• Korean Journal of Organic Agriculture
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• v.14 no.1
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• pp.69-83
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• 2006

This experiment was conducted to investigate effects of application of diluted and undiluted cattle slurry with water on seasonal and annual dry matter yields and feed values of tall fescue in the uncultivated rice paddy and it was compared with chemical fertilizer. Annual dry matter yields for diluted (average 6.43 ton DM/ha) and undiluted (average 6.56 ton DM/ha) cattle slurry were significantly higher (p<0.05) than those of no fertilizer (3.82 ton DM/ha). This trend was much more conspicuous in treatments applied in spring. In chemical fertilizer treatments, fertilizers with P and K (6.12 ton DM/ha), and P, K and N (10.13 ton DM/ha) had significantly (p<0.05) higher dry matter yields compared with no fertilizer. However, annual dry matter yields for treatments of P and K mixture tended to be lower than those of cattle slurry applications. The efficiency of DM production for inorganic nitrogen in chemical fertilizers annually averaged 26.7kg DM/kg N. In terms of cutting frequencies, it was highest in 2nd growth followed by 1st and 3rd growth. On the other hand, efficiencies of annual DM production of nitrogen for diluted and undiluted cattle slurry were 18.3 and 17.4 kg DM/kg N, respectively, especially, highest in 2nd growth. While, efficiencies of DM production for cattle slurry versus for inorganic nitrogen were 68.5 (undiluted) and 65.2% (diluted), respectively. For annual crude protein contents of tall fescue, no fertilization (11.5%) was significantly higher than chemical fertilizer, but that was lower than cattle slurry ($12.4{\sim}12.6%$) diluted with water. on the contrary, no fertilizers had significantly lower NDF (64.1%) and ADF (37.2%) contents than those of any other treatments, but their RFV (87.0) was significantly higher (p<0.05) than other treatments. The application of cattle slurry and their dilution significantly increased yields of crude protein and total digestible nutrients compared with no and/or P and K fertilizers (p<0.05). This trend was more conspicuous in cattle slurry applied in the early spring.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.230-240
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• 2017

BACKGROUND: To evaluate residues of environmentally concerned pesticides in water system, this monitoring was conducted over three rivers. The residual characteristics and discharging condition of these residues on water system was investigated. METHODS AND RESULTS: Total twenty nine sampling sites were selected through main streams and branch streams of Keum, Mangyung and Dongjin rivers, and the water samples from them were regularly collected one month interval, especially biweekly from May to August in 2002. Of the pesticides monitored, six fungicides which include hexaconazole, isoprothiolane and iprobenfos were detected with frequencies of 0.3-50.9% and in their residue level of $0.1-4.7{\mu}g/L$. Sixteen insecticides which include nine organophosphoruses, three carbamates, endosulfan, cypermethrin, buprofezin and fipronil were detected with frequencies of 0.3-32.5% and in their residue level of $0.01-2.8{\mu}g/L$. Nine herbicides which include alachlor molinate, anilofos, butachlor, dimepiperate, metolachlor, oxadiazon, pretilachlor and thiobencarb were detected with frequencies of 0.8-22.9% and in their residue level of $0.01-9.07{\mu}g/L$. CONCLUSION: Detection frequencies and residue levels of insecticides and herbicides were the highest in waters sampled in May and June. Almost pesticides detected were for the paddy rice and their residue levels were very low to compare with standard values.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.271-280
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• 1994

