zucchini.

• Food Science and Preservation
• /
• v.16 no.5
• /
• pp.675-679
• /
• 2009

We investigated how Germanium (Ge) application, and the application method, affected 'Niitaka' (Pyrus pyrifolia) fruit quality in a conventional orchard. Ge-treated pears weredark yellow in color, indicating appropriate maturation. Other fruit characteristics, and weight, did not significantly differ between tests and controls. Compared to controls, fruit from Ge-treated trees had more soluble solids, a lower acid content, and fewer stone cells, which reduced fruit chewiness. Ge-treated trees showed a higher Ge concentration in fruit but a lower calcium (Ca) concentration. Other fruit mineral nutrients, includingP, K, and Mg, did not differ in level between Ge-treated fruit and controls. Ge-treated fruit showed greater firmness and a heavier specific weight during 6 months of storage, compared to control fruit. Therefore, Ge treatment reduced fruit pithiness, which can be a problem in 'Niitaka' pears. Overall, there was no significant difference between Ge-treated and control fruit qualities, but a combined Ge treatment (fertilization plus foliar application plus trunk injection) slightly improved fruit quality.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.53-53
• /
• 2020

가뭄이 매년 지속됨에 따라 고랭지배추 재배지에서도 관수의 필요성이 인식되면서 관수를 실시하고 있으며, 대부분 스프링클러로 관수하고, 분수호스나 점적호스도 일부 이용하고 있으나 아직 토양수분, 토성이나 작물상태, 재배시기 등 환경요인을 고려한 과학적인 수분관리가 이루어지지 못하고 있어 고품질 안정생산을 위해서는 수분관리의 과학화가 필요한 실정이다. 물을 최소화 하면서 관비가 가능한 점적 호스 재배는 적정한 비료를 필요한 위치에 공급하는 방식으로 비료의 효율을 높이면서 환경오염을 최소화하고, 비료과다 시용에 따른 환경오염 등을 회피할 수 있는 좋은 수단이다. 본 연구는 앞으로 고랭지배추 점적호스 재배시 가뭄 극복과 효율적인 시비를 위한 적정 관비횟수를 구명하고자 하였다. 배추품종은 수호를 이용하였으며 관비횟수는 2회(20일 간격), 3회(15일), 4회(10일), 6회(7일), 관행(추비3회) 등 5처리를 두었으며 기준시비량은 N-P-K=32.0-7.8-19.8kg/10a로 하였으며 관비농도는 EC 1.2 dS/m fh 하였다. 시험은 고령지농업연구소 시험포장에서 6월 하순부터 8월 상순까지 무멀칭 노지재배를 하였다. 관비는 정식후 7일째부터 주었으며 관비량은 1회 구당 20ℓ를 주었다. 시험구배치는 단구제 3반복으로 배치하였다. 생육시기별로 초장, 엽장, 엽폭 모두 관비횟수가 많은 처리에서 생육이 좋았으며 6회 처리가 가장 생육이 좋았다. 주당 외엽수와 내엽수는 관행보다는 관비횟수가 많을수록 많아져 관비 6회에서 주당 69.7매로 가장 많았으며 주중과 구중도 관행에 비해 관수횟수가 많아질수록 높아졌으며 관비 6회에서 주중은 2,439g, 구중은 1,917g 으로 높게 나타나, 고랭지배추 관비횟수는 EC 1.2 dS/m 농도에서 6회를 한 것이 생육이 양호하였다.

• Korean Journal of Agricultural Science
• /
• v.49 no.4
• /
• pp.871-879
• /
• 2022

An increasing global population requires a greater food supply, and accordingly there is demand for enhanced production of rice, as a major crop plant that covers half of the world's population. Rice production in arid area is extremely difficult due to poor soil fertility, salinity, deficit of irrigation water, and weather conditions. The aim of the present study was to determine whether various fertilization recipes could provide a countermeasure to allow rice production while also providing soil amendment such as soil pH adjustment. The study was conducted at an experimental field of the United Arab-Emirates (UAE) from January to April, 2022. Rice seedlings (cv. Asemi, alkaline-resistant) were transplanted in plastic containers, and different types of water and nutrient managements were employed as follows: water management (flooding and aerobic for NPKs treatment group) and nutrient management (NPKs, slow release fertilizers [SRFs] and SRFs + NPK-1 treatment groups with flooding). Water and nutrient management did not show any effect on soil pH adjustment. Rice growth was significantly enhanced in the flooding compared to the aerobic condition, whereas the effect of nutrient management clearly differed among the treatment groups, with SRFs + NPK-1 showing the best results followed by SRFs and NPKs. Most of the fertilization groups markedly accumulated soluble sugars in the shoots and grains of rice plants, but concomitantly a decrease in the roots. Overall, the level of starch showed a tendency of relatively slight perturbation by fertilization. Taken together, the results indicate that soil physical structure should be preferentially amended to find the key for suitable rice production.

