• Magazine of the Korean Society of Agricultural Engineers
• /
• v.20 no.1
• /
• pp.4614-4625
• /
• 1978

The construction of the equipment of water utilization has been developed since the ancient Korea period, 1906 in order to develope and modernize the agriculture. As the results, 83% of total paddy field area, 1,268,949.8 ha has developed into the irrigated paddy field, and the rest of area, 17% has remained nonirrigated paddy field (due to the data of the statistics of 1975). The ratio of the irrigated paddy field area among the total weir was marked 13.14% (area, 137,926.3 ha) and the third grade of total irrigated paddy field in accordance with the facilities of water utilization. In case of Gangwon-Do, the 44.18 percentage of the total irrigated paddy field, 51,057.2ha has been and pointed out first grade. As the results, we found out the following articles : 1. The total weir, 1,641 that sumed concrete weir 647 and conventional weir 967 has been constructed and has irrigated the 44.l8% of total irrigated paddy field of Gangwon-Do. 2. These weirs have been public possession of those villages to be 96.1 percentage of total weir and was controled by them. 3. Those weirs that were constructed across tributary (first, secondary and third tributary) at vallies (elevation 100∼1,000m) have marked that 45 percentage of total number of catchment area has 100∼1,000 ha, and 70 percentage of total number of basin area has been below 10 ha and has constructed about 5 of step-shape. 4. The construction of most weirs has became generally about 50m length, about 1m height. 5. The 80 percentage of newly constructed concrete weir has aged below 10 years. It seemed that 79 percentage of conventional weir has aged over 20 years and 41% of contructed weir has needed to be improved quickly. 6. If privious weirs, 296 will constructed newly, they can irrigate 3,600.8 ha of paddy field and 45.8% of total irrigated paddy field will have been and will contribute to the production of much rice.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.2
• /
• pp.81-88
• /
• 2003

Soybeans [Glycine max (L.) Merr.] are frequently exposed to unfavorable environments during growing seasons and water is the most important factor limiting for the production system. The purpose of this study was to determine the leaf water potential changes by irrigation, and to evaluate the relationships of leaf water potential, growth and yield in soybeans. Three soybean cultivars, Hwangkeumkong, Shinpaldalkong 2, and Pungsannamulkong, were planted in growth chamber and field with irrigated treatments. Leaf water potential of three soybean cultivars was positively correlated with leaf water content during vegetative and reproductive growth stages in growth chamber and field experiments. Leaf water potentials measured for three soybean cultivars under growth chamber were higher than those of under field conditions. Higher leaf water potential with irrigated plots under field was observed compared to conventional plots during reproductive growth stages. Leaf water potentials of three soybean cultivars were continually decreased during reproductive growth stages under field and there was no significant difference among them. Number of leaves, leaf water content, pod dry weight, number of seeds and seed dry weight with irrigated plots were higher than those of conventional plots. The results of this study suggested that leaf water potential could be used as an important growth indicator during the growing season of soybean plants.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.230-230
• /
• 2017

About 200 rice varieties for irrigated and rainfed lowland ecosystems were released in the Philippines, which were bred for improving yield under favorable conditions. Root plasticity plays key roles in maintaining crop productivity under abiotic stressed conditions. We hypothesized that some of these varieties possess root plasticity traits in response to water stressed conditions. This study aimed to evaluate the root system development and dry matter production of 14 randomly selected rice varieties (6 irrigated lowland and 9 rainfed varieties) under progressive drought (PDR) and soil moisture fluctuations (SMF) stress conditions. Two experiments were done in rootbox and line source sprinkler systems (LSS). Each of the varieties was subjected to well-watered (WW), PDR and SMF conditions during vegetative stage in rootbox system while the same genotypes were subjected to different intensities of drought stress under LSS. Under rootbox system, PDR and SMF significantly reduced shoot dry matter production in all varieties relative to their WW controls. Among varieties, NSIC Rc238 (irrigated lowland) showed the least reduction in shoot dry weight (SDW) in both PDR (by 11.8%) and SMF (by 26.9%) conditions. Less reductions in SDW of NSICRc238 were partially attributed to the promotion of L-type lateral roots, thus increasing total lateral root length by 24.2% and 30.7% under PDR and SMF, respectively. In LSS, SDW of NSIC Rc238 under mild drought stress (16-21% soil moisture content (SMC) had 31.8% reduction relative to its WW control (${\geq}22%SMC$) and had lower sensitivity drought index. Compared with the IR64 susceptible check and NSIC Rc9 tolerant check, NSIC Rc238 had higher SDW by 90.8% and 38.6%, respectively. Furthermore, no rainfed lowland varieties included in the experiment performed well under different water stress treatments. The results implied that some other irrigated lowland rice varieties may also possess drought dehydration avoidance root plasticity traits under water-stressed growing environments.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.44 no.3
• /
• pp.146-156
• /
• 2002

The objective of this study was to develop a modified CREAMS model for paddy field conditions. The model simulates daily balance of water and nutrient from irrigated paddies using meteorological, irrigation, and agricultural management data. The model simulates daily evapotranspiration of paddy using Penman equation and determines daily flooding depth changes. Total nitrogen and phosphorus concentrations within flooding water, surface runoff, and leaching water from a paddy field also can be simulated. Parameters of the model were calibrated using observed data of the Agricultural Experiment Station of the Seoul National University in Suwon Korea. The model was applied for the irrigation period of paddy field in Gicheon area when 1,234 mm annual rainfall was occurred. The simulated losses of the total nitrogen and total phosphorous were 11.27 kg/ha and 0.98 kg/ha, respectively. There was a good agreement between observed and simulated data. It was found that CREAMS-PADDY model was capable of predicting runoff and nutrient losses from irrigated paddy fields.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2001.10a
• /
• pp.89-92
• /
• 2001