The aim of this experiment was to investigate the effects of fertilizing mineral nitrogen on dry matter yield of Reed canarygrass and also to estimate proper levels of fertilizing nitrogen when uncultivated rice paddy rapidly increased these days, was used for the production if Reed canarygrass. \ulcornerhe results are as follows. 1. Relative dry matter according to cutting frequency was appeared the highest at the 2nd cut for 3 and 4 cutting frequencies, and the 3rd cut for 5 cutting frequency. Those were 43.1, 34.0 and 34.1 % respectively. 2. When using only phosphrous and potassium, the average dry matter per year and ha was between 9.0 and 12.0 tons(3, 4 and 5 cutting frequency) and the highest dry matter was shown at 5 cutting frequency. 3. In accordance to the increase in the fertilization of nitorgen, the yield of dry matter was increased and, when 30 kg/ha/cut of mineral nitrogen was added, the biggest increase rate per added nitrogen for dry matter yield per year compared to that of no fe~tilization of nitrogen was recorded and it was 2.7, 3.3, and 3.4 tons/ ha for 3, 4 and 5 cutting frequencies respectively. 4. The efficiencies of mineral nitrogen on dry matter yield(DM kg/N kg) were the highest when 30kg nitrogen was applied particularly in 3, 4 and 5 cutting frequencies(29.7, 27.2, 22.8 DM kg/N kg). It recorded the highest of all the treatments. The efficiency was actually decreased in higher application of mineral nitrogen. The total nitrogen yield efficiency was the highest in 30kg(0.45kg and 0.48kg at 4 and 5 cutting frequency) and 60kg fertilization/ha/cut (0.46kg at 3 cuting frequency) and the decreased efficiencies appeared at fertilization of higher nitrogen. 5. Economical borden of mineral nitrogen fertilization were between 199.2 and 243.3kglha at 3 cutting frequency, between 253.4 and 295.9kg at 4 cutting frequency and between 302.2 and 361.3kg at 5 cutting frequency. 6. Under the condition of this experiment, the cutting frequency leading the potential production at maximum was 3 cutting frequency. At 3 cutting frequency, the efficiency of nitrogen utilization was higher and 15 or 16 tons of dry matter was obtained which is a level of economical border at fertilization between 200 and 240kglha. It wrs possible to obtain the maximal dry matter yield(l7 tonslha) at fertilization of lower level than 400kgl ha.

• Magazine of the Korean Society of Agricultural Engineers
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• v.22 no.4
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• pp.82-95
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• 1980

