• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.172-181
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• 2023

In order to raise the self-sufficiency rate of domestic forage and obtain informations necessary for production of high-quality winter forage, forage yield and feeding value were analyzed in the above-ground parts of a winter wheat 'Cheongwoo' harvested at five different growth stages, and the appropriate harvest time was determined. The yield increased until 30 days after heading, and then decreased afterwards. The proportion of spike in the above-ground part was less than 40% until 30 days after heading, but increased to more than 60% afterward. At 30 days after heading, the protein content and relative feed value (RFV) also reached peaks, while acid detergent fiber (ADF) and neutral detergent fiber (NDF) were low. The mineral nutrient contents are within the standard range required for feeding ruminant livestock or do not exceed the maximum allowable level. Therefore, the best time to harvest above-ground parts of a winter wheat 'Cheongwoo' for use as a forage for feeding ruminant livestock is around 30 days after heading, when considering forage yield and feed values. As a result it would match well in time with the transplantation of rice seedlings or the sowing of rice-alternative field crops in the double cropping system.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.2
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• pp.59-63
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• 1981

A field Experiment was conducted to evaluate a newly formulated N-K compound fertilizer (17-0-17) as a topdress ing fertilizer for rice in a poorly drained clayey soil, using Milyang 23 rice as test crop. The results are summarized as follows : 1. Both in terms of rice yield and uptake ratio of applied K, it was found that the tested N-K compound fertilizer is more effective than potassium chloride. 2. The detailied causes for the superiority of new compound fertilizer were not clarified.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.160-165
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• 1991

Growth performance of dry seeded paddy rice was studied at four N levels (10, 15, 20, and 25 kg/l0a) in tillage and no-tillage systems. Althougth the number of seedlings and maximum tillers tended to be higher and heading date was delayed by 2 days in tillage compared with those in no-tillage system, grainyield, yield components, lodging related characteristics, and N uptake were similar between two tillage ,systems. As N level increased, grain yield increased due to increased panicle number althougth the number of spikelets per panicle and percent ripended grains were similar and I, 000 grain weight decreased slightly. {Lodging index increased with increased N level due to higher plant height and decreased breaking strength and (culm base weigth, but lodging was not occurred in the field. Cellulose, hemicellulose, and lignin contents of culm base were similar among N levels. Concentration and uptake of N increased as N level increased.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.381-388
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• 1984

Addition of heavy textured red earth is being recommended to improve the texture and nutirent retention capacity of sandy soil in Korea. However, farmers are not favorable to this description because of high transportation cost and hard working. To solve this pending problem a field experiment was carried out to investigate the possibility of application of Zeolite as a foreign earth material to improve the physical and chemical characteristics of sandy soil. The experiment results suggested that Zeolite mixed with the basal N fertilizer would be substituted for other foreign earth materials in aspects of rice yield and nitrogen uptake of rice shoot. On the other hand, ammonium adsorption characteristics of soil and amendments were studied.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.901-910
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• 2003

The hydrologic behavior of paddy field depends largely on the irrigation and levee height management by farmers. The storage and drainage amount of paddy for storm events certainly influences the stream discharge. To understand the paddy storage effect during storm periods, a daily paddy water balance model embedding farmer's water management was developed by using 4 years (1996, 1997, 2001, 2002) field experimental data at 2 locations (Suwon and Yeoju) From the modeling, it was possible to simulate the daily ponding depth of paddy by treating paddy levee height and threshold pending depth indicating irrigation time as 10 days average parameters of the model. The storage amount(306.9 mm to 343.6 mm) showed little deviation to rainfall amount(425.1 mm to 850.8 mm).

