• Korean Journal of Environmental Agriculture
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• v.26 no.2
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• pp.107-115
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• 2007

Objective of this study was to assess the efficient rice cultivation practice to mitigate the non-point source pollutants loading to the adjacent watershed. Cultivation practices consisted of machine transplanting, direct seeding on dry paddy, and no tillage in which no fertilizer and pesticide were applied to paddy field. Water in drainage canal was used as irrigation source during the entire rice growing season. Loading of the non-point source pollutants to the adjacent small stream was mitigated by all treatments. Rice yield, total biomass (rice + weeds), and uptake T-N, $P_2O_5$, and $K_2O$ were higher in machine transplanting practice than those in direct seeding and no tillage practices. However, the purification effects of non-point source pollutants were followed in orders of no tillage > direct seeding > machine transplanting due to quantity of irrigation water. The annual purification quantity of T-N, T-P, and K by rice cultivations ranged from 46 to 369 kg $ha^{-1}$, 4.1 to 16.4 kg $ha^{-1}$, and 55 to 238 kg $ha^{-1}$, respectively, during the entire rice growing season. Results revealed that no tillage practice of rice cultivation was the best management option in reducing the loading of the non-point source pollutants from the drainage canal into stream.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.204-207
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• 2007

This study was conducted to suggest proper water management practices after and before broadcasting of rice seed on flooded paddy surface at reclaimed saline soil with two different saline levels in Gyehwado Substation of Honam Agricultural Research Institute (HARI) NICS, RDA for two years from 2004 to 2005. The stable seedling stand in low saline soil of 0.1% salinity was obtained by one time of water exchange after soil rotary Whereas in medium saline soilof 0.3% salinity, three times of water exchange was required for the stable seedling stand. Milled rice yield was not affected by frequency of water exchange in low saline soil, while it decreased sharply in one and two times of water exchange compared with three times of water exchange in medium saline soil. Irrigation water immediately after direct seeding increased the number of seeding stand in low saline soil. With the increase in the interval of water exchange after direct seeding, the milled rice yield decreased. Although the continuous water flowing showed the most number of seedling stand and was increased milled rice yield compared with the others interval of water exchange in medium saline soil, the number of seedling stand and milled rice wasn't significantly different up to exchange of two days interval compared with the continuous water flowing.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.194-204
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• 2020

Cultivar parameters, which are key inputs to a crop growth model, have been estimated using observation data in good quality. Observation data with high quality often require considerable labor and cost, which makes it challenging to gather a large quantity of data for calibration of cultivar parameters. Alternatively, data in sufficient quantity can be collected from the reports on the evaluation of cultivars by region although these data are of questionable quality. The objective of our study was to assess the quality of crop and management data available from the reports on the regional adaptation trials for rice cultivars. We also aimed to propose the measures for improvement of the data quality, which would aid reliable estimation of cultivar parameters. DatasetRanker, which is the tool designed for quantitative assessment of the data for parameter calibration, was used to evaluate the quality of the data available from the regional adaptation trials. It was found that these data for rice cultivars were classified into the Silver class, which could be used for validation or calibration of key cultivar parameters. However, those regional adaptation trial data would fall short of the quality for model improvement. Additional information on management, e.g., harvest and irrigation management, can increase the quantitative quality by 10% with the minimum effort and cost. The quality of the data can also be improved through measurements of initial conditions for crop growth simulations such as soil moisture and nutrients. In addition, crop model improvement can be facilitated using crop growth data in time series, which merits further studies on development of approaches for non-destructive methods to monitor the crop growth.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.98-104
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• 2001