This study was to analyse the correlations between pumping rate to irrigated area and rainfall amount in the Geum river basins. A total of 84 pumping stations and field data from the paddy of 28,772 ha were introduced to the analysis. The results showed that the pumping volume was highly correlated to the rainfall during the irrigation period and irrigated area. But, it was difficult to determine the exact correlation factors, because of the lack of data like the efficiency of water in the paddy field.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.56 no.6
• /
• pp.19-29
• /
• 2014

The objectives of this study were to monitor and analyse water quality and soil property in paddy fields where untreated wastewater is irrigated. Three paddy fields where streamflow mixed with untreated wastewater has been irrigated (untreated wastewater district, UWD) were selected for monitoring, and five paddy fields in Yongin area (Yongin district, YID) where water from Idong agricultural reservoir (well-managed) has been irrigated were selected for comparative evaluation. Electronic conductivity (EC), suspended solids (SS), total nitrogen (T-N), total phosphorous (T-P), $NO_3-N$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, total coliform (TC), fecal coliform (FC), and E. coli of the irrigation water in the UWD were significantly higher than those in the YID. Relatively high concentrations of EC, T-N, T-P, TC, FC, E. coli, copper (Cu), lead (Pb), zinc (Zn), and aluminium (Al) were shown in the irrigation water of the UWD especially during May to June. In general, the paddy soil in the UWD contained more Pb, Zn, and Cu than in the YID although the soil heavy metal contents in the UWD still meet the Korean soil contamination warning standards. No temporal trends in the heavy metal concentrations were found in paddy soils of the UWD. This study showed that the use of untreated wastewater to paddy fields has the possibility of negative impacts on water quality and soil, although long-term monitoring is needed to fully evaluate its effects.

• Environmental Engineering Research
• /
• v.13 no.3
• /
• pp.107-111
• /
• 2008

Water quality contamination issues are of critical concern to human health, whilst pesticide release generated from irrigated land should be considered for protecting natural habitats and human health. This paper suggests new method for evaluation and analysis using the GIS technique based on integrated spatial modeling framework. The pesticide use on irrigated land is a subset of the larger spectrum of industrial chemicals used in modern society. The behavior of a pesticide is affected by the natural affinity of the chemical for one of four environmental compartments; solid matter, liquid, gaseous form, and biota. However, the major movements are a physical transport over the ground surface by rainfall-runoff and irrigation-runoff. The irrigated water carries out with the transporting sediments and makes contaminated water by pesticide. This paper focuses on risk impact identification and assessment using GIS technique. Also, generated data on pesticide residues on farmland and surface water through GIS simulation will be reflected to environmental research programs. Finally, this study indicates that GIS application is a beneficial tool for spatial pesticide impact analysis as well as environmental risk assessment.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2000.10a
• /
• pp.629-636
• /
• 2000

In this study, we investigated the characteristics of labor of water management and maintenance, water requirement, water quality(T-N, T-P, COD) in the paddy plot irrigated by pipeline with two types of hydrants: automatic and manual. The automatic hydrant have been introduced to the paddy field to save water and reduce the labor for water management. The automatic hydrant is automatically opened and closed according to the water depth of a paddy plot. The automatic hydrant generally developed more troubles than the manual hydrant. The water requirements are 2.7mm/d for the automatic hydrant plot and 17.6mm/d for the manual hydrant plot. The concentrations of pollutants in the two plots are higher in the ponded water than in the irrigation water and are highest after fertilizer application.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2000.10a
• /
• pp.138-143
• /
• 2000

CREAMS-PADDY model for simulating daily water and nutrient balance at irrigated paddies was developed, applied to, and validated with field data. The model simulates daily flooding depth and total nitrogen and phosphorus concentrations from meterorological, irrigation, and farming data. Simulated results from the model were in good agreement with field data. Among different scenarios to reduce nutrient losses from paddies, the water management was found to be very effective, and recommended for field applications.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.2
• /
• pp.125-131
• /
• 2011

BACKGROUND: Reuse of waste nutrient solution for the cultivation of crops could lead to considerable conservation of water resources, plant nutrients, and water quality. Therefore, this study was conducted to evaluate the potential for reducing the use of chemical fertilizer in Chinese cabbage cultivation via the reuse of waste nutrient solution as an alternative irrigation resource. METHODS AND RESULTS: The nutrients supplied in the waste nutrient solution consisted of 1474.5, 1285.1, 991.6, and 872.6 mg/L for $K+$, ${NO_3}^-$, $Ca^{2+}$ and ${SO_4}^{2-}$, respectively. At 56 days after transplanting (DAT), the leaf length of Chinese cabbage plants irrigated with the waste nutrient solution treatment was significantly higher than that of plants irrigated using a conventional groundwater treatment. Additionally, the leaf width, fresh weight and dry weight of the plants irrigated with the waste nutrient solution were similar or greater than that of plants irrigated with a conventional treatment. Furthermore, the growth of plants treated with the waste nutrient solution +25% fertilizer was the highest among all tested treatments. CONCLUSION(s): These results indicate that the waste nutrient solution can be used as an alternate water resource for crop cultivation. In addition, it can contribute to reduce the fertilizer and to obtain the higher crop yield of Chinese cabbage.