• Korean Journal of Agricultural Science
• /
• v.36 no.2
• /
• pp.135-145
• /
• 2009

This research was conducted to investigate the effect of various phosphorus concentrations in fertilizer solution on growth of and nutrient uptake by 'Chugyang' egg plant (Solanum melongena L.). Tissue and soil analyses were also conducted to set the threshold levels of phosphorus in plants when disorders develop for phosphorus deficiency or excess. Brown and purple areas developed on the margin of mature leaves and it enlarged rapidly in P deficient plants. The fruits in P deficient plants were small and dull purple in color. When P were excess in fertigation solution, the margins of lower leaves became scorched and it enlarged to inner part of the leaves. The fruits of P excess plants became small and had the curl shape. The tissue $PO_4$-P contents in the most recently fully expanded leaves and dry weight of full above ground plant tissue at 35 days after transplanting showed quadratic response ($y=0.7887+0.2394x-0.0197x^2$) and cubic response ($y=10.43+14.47x-4.7642x^2+0.3977x^3$) to elevated $PO_4$-P concentrations, respectively. When 10% reduction in dry weight set to threshold levels, optimum tissue $PO_4$-P contents are between 0.98 to 1.35%. The yield determined at 150 days after transplanting also showed cubic response to elevated phosphorus concentrations in fertigation solution ($y=1194.6+1502.2x-454.5x^2+35.64x^3$). When the 10% reduction in yield is set to threshold levels, the tissue $PO_4$-P contents for maximum yield should be around 1.53% to 2.25% in most recently fully expanded leaves at 150 days after transplanting.

• Journal of Bio-Environment Control
• /
• v.21 no.3
• /
• pp.163-169
• /
• 2012

We have conducted three experiments to develop a fertilizer-dissolving apparatus used in fertigation or hydroponics cultivation in order to decrease the fertilizer dissolving time and labor input via automation. All of the experiments were conducted twice. In the first experiment, four selected treatments were tested to dissolve fertilizers rapidly. The first treatment was to dissolve fertilizer by spraying water with a submerged water pump, placed in the nutrient solution tank. The water was sprayed onto fertilizer, which is dissolved and filtered through the hemp cloth mounted on the upper part of the nutrient solution tank (Spray). The second treatment was to install a propeller on the bottom of the nutrient solution tank (Propeller). The third treatment was to produce a water stream with a submerged water pump, located at the bottom of the tank (Submerged). Finally, the fourth treatment was to produce an air stream through air pipes with an air compressor located at the bottom of the tank (Airflow). The Spray treatment was found to take the shortest time to dissolve fertilizer, yet it was inconvenient to implement and manage after installation. The Airflow treatment was thought to be the best method in terms of the time to dissolve, labor input, and automation. In the second experiment, Airflow treatment was investigated in more detail. In order to determine the optimal number of air pipe arms and their specification, different versions of 6- and 8-arm air pipe systems were evaluated. The apparatus with 6 arms (Arm-6) that was made of light density polyethylene was determined to be the best system, evaluated on its time to dissolve fertilizer, easiness to use regardless of the lid size of the tank, and easiness to produce and install. In the third experiment, the Submerged and Arm-6 treatments were compared for their dissolving time and economics. Arm-6 treatment decreased the dissolving time by 8 times and proved to be very economic. In addition, dissolving characteristics were investigated for $KNO_3$, $Ca(NO_3)_2{\cdot}4H_2O$, and Fe-EDTA.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.4
• /
• pp.326-333
• /
• 2005

To enhance groundwater quality and soil nutrient management in fertigated plastic film house, groundwater samples from Jinju 52, Sacheon 3, Changnyeong 3, Sancheong 4 and Namhae 2 sites and soil samples from Jinju 23 sites were collected from September to November in 2004. The average concentration of $NO_3-N$ in groundwater was $12.0mg{\ell}^{-1}$ and 20% of survey sites exceeded the limiting level $(20mg{\ell}^{-1})$ of agricultural goundwater quality. The amount of ions in groundwater was in the order of $Ca^{2+}>Na^+>Mg^{2+}>NH_4-N>K^+$ in cations and ${HCO_3}^->{SO_4}^{2-}>NO_3-N>Cl^-$ in anions. Electrical conductivity of groundwater was positively correlated with $Ca^{2+},\;Cl^-,\;Mg^{2+},\;{SO_4}^{2-},\;NO_3-N\;and\;Na^+$ concentrations. In addition, it had significantly positive correlation with sum cations and anions, respectively $({\Sigma}cations\;(me{\ell}^{-1})$ = EC values $(dS\;m^{-1}){\times}4.65,\;{\Sigma}anions\;(me{\ell}^{-1})$ = EC values $(dS\;m^{-1}){\times}7.63\;and\;{\Sigma}\;(cations+anions,\;me{\ell}^{-1})$ = EC values $(dS\;m^{-1}){\times}11.1)$. The proportions of soil chemical properties over the critical levels for crop production in fertigated plastic film house were 56.5% in pH, 47.8% in OM, 95.7% in available $P_2O_5$, 78.3% in exchangeable K, 87% in exchangeable Ca, 56.5% in exchangeable Mg and 43.5% in EC. Soil pH was positively correlated with pH $(r=0.540^{**})$ and ${HCO_3}^-$ concentration $(r=0.523^{**})$ of groundwater.