Cultivation area of the plastic film-house has been continuously increased with the increase of consumers' income. Intensive land use without fallowing or crop rotation caused severe problem such as salt accumulation in soils and in turn retarded growth and low productivity. This study was carried out to solve them derived from longterm intensive farming practices. Seven farmers who are practicing plastic film-house cultivation were recommended for case study by municipal government and selected for their excellency of cultivation and soil management. The cultivation periods of these systems were in the range of 5 to 40 years in the regions mainly located in alluvial soil cultivated with cucumber, tomato and red pepper. The soils texture of the excellent farmers' fields were silt loam or sandy loam, ranged from 7 to 15 percents of clay contents. Soil bulk density, depth of plowing layer and soil aggregates contents of the farmers' soils were 0.89, 23.1 cm, 61.6% whereas those in neighboring soils were 1.10, 17.8 cm, 54.2 %, respectively. And pH, OM and $NO_3-N$ of the farmers' soils also were better than those of neighboring soils. There was no difference in population densities of nematode between the good farmers' and neighboring soils, but actinomyces and Fusarium densities of recommended farmers' soils were better than neighboring soils. The major farming practices by the good farmers were characterized by deep plowing with flooding, amendment of crude organic matter, and reduction of chemical fertilizer application before transplanting, and also drip irrigation and liquid manure application after planting. They also conducted solar sterilization with or without flooding, removal of plastic films during rainy days and culturing rice or corn as rotation crops to avoid the problems mentioned above.

• Journal of Korea Water Resources Association
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• v.52 no.9
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• pp.637-645
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• 2019

Among various ecosystem services provided by the basin, this study deals with water yield (WY) estimation in the Bagmati basin of Nepal. Maps of where water used for different facilities like water supply, irrigation, hydropower etc. are generated helps planning and management of facilities. These maps also help to avoid unintended impacts on provision and production of services. Several studies have focused on the provision of ecosystem services (ES) on the basin. Most of the studies have are primarily focused on carbon storage and drinking water supply. Meanwhile, none of the studies has specifically highlighted water yield distribution on sub-basin scale and as per land use types in the Bagmati basin of Nepal. Thus, this study was originated with an aim to compute the total WY of the basin along with computation on a sub-basin scale and to study the WY capacity of different landuse types of the basin. For the study, InVEST water yield model, a popular model for ecosystem service assessment based on Budyko hydrological method is used along with ArcGIS. The result shows water yield per hectare is highest on sub-basin 5 ($15216.32m^3/ha$) and lowest on sub-basin 6 ($10847.15m^3/ha$). Likewise, built-up landuse has highest WY capacity followed by grassland and agricultural area. The sub-basin wise and LULC specific WY estimations are expected to provide scenarios for development of interrelated services on local scales. Also, these estimations are expected to promote sustainable land use policies and interrelated water management services.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.11a
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• pp.3-31
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• 1997