This paper complies the results of the studies so far made on the subsoil improvement of subsurface drainage systems for wet paddy fields (those were located in the Gum-Ho area in Kyung Buk province) which had poor permeability and a high water table. In general, a drainage problem is an excess of water on the ground surface which can effect the productivity and bearing capacity of the soil. With drain pipe systems, (According to their depths and spacing) it may be possible to correct that problem. The experimentation consisted of three test plots, two of which included drain pipe systems with varing depths and width spacing of the pipes. The third plot (C) was an ordinary plot being exempt of a drain pipe system. In detail, the depth of plot A was 80 cm, and the width spacings began at 2. Om and increased by 2. Om up to 10. 0m. The depth of plot B was 60cm and the width spacing was the same as plot A. These tests were performed to research specific details; such as crop yeild, bearing capacity of the soil, the amount of underdrainage, surface cracks, root distribution, the water table level, the consumptive water depth and the soil moisture content. The test period lasted three years, from 1977 thru 1979. The results obtained were as follows: 1. During the test period, the weather conditions for the area tested were in accordance with the annual average for that area. Furthermore the precipitation factor during the spring cultivation season, the intermediate drainage period and the harvest drainage period was of optimum conditions for controling surface cracks, because of less precipitation than evaporation. 2. The difference in the level of the ground water table in plots A and B was hardly noticable, but the difference in the test plots and the ord. plot was greatly noticable. The test plots (A, B) were 30 to 40cm lower than the ordinary plot. On the whole, the ground water table of the ord. plot always stayed at a level of 15-20cm beneath the surface of the soil, the ground water table of the test plot A showed The difference in the depth of the pipe lower than the test plot B, while the test plots showed a remarkable descending effect. 3. The soil temperature in plot A was slightly core than in plot B with a difference of 0. 47$^{\circ}$C, but plot A was 1. 6$^{\circ}$C higher than the ord. plot during the flooding period, but after drainage the temperature difference climed to 2. 0$^{\circ}$C. 4. During the 3rd test year, the values of the cracks were recorded with the values of 59cm in plot A, 42cm in plot B and 15cm in the ordinary plot. Plots A and B had increased 2.5 times the value of the first year while the ordinary plot had remained the same. 5. The root weight of the rice was measured at a value of 77.2 gr. for plot A, 73.5 gr. for plot B and 65.3 gr. for the ord. plot. Therefore, the root growths in plots A and B were much more energetic than in the ord. plot. 6. The consumptive water depth measured during the 3rd year resulted in the values of 26. 0mm per day for plot A, and 24.9 mm per day for plot B, respectively. Therefore, both plot A and plot B maintained the optimum consumptive water depths, but the ordinary plot only obtained the value of 12.3 mm per day, which clearly showed less than the optimum consumptive water depth which is 20 to 30 mm/day. 7. The soil moisture content is in direct relationship to the ground water level. During drainage, test plot A decreased in its ground water level much more rapidly than the other two plots. Therefore, plot A had a much less soil moisture content. But this decreased water level could be directly effected by the weather conditions. 8. The relationship between the bearing capacity and the soil moisture content were directly inversely proportional. It can be assumed that the occurence of soil creaks is limited by the soil moisture content. Therefore, the greater the progress of the surface creaks resulted in a greater bearing capacity. So, tast plot A with a greater amount of surface cracks than the other test plots resulted in a greater bearing capacity. But, the bearing capacity at the harvest season could be effected by the drainage during the intermediate drainage period and by the weather conditions. 9. Comparing the production of the test plots to the ord. plot; there was an increased value of 840kg for plot A, 755kg for plot B and 695kg for the ord. plot in the rough rice. Therefore, plot A had an increase of 20% over the ordinary plot. The possibility of producing double crops was investigated. The effects on barley production in the test plots showed a value of 367kg per 10 acres, which substantiated the possibility of double crops because that value showed an increased value over the average yearly yield for those uplands. 10. So as a result, it can be recommended that by including a drain pipe system with the optimum conditions of an (80cm centimeter) depth and a (l0m) spacing will have a definite positive effect on the over all production capacity and quality of wetpaddy fields.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.1
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• pp.50-56
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• 1994

This study was investigated for the purposes of securing forage resource using idled rice paddy recently increased in accordance to a current trend of farm products' liberalization and also of presevation of environment by using cattle sluny as liquid manure, which is seriously increasing these days. In this study, mean annual dry matter yield and its seasonal variation with reed canarygrass, and a optimum rate of cattle sluny application were investigated. The results are as follows: 1. According to the conditions of cutting frequencies(3, 4 and 5 cutting per year), mean annual dry matter yield was recorded from 8.9 tons to 10.9 tons per hectare and was the highest at 3 cutting frequency. 2. The use of cattle sluny with the levels of between 300 and 360 kg N per hectare showed a significantly higher mean annual dry matter yield than that of the control (non-fertilization). 3. The treatments with 3 and 4 cutting frequencies(90 kg Nhdyear, 120 kg Nhdyear) recorded higher dry matter yields than the control of the former level by 1.23 tons and 2.34 tons respectively and in the treatment of 5 cutting frequency, the second level with cattle sluny of 300 kg Nhdyear showed an increased dry matter yield of 2.11 tons compared to the former level(l50 kg Nhdyear). With regards to nitrogen efficiency, one kg of nitrogen is applied to 13.7, 19.4 and 14.1 kg of dry matter yields in the conditions of 3, 4 and 5 cutting frequencies respectively. 4. In view of seasonal variance of annual dry matter yield, the second cut in 3 cutting frequency, the third cut in 4 cutting frequency and the third in 5 cutting frequency showed the highest ratio as 42, 37 and 32% respectively compared to the total. 5. Under the conditions of this study, the 'Input-Output curve' from 5 cutting frequency was the closest to sigmaformed process(i=0.9993) of various cutting frequencies, and the maximum marginal yield in the treatment was obtained at the level of 250 kg Nha with cattle sluny. The economic level of cattle sluny was between 371.0 and 402.2 kg N and the highest dry matter yield was obtained at 489.3 kg Mdyear in the same treatment

