• Title/Summary/Keyword: nitrogen fertilizer rate

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Analysis of Nutrient Cycling Structure of a Korean Beef Cattle Farm Combined with Cropping as Affected by Bedding Material Types (깔개물질의 종류에 따른 한우-경종 결합 농가의 양분순환 구조 분석)

  • Lim, Sang-Sun;Kwak, Jin-Hyeob;Park, Hyun-Jung;Lee, Sun-Il;Lee, Dong-Suk;Kim, Yong-Soon;Yun, Bong-Ki;Kim, Sun-Woo;Choi, Woo-Jung
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.5
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    • pp.354-361
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    • 2008
  • In this study, we analyzed nutrient cycling structure of a small farm (cattle of 100 heads and arable lands of 2.5 ha) in Jeonnam province to investigate the effects of nutrients input by the addition of bedding materials (sawdust and rice hull) and nutrients loss before the application to the soils (the period during manure storage in the feedlot and composting process) on nutrient cycling structure. Sawdust and rice hull added as bedding materials increased N by 1.6% and 14.2% and $P_2O_5$ by 3.1% and 27.4%, respectively, relative to the amount of nutrients produced by excretion. This result suggests that the addition of nutrients via bedding materials should be considered for better estimation of nutrient balance. The most significant characteristics of the nutrient cycling structure was loss of mass and nutrients during the storage (21 days) and composting period (90 days). During this period, 78.4% of N and 9.5% of $P_2O_5$ was lost from sawdust compost; meanwhile, the percentages of loss for rice hull compost were 81.6% and 10.3%, respectively. A lower percentage of nutrients loss in sawdust compost than that in rice hull compost was attributed to the relatively slow decomposition rate of organic materials in the sawdust compost which has higher C/N ratio and lignin contents. Therefore, it was concluded that estimation of nutrient balance should be conducted based on nutrient contents in the final compost being applied to the lands rather than the amount of nutrients contained in the livestock excretion. In addition, the effects of bedding materials on nutrient losses should be also taken into account.

Influence of Water Temperature on the Changes of Soil and Plant Nutrient of Paddy Rice (관개수온(灌漑水溫)의 차이(差異)가 토양(土壤) 및 수도체내(水稻體內) 양분변동(養分變動)에 미치는 영향(影響))

  • Kim, L.Y.;Min, K.B.;Jo, I.S.;Ju, N.S.;Um, K.T.
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.3
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    • pp.247-253
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    • 1985
  • In order to investigate the effects of water temperature on chemical properties of soil and nutrient uptake of rice plant, four varieties of rice were cultivated in a field where water temperature range was $17.3-23.0^{\circ}C$ and plant samples were taken at three growing stages and were analyzed in detail. The results were summarized as follows: 1. Organic matter content and pH of surface soil were showed no differences while the contents of $P_2O_5$ and $SiO_2$ were increased and potassium was decreased as the water temperature increased. 2. The amounts of nutrient uptake were related to the water temperature and the total nutrient contents of rice plants at harvesting stage were in order of $SiO_2$ > $K_2O$ > T-N > $P_2O_5$ > MgO. The rate of $SiO_2$/N and $K_2O$/N of rice plants grown at water temperature $23.0^{\circ}C$ were over two times to those of the water temperature $17.3^{\circ}C$. 3. Nutrient contents of rice plants showed a increasing tendency as increasing the water temperature. However, nutrient contents such as T-N at whole period, $P_2O_5$ at heading and harvesting stage, and $K_2O$ at heading stage were higher at low water temperature than those of high water temperature. 4. Most of nitrogen was translocated and accumulated in grain, potassium in straw respectively. All nutrients translocated to grain more easily as the water temperature increased.

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Nitrogen and Phosphorus Loss with Runoff and Leachate from Soils Applied with Different Agricultural By-product Composts (부산물 퇴비를 시용한 토양에서 표면유거와 용탈에 의한 질소와 인의 유실)

