• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.4
• /
• pp.45-53
• /
• 2013

Efficient water operation and management of an irrigation system plays an important element in the sustainability of irrigated agriculture. An agricultural water is delivered in many open canals of irrigation delivery system by reservoirs. The poor water distribution and management in an irrigation system is a major factor leading to low water efficiency. It is necessary to compare the estimated irrigation demands with the actual water supplies for decision making to maintain the water supply according to demand strategy. Smarter water management, new technologies and improvement of water management system, is essential to solve the problem of water efficiency and availability. In this paper, the irrigation efficiencies according to water delivery performance indicator were measured with automatic water gauge at irrigation canals, and calculated from spatial and temporal distribution of water supply for the lack of planning in water delivery. The analysis of results are obtain an insight into possible improvement methods to develop canal water management policies that enable irrigation planners to optimally manage scarce available water resources.

• Horticultural Science & Technology
• /
• v.34 no.3
• /
• pp.396-404
• /
• 2016

In this study, four cultivars of strawberry commonly grown in South Korea, 'Daewang', 'Seolhyang', 'Maehyang', and 'Ssanta', were evaluated for several qualities, including the presence of phytochemicals, sugar content, organic acids, and fruit hardness. The plants were cultivated on a high-bench bed system in a plastic greenhouse and drip irrigated. Fruit samples were collected three times in February 2013 to analyze the fruit characteristics. We found that the fruit hardness of the 'Daewang', 'Maehyang', and 'Ssanta' cultivars was greater than that of 'Seolhyang', however 'Seolhyang' showed the highest moisture content of all the cultivars, indicating that fruit hardness was negatively associated with moisture content. Furthermore, 'Seolhyang' was found to have the highest levels of phenolic compounds and anthocyanins compared to the other cultivars. 'Maehyang' had the highest amount of total sugars. 'Seolhyang' and 'Maehyang' accumulated higher amounts of total organic acids. As a result, 'Daewang' and 'Maehyang' were expected to be preferred by consumers because they had the highest ratio of sugar to total acid in their fruit.

• The Korean Journal of Food & Health Convergence
• /
• v.4 no.2
• /
• pp.7-11
• /
• 2018

Salinity is one of the major and increasing problems in irrigated agriculture in Pakistan. Salinity stress negatively affects the growth and yield of plants guar (Cyanoposisa tetragonoloba). This experiment was conducted to evaluate the effects of ($4dSm^{-1}+13.5(mmol\;L^{-1})^{1/2}$, $5dSm^{-1}+25(mmol \;L^{-1})^{1/2}$, $5dSm^{-1}+30(mmol\;L^{-1})^{1/2}$, $10dSm^{-1}+25(mmol\;L^{-1})^{1/2}$ and $10dSm^{-1}+30(mmol \;L^{-1})^{1/2}$) on biomass yield of guar against salinity tolerance. Maximum biomass yield ($54.50gpot^{-1}$) was produced by $4dSm^{-1}+13.5(mmol\;L^{-1})^{1/2}$ treatment. Biomass produce was reduced with the increase of the salts toxicity. Minimum biomass yield ($30.17gpot^{-1}$) was attained under $10dSm^{-1}+30(mmol \;L^{-1})^{1/2}$. $5dSm^{-1}+25(mmol\;L^{-1})^{1/2}$ treatment exhibited improved outcome i.e. the least diminution % over control (18.66). Salinity cum sodicity showed staid effect on the growth reduction from 18.66% to 44.64%. This reduction fissure was impacted by the toxic effect of salinity and sodicity on Guar growth. Salinity- sodicity behaved toxic impact on the growth reduction from 18.66% to 44.64%. Based on the findings, guar (Cyanoposisa tetragonoloba) grows better at $4dSm^{-1}+13.5(mmol \;L^{-1})^{1/2}$ treatment.