• Korean Journal of Environmental Agriculture
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• v.9 no.2
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• pp.83-95
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• 1990

This study was conducted to estimate influences of pesticides such as carbofuran[2,3-dihydro-2,2-dimethylbenzofuran-7-yl methyl carbamate] as an insecticide, and pyrazolate [4-(2,4-dichlorobenzolyl)-1,3-dimethyl-5-pyrazolyl-1,3-dimethyl-5-pyrazolyl-p-toluensulfonate], pyrazolate+pretilachlor [2-chlor-2,6-diethyl-N-(n-propoxyethyl) acetanilied] as herbicides on change in numbers of soil microorganisms and pH in planted and unplanted flooded rice paddy soils. The results of weekly investigated change of pH and populations of total bacteria, gram negative bacteria, anaerobic bacteria and fungi after treatments of pesticides were as follows : The change of pH in rice-planted soil gradually decreased in a matter of weeks after treatment with pesticide and the pH increased again from the sixth week, but no change of pH could be observed in nonplanted soil. The total numer of bacteria in the treated plots were slightly less than in the control plot, and the numbers decreased with increasing application rates of pesticides. But the microbial population increased in a matter of days after treatment with pesticide. Number of the gram negative bacteria until the sixth week after treatment of pesticide were fewer than control. The number in the carbofuran-treated plot decreased after a weeks after treatment, but numbers in plots treated with pyrazolate and pyrazolate+pretilachlor increased. The number of anaerobic bacteria in the treated plots were few by comparison with the untreated control, but the number increased after a weeks after treatment with pesticides. The populations of fungi in the carbofuran-treated plot were similar by comparison with the untreated control. The populations in the plots treated with pyrazolate and pyrazolate+pretilachlor decreased in 4 to 5 weeks with increase of application rate, but afterwards increased.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.394-398
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• 1997

Changes of nutrient material and heavy metals of irrigation water and natural supplies by irrigation water into 1.0ha of paddy field during the rice cultivation was investigated pH of irrigation water ranged 6.458.34 and electrical conductivity showed $110{\mu}S/cm$ in the first irrigation period and commonly showed $90{\mu}S/cm$. The content of T-N, NH4-N and $NO_3-N$were 3.09~12.36, 0.17~1.34 and 2.70~10.72mg/L respectively. The content of T-P was 0.09~0.22mg/L and ortho-P was not detected. The content of $Ca^{++},\;Mg^{++},\;Na^+\;and\;K^+$ showed 0.89~5.12, 1.12~2.76, 1.74~4.52 and 1.34~4.18mg/L regardless of irrigation season respectively. Only Cu and Zn of heavy metals were detected 0.001~0.009 and 0.007~0.091mg/L, but Pb, Cd, Cr and Ni were not detected When supplied $4,250m^3$ of an irrigation water into 1.0㏊ of paddy field, natural supplies of nutrient materials were 29.67㎏ of T-N, 1.80㎏ of $NH_4-N$, 24.57kg of NO3-N and 0.51kg of T-P. Also $Ca^{++},\;Mg^{++},\;Na^+,\;K^+,\;Cl^-\;and\;SO_4\;^{2-}$ were supplied 9.42, 7.09, 13.34, 9.08, 40.27 and 41.38kg respectively. Only Cu and Zn of heavy metals were supplied 0.017kg of Cu and 0.133kg of Zn, Pb, Cd, Cr and Ni were not supplied

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.401-410
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• 2005