  • Park, Chol-Soo;Joo, Jin-Ho;Lee, Won-Jung;Yoo, Kyung-Yoal;Yang, Jae-E;Ok, Yong-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.38 no.6
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    • pp.307-312
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    • 2005
  • Since alpine upland in Pyungchang-gun has been typically applied every two or three years with saprolite, agricultural by-products are inputted to raise soil properties. Therefore, the effect of saprolite application on water quality in runoff and leachate should be monitored. To investigate water quality in runoff and leachate with various treatments of agricultural by-product, lysimeter with dimension of $0.85m{\times}1.75m{\times}0.30m$ was installed in Kangwon National University. Control, mixed compost with cow, chicken and sawdust by-product (CCSC), chicken manure by-product compost (CC), food waste by-product compost (FWC), and beer sewage sludge by-product compost (BSSC) at the rate of $10Mg\;ha^{-1}$ were mixed with soil in 25 cm depth, and water qualities in runoff and leachate were monitored from Jun. 4, 2004 to Oct. 18, 2004. EC ($0.8-2.2dS\;m^{-1}$) and concentrations of total N ($25-75mg\;L^{-1}$) and total P ($0.12-0.43mg\;L^{-1}$) were highest in both runoff and leachate of CC treatment. EC values in CC and FWC treatments continuously increased during lysimeter experiment, while total N and total P concentrations continuously decreased. Average total N concentrations in runoff taken from CCSC, FWC and BSSC treatments were 41, 34 and $37mg\;L^{-1}$, and in leachate were 35, 28 and $34mg\;L^{-1}$, respectively. Average total P concentrations were not different with different treatments. EC values in leachate were higher than those in runoff, and total N concentrations in runoff were higher than those in leachate.

Effects of Application Rates of Liquid Pig Manure on Rice Growth, Quality and Soil Properties (돈분액비의 시용수준이 벼 생육과 품질 및 토양에 미치는 영향)

  • Ryoo, Jong-Won
    • Korean Journal of Organic Agriculture
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    • v.22 no.4
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    • pp.667-682
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    • 2014
  • The effects of liquid pig manure (LM) on the yield and quality of rice as well as soil chemical properties were determined in the field of sandy loam soil under the different fertilizer management. Treatments consisted of 100%, 130% and 160% N application rates of liquid manure as calculated on the basis of the recommended rate of nitrogen (9 kg N/10a) for rice cultivation. Chemical fertilizer (CF) was used as control. Concentrations of T-N and T-P in paddy water were measured by 5-day intervals up to 20days after application. LM treatments significantly increased T-N concentrations in paddy water proportionally with increasing rates of LM (13.2 to 25.7 mg/L). Similarly Total-P content in paddy water was increased right after LM applications but was well below the quality standard of wastewater and manure. Plant height and tillers in 100% and 130% N LM treatments were lower than those in CF control. In the 160% LM treatment, however, plant height and numbers of tillers were higher than those in the CF control. Yields in 100% LM and 160% LM plots were decreased by 3 and 5%, respectively, as compared with 422 kg per 10a in the CF plot. Rice protein contents were similar between 100% LM and CF control (about 6.8%) but it was increased to 7.2% and 7.7% in 130% LM and 160% LM treatments, respectively. Toyo-taste value in the 100% LM treatment was higher than in CF control plot. The proportions of perfect grain of the brown rice were lower in 130% LM and 160% LM treatments than that in CF control. Soil organic matter content, heavy metal and exchangeable cations were highest in the 160% LM plot. Thus considering yield and quality of rice and heavy metals contents in soil, 130% N basal application of liquid manure can be recommended for rice cultivation in this experiment.

A Study on the Improvement of Treatment Efficiency for Nitrogen and Phosphorus in Livestock Treatment System Using Constructed Wetlands (인공습지 축산폐수처리시스템에서 질소 및 인 처리효율 향상 방안)

  • Seo, Dong-Cheol;Park, Jong-Hwan;Kim, Ah-Reum;Kim, Sung-Hun;Lee, Seong-Tea;Jeong, Tae-Uk;Choi, Jeong-Ho;Lee, Sang-Won;Kim, Hyun-Ook;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.3
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    • pp.434-441
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    • 2011
  • To improve T-N and T-P removal efficiencies, removal efficiencies of pollutants in full-scale livestock wastewater treatment plant by natural purification method with water plant filtration and activated sludge beds were investigated under different re-injection rates and injection methods of livestock wastewater. The removal rates of COD, SS, T-N, and T-P in effluent in full-scale livestock wastewater treatment plant were in the order of 30% < 70% ${\leq}$ 100 % at different re-injection rates. The removal rates of pollutants in effluent in full-scale livestock wastewater treatment plant were higher as re-injection rate of livestock wastewater increased. Removal rates of COD, SS, T-N, and T-P by continuous injection were slightly higher than those by intermittent injection method in full-scale livestock wastewater treatment plant. Removal rates of COD, SS, T-N, and T-P by continuous injection method in full-scale livestock wastewater treatment plant with water plant filtration and activated sludge beds were 99.5, 99.8, 99.0 and 99.8%, respectively.