• Korean Journal of Environmental Agriculture
• /
• v.27 no.1
• /
• pp.10-17
• /
• 2008

The objective of this study was to estimate the pollutant loads from paddy fields by cultivation practices using a non-point-sources models. One of them is CREAMS-PADDY model that was developed considering the water balance and mass balance of paddy fields. The CREAMS-PADDY model was applied to provide basic data to reduce runoff loadings under various scenarios such as various water management control and various fertilizer condition. The model was verified against T-N, T-P and runoff flow data collected during cropping periods at 2000. The model results agreed well with the measured data in verification. The results showed that the model could be used for estimating the runoff loadings from irrigated paddy fields by cultivation practices was possible. Comparison of simulated the standard height and the sluice management of T-N and T-P runoff loadings from paddy fields were +32.4%, +10.3% in 10 mm below the standard height, -29.2%, -35.9% in 20 mm above the standard height, 52.6%, 59.0% in 40 mm above the standard height, respectively. Comparison of simulated the standard fertilizer and the fertilizer control of T-N and T-P runoff loadings from paddy fields were -1.3%, -21.7%in reduction of conventional fertilizer 30%, -1.0%, -12.5% in reduction of standard fertilizer 30%, respectively. Therefore, reducing nonpoint-sources nutrient loading by reducing fertilization may not work well in the range of normal paddy rice farming practices, and instead it could be achieved by reducing surface drainage outflow.

• Korean Journal of Environmental Agriculture
• /
• v.37 no.4
• /
• pp.317-323
• /
• 2018

BACKGROUND: This study was conducted to evaluate the water-dispersible clay content of paddy soils over the country in the summer rainy season as affected by cultivated years using heavy agro-machinery and soil properties such as texture and exchangeable sodium percentage. METHODS AND RESULTS: Water-dispersible clay content of 16 soil series of Korean paddy soils over the country were investigated in summer rainy season from July to August, 2006 by Middleton's method. Water-dispersible clay content ranged from non-detected to 4.8%, showing maximum value from the fine textured soils and high clay dispersibility in average from the coarse textured soils. Longer cultivated years using agro-machinery more than 40 hp result in higer water-dispersible clay content for 60% of studied paddy soils with less than 5% of exchangeable sodium percentage (ESP). Exceptionally, soils with relatively big difference of ESP at about 10 percent showed higher water-dispersible clay content with higher ESP. CONCLUSION: Long years of cultivation using agro-machinery with more than 40 hp enhanced water-dispersiblility of clay in approximately 60% of the studied paddy fields except for salt-affected soils.

• Journal of Life Science
• /
• v.30 no.5
• /
• pp.411-419
• /
• 2020

The development of GM crops has gained significant economic importance, and the number of countries cultivating commercial GM crops has continuously increased since the 1960s. Globally, the area given to cultivating GM soybean, maize, cotton, and canola alone had reached 114 million hectares by 2007. Although the economic importance of cultivating and commercializing GM crops has increased, there is still a need to assess their agricultural traits in comparison to non-GM produce. This study evaluated the agricultural traits of GM rice containing the drought-tolerant gene CaMsrB2 and standard rice to investigate any unintended effects of genetic engineering. The GM and non-GM rice were compared in terms of various agricultural traits in a drought greenhouse and an irrigated paddy field. There was no statistical difference in the field-grown crops, but there was a statistically significant difference in both tiller number and yield in the greenhouse. These results therefore suggest that GM rice lines containing the CaMsrB2 gene are superior in performance to non-GM rice in drought stress conditions and could be grown in drought-prone areas where drought intolerant rice may not be able to grow.

• Korean Journal of Environmental Agriculture
• /
• v.5 no.1
• /
• pp.11-23
• /
• 1986

Soils and rice plants in wastewater irrigated area of the Mangyeong River receiving waster from the Jeonju Industrial Complex and municipal sewage were sampled at two depths to assess the nature and content of Cd, Cu, Pb and Zn, particularly with respect to distance from wastewater source. For metal levels of soils in these area, no difference in the heavy metal contents between the surface and the subsurface soils was found. Total contents of Cu, Pb and Zn in soils were negatively correlated with distance from the source. A positive correlation was found between contents of total and 0.1N-HCl extractable or $1N-CH_3COONH_4$ extractable heavy metals in surface soils of these area. Total contents of heavy metals in soils were positively correlated with clay, soil organic matter and cation exchange capacity. Heavy metal contents of brown rice sampled at the Jeon-ju Industrial Complex area ranged from 0.15 to 0.91 ppm for Cd, from 1.13 to 5.68 ppm for Cu, from 0.22 to 7.16 ppm for Pb and from 11.74 to 38.66 ppm for Zn. Negative correlation was found between the contents of Cd, Cu, Pb, and Zn in the brown rice and the distance from the source. The contents of Cd, Cu and Zn in rice straw were positively correlated with those in the brown rice.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.405-412
• /
• 2015