Water has always played a significant role in the lives of people. In urbanised Rome, with its million people. sophisticated supply systems developed and then fled with the empire. only to be rediscovered later But it was the industrial Revolution commencing in the eighteenth century that ushered in major paradigm shifts In use and altitudes towards water. Rapid and concentrated urbanisation brought problems of expanded demands for drinking supplies, waste management and disease. The strategy of using water from local streams, springs and village wells collapsed under the onslaughts of rising urban demands and pollution due to poor waste disposal practices. Expanding travel (railways. and steamships) aided the spread of disease. In England. public health crises peaks, related to water-borne typhoid and the three major cholera outbreaks occurred in the late eighteenth and early nineteenth century respectively. Technological, engineering and institutional responses were successful in solving the public health problem. it is generally accepted that the putting of water into pipe networks both for a clean drinking supply, as well as using it as a transport medium for removal of human and other wastes, played a significant role in towering death rates due to waterborne diseases such as cholera and typhoid towards the end of the nineteenth century. Today, similar principles apply. A recent World Bank report Indicates that there can be upto 76％ reduction in illness when major water and sanitation improvements occur in developing countries. Water management, technology and thinking in Australia were relatively stable in the twentieth century up to the mid to late 1970s. Groundwater sources were investigated and developed for towns and agriculture. Dams were built, and pipe networks extended both for supply and waste water management. The management paradigms in Australia were essentially extensions of European strategies with the minor adaptions due to climate and hydrogeology. During the 1970s and 1980s in Australia, it was realised increasingly that a knowledge of groundwater and hydrogeological processes were critical to pollution prevention, the development of sound waste management and the problems of salinity. Many millions of dollars have been both saved and generated as a consequence. This is especially in relation to domestic waste management and the disposal of aluminium refinery waste in New South Wales. Major institutional changes in public sector water management are occurring in Australia. Upheveals and change have now reached ail states in Australia with various approaches being followed. Market thinking, corporatisation, privatisation, internationalisation, downsizing and environmental pressures are all playing their role in this paradigm shift. One casualty of this turmoil is the progressive erosion of the public sector skillbase and this may become a serious issue should a public health crisis occur such as a water borne disease. Such crises have arisen over recent times. A complete rethink of the urban water cycle is going on right now in Australia both at the State and Federal level. We are on the threshold of significant change in how we use and manage water, both as a supply and a waste transporter in Urban environments especially. Substantial replacement of the pipe system will be needed in 25 to 30 years time and this will cost billions of dollars. The competition for water between imgation needs and environmental requirements in Australia and overseas will continue to be an issue in rural areas. This will be especially heightened by the rising demand for irrigation produced food as the world's population grows. Rapid urbanisation and industrialisation in the emerging S.E Asian countries are currently producing considerable demands for water management skills and Infrastructure development. This trend e expected to grow. There are also severe water shortages in the Middle East to such an extent that wars may be fought over water issues. Environmental public health crises and shortages will help drive the trends.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.458-462
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• 2013

A drainage ditch is normally a component of drainage networks in farming systems to remove surplus water, but at the same time, it may act as a major conduit of agricultural nonpoint source pollutions such as sediment, nitrogen, phosphorus, and so on. The hybrid turbidity reduction system using biodegradable check dam and synthetic polymer was developed in this study to manage pollutant discharge from agricultural farmlands during rainfall events and/or irrigation periods. The performance of this hybrid system was assessed using a laboratory open channel sized in 10m-length and 0.2m-width. Various check dams using agricultural byproducts (e.g., rice straw, rice husks, coconut fiber and a mixture of rice husks and coconut fiber) were tested and additional physical factors (e.g., channel slope, flowrate, PAM dosage, turbidity level, etc.) affecting on turbidity reduction were applied to assess their performance. A series of lab experiments clearly showed that the hybrid turbidity reduction system could play a significant role as a supplementary of Best Management Practice (BMP). Moreover, the findings of this study could facilitate to develop an advanced BMP for minimizing nonpoint source pollution from agricultural farmlands and ultimately to achieve the sustainable agriculture.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.413-419
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• 2009

The appropriate dripper position in perlite bag was investigated for tomato production. Drippers were laid at 5(F5), 15cm (F15) away from the stem base or 5cm at first and then moved to 15cm later (M5-15). Roots were developed more near the stem base in F5, while less in F15. Roots were distributed evenly in M5-15. In vertical distribution of water in perlite bag, water content was higher as it went deeper with the variation by dripper positions. Yield was high in F15 and low in F5. In conclusion the position of dripper is the best at 15cm from the stem base in perlite bag culture in view of root distribution and yield.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.117-122
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• 2007

This study was investigated the potential of ducks and fish trap for the control of golden apple snail, Pomacea canaliculata, in paddy field and water canals. The smaller size of duck (700g) preyed snails than the bigger one (1,300g). The consumption of two ducks was bigger under plastic house. They preyed over 90% on the second days of release. The release time of ducks was more effective at seven days after inoculation of snails than simultaneous. Duck could suppress the density of snails at any time from month after inoculation. Four ducks per $30m^2$ could control snails in an irrigation canals. The number of attracted golden apple snail per week was 216 in big fish trap $({\Phi}15cm)$ with menthol paste which for a carp.