Plant Growth Promoting Effect and Antifungal Activity of Bacillus subtilis S37-2 (Bacillus subtilis S37-2 균주의 항진균활성 및 식물생육촉진 효과)

  • Kwon, Jang-Sik;Weon, Hang-Yeon;Suh, Jang-Sun;Kim, Wan-Gyu;Jang, Kab-Yeul;Noh, Hyung-Jun
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.6
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    • pp.447-453
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    • 2007
  • With a broad objective for the development of microbial based fertilizers, a total of 373 strains were isolated from rhizoplane and rhizosphere of pepper, tomato, lettuce, pasture, and grass. The efficacy of the isolates to augument overall plant growth was evaluated. After screening for their plant growth promotion and antagonistic properties in vitro efficient strains were further selected. The most efficient strains was characterized by 16S rRNA gene sequences and biochemical techniques and was designated as Bacillus subtilis S37-2. The strains facilitated plant growth and inhibited the plant phathogenic fungi such as Fusarium oxysporum (KACC 40037, Rhizoctonia solani (KACC 40140), and Sclerotinia sclerotiorum (KACC 40457). Pot based bioassay using lettuce as test plant was conducted by inoculating suspension ($10^5$ to $10^8cells\;mL^{-1}$) of B. subtilis S37-2 to the rhizosphere of lettuce cultivated in soil pots. Compared with non-inoculated pots, marked increase in leaf (42.3%) and root mass (48.7%) was observed in the inoculation group where the 50ml of cell mixture ($8.7{\times}10^8cells\;ml^{-1}$) was applied to the rhizosphere of letuce either once or twice. Antagonistic effects of B. subtilis S37-2 strain on S. sclerotiorum (KACC 40457) were tested. All the tested lettuce plants perished after 9 days in treatment containing only S. sclerotiorum, but only 17% of lettuce was perished in the inoculation plot. B. subtilis grew well in the TSB culture medium. The isolates grew better in yeast extracts than peptone and tryptone as nitrogen source. The growth rate was 2~4 times greater at $37^{\circ}C$ as compared with $30^{\circ}C$ incubation temperature. B. subitlis S37-2 produced $0.1{\mu}g\;ml^{-1}$ of IAA (indole 3-acetic acid) in the TSB medium containing L-tryptophan($20mg\;L^{-1}$) in 24 hours.

The Growth Performances and Soil Properties of Planted Zelkova serrata Trees according to Fertilization in Harvested Pinus rigida Plantation over 6 Years after Planting (조림지 시비 처리에 따른 리기다소나무 벌채지 내 식재 6년 후 느티나무 조림지 토양 및 조림목 생장 특성)

  • Yang, A-Ram;Cho, Min Seok
    • Journal of Korean Society of Forest Science
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    • v.108 no.1
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    • pp.29-39
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    • 2019
  • The objective of this study was to suggest a suitable amount of fertilizer using the changes in growth performances and soil properties for improving survival and quality of Zelkova serrata trees in a harvested Pinus rigida plantation. One-year-old containerized seedlings of Z. serrata were planted with the density of 3000 seedlings $ha^{-1}$ in end of March 2011 at Gwangneung experimental forest, Pocheon. Solid compound fertilizer (N:P:K=3:4:1) were applied yearly in three amounts (control: no fertilization, F1: $180kg\;ha^{-1}$, and F2: $360kg\;ha^{-1}$) every May from 2011 to 2013. We analyzed soil properties before (2011) and after (2012 and 2017) fertilization. And we measured the root collar diameter and height of Z. serrata trees from 2011 to 2016, and then calculated H/D ratio and stem volume. Soil properties at Z. serrata plantation did not show difference according to fertilization level in every investigation year. As time passed after planting, however, concentrations of total nitrogen and available phosphorus were increased from decreased. The growth of root collar diameter, height and stem volume of Z. serrata trees at F2 plot were significantly higher those at the other plots after only 2 years of fertilization. Because Z. serrata tree demand to more nutrient during the early growing period. The survival rate of Z. serrata trees at control plot was significantly lower than that at the other plots. This might be due to Z. serrata trees at control plot had not the upper hand from competition with vegetation at the early in planting. However, the growth of height and stem volume of Z. serrata trees between F1 and F2 plots did not show difference over 6 years after planting. Consequently, we could suggest that Z. serrata trees need to F1 fertilization level for considering improving survival and quality of Z. serrata trees and economical efficiency of plantation managements after harvesting P. rigida plantation.