Forty schools having natural turf playgrounds were investigated by on-spot investigation and oral interviews with relevant school officials to find out basic information on turfgrass management practices of school playgrounds in Gyeonggi province. Average area of playground was $3,890m^2$ per school and $12m^2$ per student. Ninety five percent of turf playgrounds were managed by school staff and ninety percent of schools spent less than 5 million won per year for turf management. The difficulties in turfgrass management were considered as a major challenge for the schools, followed by turfgrass management cost. Among the management practices, school officials pointed out weed management as the most difficult work, followed by irrigation. The average number of fertilization and mowing was 2 and 6 times per year, respectively. About the half of playgrounds were irrigated only when there was wilting symptom. Zoysiagrass was the most popular choice for the school playgrounds and only three school playgrounds were established with pop-up irrigation system. Fourteen school playgrounds had good turf quality but the rest of school playgrounds had inadequate turf quality requiring minor or full renovation.

• FLOWER RESEARCH JOURNAL
• /
• v.16 no.3
• /
• pp.205-210
• /
• 2008

Sedum kamtschaticum has been used as one of the native valuable plants for ornamental purpose. This experiment was conducted to find out the optimum media for pot cultured Sedum kamtschaticum using peatmoss and coir-based mixtures. Four mixtures such as peatmoss:perlite(5:5, v/v), peatmoss:perlite(7:3, v/v), coir:perlite(5:5, v/v), and coir:perlite(7:3, v/v) were used. Plants were irrigated with a Sonneveld solution in an ebb & flow system. The content of T-N, K, and Ca in the peatmoss-based media was higher than those of the coir-based media. The concentration of T-N, K, and Ca in the shoots of Sedum kamtschaticum increased when plants were cultured with peatmoss-based media. In the peatmoss-based media, plant growth, such as number of branches, leaf length and shoot fresh and dry weights, were significantly increased than those of plant grown in the coir-based media. As the results, the optimum media for pot cultured Sedum kamtschaticum in an ebb & flow system was considered to be the peatmoss-based mixtures.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1263-1263
• /
• 2001

The amounts of organic matter present in soil and the rate of soil organic matter (SOM) turnover are influenced by agricultural management practice, such as rotation, tillage, forage plow down direct seeding and manure application. The amount of nutrients released from SOM is highly dependent upon the state of the organic matter. If it contains a large proportion of light fractions (low-density) more nutrients will be available to the glowing crops. However, if it contains mostly heavy fractions (high-density) that are difficult to breakdown, then lesser amounts of nutrients will be available. The state of the SOM and subsequent release of nutrients into the soil can be predicted by NIRS as long as a robust regression equation is developed. The NIRS method is known for its rapidity, convenience, simplicity, accuracy and ability to analyze many constituents at the same time. Our hypothesis is that the NIRS technique allows researchers to investigate fully and in more detail each field for the status of SOM, available moisture and other soil properties in Alberta soils for precision farming in the near future. One hundred thirty one (131) Alberta soils with various levels (low 2-6%, medium 6-10%, and high >10%) of organic matter content and most of dry land soils, including some irrigated soils from Southern Alberta, under various management practices were collected throughout Northern, Central and Southern Alberta. Two depths (0- 15 cm and 15-30 cm) of soils from Northern Alberta were also collected. These air-dried soil samples were ground through 2 mm sieve and scanned using Foss NIR System 6500 with transport module and natural product cell. With particle size above 150 microns only, the “Ludox” method (Meijboom, Hassink and van Noorwijk, Soil Biol. Biochem.27: 1109-1111, 1995) which uses stable silica, was used to fractionate SOM into light, medium and heavy fractions with densities of <1.13, 1.13-1.37 and >1.37 respectively, The SOM fraction with the particle size below 150 microns was discarded because practically, this fraction with very fine particles can't be further separated by wet sieving based on density. Total organic matter content, mechanical texture, ash after 375$^{\circ}C$, and dry matter (DM) were also determined by “standard” soil analysis methods. The NIRS regression equations were developed using Infra-Soft-International (ISI) software, version 3.11.