A series of studies involving formulation processes, bubbling activity test, diffusibility test and biological efficacy test was undertaken to develop Jumbo herbicide formulations in paddy rice field. Gas evolution speed from the tablets prepared by different organic acids was in the order of oxalic acid, malonic acid, citric acid, and tartaric acid. The total volume of evolved gas from the tablet and diffusibility of the active ingredient in the submerged water were increased with increase of water temperature; the volume from 1 g of tablet at 10, 15, 25 and $30^{\circ}C$ for 5 minutes after immersion into water was 20, 25, 28, 45, 57 mL, respectively. The concentration of halosulfuron-methyl and pyriminobac-methyl in submerged water at 5, 15, 20 and $30^{\circ}C$ at the 2.4 m distance from the applied spot of the tablet was 20, 48, 85, and 97% of the concentration of treated spot, respectively. The evolved gas volume from the tablets was not affected by pH of submerged water. The concentration of halosulfuron-methyl in different sizes of submerged water within 24 hours after treatment of the tablet was maintained 0.16 ppm, which is ideal concentration at standard dosage regardless of the submerged water area. The concentration of pyriminobac-methyl was also uniformly dispersed in the water within 24 hours after applying it into the submerged water. The wind velocity of 5 m $sec^{-1}$ on concentration distribution of halosulfuron-methyl and pyriminobac-methyl in the submerged water 24 hours after treatment was not influenced; an equal concentration in the up the wind and down the wind from the applied spot was maintained. Spot treatments of one tablet formulations(5 g) including 4 times higher dosage at 4 different spots resulted in even concentration distribution of active ingredient in the water 24 hours after applying it into the submerged water.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.158-165
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• 1992

A survey on nation-wide distribution of fresh-water algae occurring in paddy rice fields was conducted in 1991. The algae which were collected from the whole nation were classified into a total of 54 genera including 14 genera in the blue-green algae. 29 genera in the green algae, 1 genus in the stoneworts. 3 genera in the euglenoids and 7 genera in the diatoms. The green algae and diatoms occurring in plain regions were diverse in terms of the number of genera distributed, whereas there was no regional difference in diversity of the blue-green algae and the euglenoids. Among the green algae, the suspended unicellular algae such as the genera, Chlamydomonas, Pandorina and Gonium, were widespread in plain regions, but the multicellular algae such as the genera, Spirogyra, Oedogonium, Ulothrix and Hydordictyon, were major in mountainous and attitudinal regions. The filamentous green algae such as the genera. Cladophora and Rhizoclonium, were dominant in reclaimed saline fields. The blue-green algae Oscillatoria spp. and the diatoms Navicula spp. were abundant in soil flakes.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.124-131
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• 1992

Not only reducing the carry-over effects of quinclorac [3, 7-dichloro-8-quinoline carboxylic acid] used in paddy field to some following vegetable crops but also rationalizing agro-ecology conservation and farm economy, the reducing feasibility of application rates by various cropping patterns and application timing after rice seeding and transplanting. Four cropping patterns namely dry direct seeding(DDS), flooded direct seed(FDS), transplanting of 8 days old early seedlings(EST) and 25 days old machinery seedling(MST) were experimented with 7 application timings as 0, 5, 10, 15, 20, 25, 30 days after seeding/transplanting and 9 levels of application rates as 0, 75, 150, 225, 300, 375, 450, 525, and 600g ai/ha of the chemical, respectively. Within the maximum permitted limit of rice phytotoxicity, the minimum application rate of quinclorac to complete control of Echinochloa crus-galli as influenced by various cropping patterns with application timing could be evaluated as follows : A. Dry direct seeding : The minimized application rate at application timing upto 10 days after seeding (DAS) was counted 150g ai/ha, and delaying upto 15-30 DAS, the rates were increased upto 225-525g ai/ha. B. Flooded direct seeding and transplanting : The application rates were minimized 75g ai/ha at application timing upto 10 days after seeding/transplanting(DAS/T), 150g ai/haupto 15 DAS/T, and 225g ai/ha at later than 20 DAS/T, respectively.