The Behaviors of Phosphorus-32 and Ptoassium-42 under the Control of Thermoperiod and Potassium Level (가리(加里)와 온도주기성(溫度週期性)이 고구마 생육(生育) 및 인(燐)-32, 가리(加里)-42 동태(動態)에 미치는 영향(影響))

  • Kim, Y.C.
    • Korean Journal of Soil Science and Fertilizer
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    • v.1 no.1
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    • pp.89-115
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    • 1968
  • 1. The experiment was carried out for investigating the interaction between potassium nutrition and thermoperiod (as an environment regulating factor) in relation to behaviors of several nutrients including phosphorus-32 and Potassium-42 in IPOMOEA BATAS. 2. To obtain same condition to trace the behaviors of phosphorus and potassum-42 they were simultaneously incorporated to roots. The determination of each CPM by counting twice with adequate interval and calculating true CPM of each isotope according to different half-life, was carried out with satisfactory. 3. Some specific symptoms i.e, chlorosis and withering of growing point under the condition of lower potassium level were found and was accelerated by the low night temperature. 4. A manganese shortage in growing point of the lower potassium level was found by activiation analysis and very low distribution ratio of phosphorus-32 and potassium-42 in the growing point of the lower potassium level was manifested, though the contents of nitrogen, phosphorus, potassium, sodium and magnesium were not in great difference. 5. In addition to the low water content with appearence of "hard", shorterning internode and lower ratio of roots to shoot as well as the symptoms of potassium deficiency such as brown spot in leaf blade and necrosis of leaf margin were appeared at later stage of experiment at the lower potassium level. 6. Very stimulating vegetative growth, e.g, large plant length, leaf expansion, increasing node number and fresh weight as well as high ratio of roots to shoot, high water content was resulted in the condition of higher potassium level. 7. A specific interaction between higher potassium level and thermoperiod was found, that is, the largest tuber production and the largest ratio of roots to shoot were resulted in the combined condition of higher potassium level and constant temperature while the largest plant length, fresh weight etc. i.e. the most stimulative vegetative growth was resulted in the combined condition of higher potassium level and low night temperature. 8. Comparatively low water content in the former condition of stimulative tuber production was resulted(especially at the tuber thickening stage), while high water content in the latter condition of stimulative vegetation was resulted though the higher potassium level made generally high water contents. 9. The nitrogen contents of soluble and insoluble did not make distinct difference between the lower and higher potassium level. 10. Though the phosphorus contents were not distinctly different by the potassium level, the lower potassium level made the percentage of phosphorus increased at tuber forming stage accumulating more phosphorus in roots, while the higher potassium level decreased percentage of phosphorus at that stage. 11. The higher potassium level made distinctly high potassium contents than the lower potassium level and increased contents at the tuber forming stage through both conditions. 12. The sodium contents were low in the condition of higher potassium level than the lower potassium level and decreased at tuber forming stage in both conditions, on the contary of potassium. 13. Except the noticeable deficeney of manganese in the growing point of the lower potassium level, mangense and magnesium contents in other organs did not make distinct difference according to the potassium level. 14. Generally more uptake and large absorption rate of phosphorus-32 and potassium-42 were resulted at the higher potassium level, and the most uptake, and the largest absorption rate of phosphorus and potassium-42 (especially potassium-42 at tuber forming stage) were resulted in the condition of higher potassium level and constant temperature which made the highest tuber production. 15. The higher potassium level stimulated the translocation of phoshorus-32 and potassium-42 from roots to shoots while the lower potassium level suppressed or blocked the translocation. 16. Therefore, very large distribution rate of $p^{32}$, $K^{42}$ in shoot, especially, in growing point, compared with roots was resulted in the higher potassium level. 17. The lower potassium level suppressed the translocation of phosporus-32 from roots to shoot more than that of potassium-42. 18. The uptake of potassium-42 and translocation in IPOMOEA BATATAS were more vivid than phosphorus-32. 19. A specific interaction between potassium nutrition and thermoperiod which resulted the largest tuber production etc. was discussed in relation to behaviors of minerals and potasium-42 etc. 20. Also, the specific effect of the lower and higher potassium level on the growth pattern of IPOMOEA BATATAS were discussed in relation to behaviors of minerals and isotopes. 21. An emphasize on the significance of the higher potassium level as well as the interaction with the regulating factor and problem of potassium level (gradient) for crops product ion were discussed from the point of dynamical and variable function of potassium.

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Study on the Technological System of the Cooperative Cultivation of Paddy Rice in Korea (수도집단재배의 기술체계에 관한 연구)

  • Min-Shin Cho
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.8 no.1
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    • pp.129-177
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    • 1970
  • For the purpose of establishing the systematized technical scheme of the cooperative rice cultivation which has most significant impact to improve rice productivity and the farm management, the author have studied the cultivation practices, and the variation of rice growth and yield between the cooperative rice cultivation and the individual rice cultivation at random selected 18 paddy fields. The author also have investigated through comparative method on the cultivation practices, management, organization and operation scheme of the two different rice cultivation methods at 460 paddy fields. The economic feasibility has been ana lysed and added in this report. The results obtained from this study are summarized as follows; 1. In the nursery, the average amount of fertilizer application, especially, phosphate and potassium, and the frequency of chemicals spray for the disease, insect and pest control at the cooperative rice cultivation are significantly higher than those of the individual rice cultivation. 2. The cultivation techniques of the cooperative rice farming after the transplanting can be characterized by a) the earlier transplanting of rice, b) the denser hills per unit area and the lesser number of seedlings per hill, c) the application of larger quantities of fertilizer including nitrogen, phosphate and potassium, d) more divided application of fertilizers, split doses of the nitrogen and potassium, e) the increased frequencies of the chemicals spray for the prevention of disease, insect and pest damages. 3. The rate of lodging in the cooperative rice cultivation was slightly higher than that of the individual rice cultivation, however, the losses of rice yield owing to the occurrence of rice stem borer and grass leaf roller in the cooperative rice cultivation were lower than that of the individual rice cultivation. 4. The culm length, panicle length, straw weight and grain-straw ratio are respectively higher at the cooperative rice cultivation, moreover, the higher variation of the above factors due to different localities of the paddy fields found at the individual rice cultivation. 5. The number of panicles, number of flowers per panicle and the weight of 1, 000 grains, those contributing components to the rice yield were significantly greater in the cooperative rice cultivation, however, not clear difference in the maturing rate was observed. The variation coefficient of the yield component in the cooperative cultivation showed lower than that or the individual rice cultivation. 6. The average yield of brown rice per 10 are in the cooperative rice cultivation obtained 459.0 kilograms while that of the individual rice cultivation brought 374.8 kilograms. The yield of brown rice in the cooperative rice cultivation increased 84.2 kilogram per 10 are over the individual rice cultivation. With lower variation coefficient of the brown rice yield in the cooperative rice cultivation, it can be said that uniformed higher yield could be obtained through the cooperative rice cultivation. 7. Highly significant positive correlations shown between the seeding date and the number of flowers per panicle, the chemical spray and the number of flowers per panicle, the transplanting date and the number of flowers per panicle, phosphate application and yield, potassium application and maturing rate, the split application of fertilizers and yield. Whilst the significant negative correlation was shown between the transplanting date and the maturing rate 8. The results of investigation from 480 paddy fields obtained through comparative method on the following items are identical in general with those obtained at 18 paddy fields: Application of fertilizers, chemical spray for the control of disease, insects and pests both in the nursery and the paddy field, transplanting date, transplanting density, split application of fertilizers and yield n the paddy fields. a) The number of rice varieties used in the cooperative rice cultivation were 13 varieties while the individual rice cultivation used 47 varieties. b) The cooperative rice cultivation has more successfully adopted improved cultivation techniques such as the practice of seed disinfection, adoption of recommended seeding amount, fall ploughing, application of red soil, introduction of power tillers, the rectangular-type transplanting, midsummer drainage and the periodical irrigation. 9. The following results were also obtained from the same investigation and they are: a) In the cooperative rice cultivation, the greater part of the important practices have been carried out through cooperative operation including seed disinfection, ploughing, application of red soil and compost, the control of disease, insects and pests, harvest, threshing and transportation of the products. b) The labor input to the nursery bed and water control in the cooperative rice cultivation was less than that of the individual rice cultivation while the higher rate of labor input was resulted in the red soil and compost application. 10. From the investigation on the organization and operation scheme of the cooperative rice cultivation, the following results were obtained: a) The size of cooperative rice cultivation farm was varied from. 3 ha to 7 ha and 5 ha farm. occupied 55.9 percent of the total farms. And a single cooperative farm was consisted of 10 to 20 plots of paddies. b) The educational back ground of the staff members involved in the cooperative rice cultivation was superior than that of the individual rice cultivation. c) All of the farmers who participated to the questionaires have responded that the cooperative rice cultivation could promise the increased rice yield mainly through the introduction of the improved method of fertilizer application and the effective control of diseases, insects and pests damages. And the majority of farmers were also in the opinion that preparation of the materials and labor input can be timely carried out and the labor requirement for the rice cultivation possibly be saved through the cooperative rice cultivation. d) The farmers who have expressed their wishes to continue and to make further development of the cooperative rice cultivation was 74.5 percent of total farmers participated to the questionaires. 11. From the analysis of economical feasibility on the two different methods of cultivation, the following results were obtained: a) The value of operation cost for the compost, chemical fertilizers, agricultural chemicals and labor input in the cooperative rice cultivation was respectively higher by 335 won, 199 won, 288 won and 303 won over the individual rice cultivation. However, the other production costs showed no distinct differences between the two cultivation methods. b) Although the total value of expenses for the fertilizers, agricultural chemicals, labor input and etc. in the cooperative rice cultivation were approximately doubled to the amount of the individual rice cultivation, the net income, substracted operation costs from the gross income, was obtained 24, 302 won in the cooperative rice cultivation and 20, 168 won was obtained from the individual rice cultivation. Thereby, it can be said that net income from the cooperative rice cultivation increased 4, 134 won over the individual rice cultivation. It was revealed in this study that the cooperative rice cultivation has not only contributed to increment of the farm income through higher yield but also showed as an effective means to introduce highly improved cultivation techniques to the farmers. It may also be concluded, therefore, the cooperative rice cultivation shall continuously renovate the rice production process of the farmers.

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Physiological studies on the sudden wilting of JAPONICA/INDICA crossed rice varieties in Korea -I. The effects of plant nutritional status on the occurrence of sudden wilting (일(日). 인원연교잡(印遠緣交雜) 수도품종(水稻品種)의 급성위조증상(急性萎凋症狀) 발생(發生)에 관(關)한 영양생리학적(營養生理學的) 연구(硏究) -I. 수도(水稻)의 영양상태(營養狀態)가 급성위조증상(急性萎凋症狀) 발생(發生)에 미치는 영향(影響))

  • Kim, Yoo-Seob
    • Korean Journal of Soil Science and Fertilizer
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    • v.21 no.3
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    • pp.316-338
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    • 1988
  • To identify the physiological phenomena on the sudden wilting of japonica/indica crossed varieties, Pot experiment was carried out under the heavy N application with various levels of potassium in Japan. The results obtained are as follows. 1. Sudden wilting was occurred in both varieties used, Yushin and Milyang 23. The former showed a higher degree than the latter. 2. Sudden wilting was occurred into two types, one at early ripening stage and the other at late ripening stage. The former type was found in the field with low potassium supply and the latter was seemed to be related to varietal wilting tolerence. 3. By the investigation of concerning the effective tillering rate and the change of dry weight of each organ at the heading stage, it was inferred that the growth status from young panicle formation stage to heading stage were related to sudden wilting tolerence. 4. Manganese content at heading stage, ratio of Fe/Mn and Fe. Fe/Mn in stern at late ripening stage and $K_2$ O/N ratio of stem at harvesting stage were recognized as the specific factors in connection with sudden wilting. Mn content in the sudden wilting rice plant was already in creased remarkably at heading stage. In relation to root age and absoption characteristics of Mn, the senility of root before heading stage was inferred as the cause of increase the value of Fe/Mn or Fe. Fe/Mn. 5. The $K_2$ O/N ratio of culm at harvesting stage was lower in upper node than lower node in relation to sudden wilting. And it was well accordance with the fact that the symptoms of sudden wilting proceeded from upper leaf to lower leaf. These phenomenon was different from the usual one that the effect of potassium deficiency was more remarkable in lower node than upper node. 6. All varieties which have a condition of potassium deficiency have a high degree of nitrogen content of leaves at heading stage and the $K_2$ O/N ratio of each organ was low, Especialy, $K_2$ O/N ratio is much lower in sheath and culm than leaves.

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