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.11-21
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• 1989

This experiment was conducted at the IRRI experimental fram, Los Banos, Philippines to determine the effects of planting methods on lodging in rice, and to determine plant characteristics that induce lodging. Moderately lodging-susceptible IR36, lodging-susceptible line IR21820-3-2-2-3 and lodging-resistant IR8 and IR64 were tested. Except in IR8, lodging resistance of all test rices was higher when transplanted than when broadcast-seeded. Transplanted rices yielded higher than did broadcast-seeded rices except with broadcast-seeded IR8. Yield reduction due to lodging varied from 0.6 to 1.5 t/ha. Yield components and vegetative characteristics did not differ significantly between planting methods. However, higher culm K content was observed in transplanted rice, and it consequently increased lodging resistance. Phosphorus ans Si contents did not significantly affect culm strength.

• Journal of Korean Society of Rural Planning
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• v.12 no.2 s.31
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• pp.49-56
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• 2006

The application of domestic wastewater on rice paddies results in the accumulation of sodium(Na$^+$) to the soil. Excessive concentration of sodium may cause the deterioration of the physical characteristics of the soil, change in the osmosis of the soil, destruction of soil aggregates as well as ion toxicity due to sodium accumulation. Using domestic wastewater as irrigation water should be preceded by measures to prevent or control the soil salinization caused by sodium. Agricultural reuse of domestic wastewater were found not to cause serious problems with food safety due to heavy metals. However, pre-treatment using ultraviolet or ozone is recommended to reduce the number of bacteria and gem and for public health reasons. Using domestic wastewater has shown that reducing the standard application of chemical fertilizers by as much as 50% reduced the harvesting index by only 10%. This study has shown that it is feasible to reuse domestic wastewater on rice paddies. In order to facilitate the application, it is deemed necessary to establish wastewater treatment technologies in the future, to review criteria for recycling domestic wastewater for agricultural purposes such as conditions of soil and cropping system and to resolve conflicts with farmers and public health issues.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.1-11
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• 2001

Climate in the year of 2000 was characterized as a long severe drought in tile spring, unusually high and low temperature in summer, two times of typoons, and floods by heavy rains in fall. Rice leaf and panicle blast and bacterial grain rot occurred severely comparing with 1999 and Bipolaris leaf spot spread over tile country. Phytophthora blight and anthracnose in red-pepper became epidemic especially in the late season causing severe yield losses. Tomato fusaruim wilt, CGMMV, powdery mildew, and sudden wilt syndrom of cucurbits and strawberry powdery mildew were also severe in 2000. In garlic, sclerotium rot occurred severely mainly due to the frequent rainfalls in planting time and much snowfalls in 1999's winter. Spring potato had severe infection of viruses due to a long spring drought, and fall potato had high incidence of bacterial soft rot and bacterial wilt due to fall floods by heavy rains. In sweet potato fusarium wilt was the most severe as in other year. Disease incidence of apple and pear trees was rotatively mild compared with previous years. In wheat and barley, Gibberella petch rarely occurred because of spring drought.

• Korean Journal of Agricultural Science
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• v.8 no.1
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• pp.3-10
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• 1981

In order to analyze growth and yield of rice population at the stand point of productive ecology, productive structure and growth rate of rice plants and effects of their related factors were studied. The results obtained were summarized as follows: 1. High crop growth rate was maintained throughout growing season when rice plants grew in population compared to a single rice plant. Since crop growth rate in rice stands were also higher at ripening stage, higher yields were obtained. 2. Higher crop growth rate of rice plants in population was maintained by the increase of leaf area rather than by net assimilation rate. 3. As the overgrowth of upper leaves of plant population in some rice varieties transmission of light into lower leaves was inhibited and thus most of them were eventually died before flowering. 4. In the case of rice population, the ratio of productive organ to non-productive organ, light transmission rate and nitrogen contents of active leaf blade were lower than individual rice plants under isolated condition.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.311-316
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• 2013

This study was conducted to evaluate the efficacy of two different formulations and application timings of benzobicyclon+penoxsulam+pyrzaosulfuron-ethyl (BPP) in rice field. BPP granule (GR) and tablet (TB) controlled more than 90% of four weed species 10 and 15 days after sowing in direct seeding when compared with untreated control. BPP TB was highly effective to control herbicide resistant Scirpus juncoides and Monochoria vaginalis both 10 and 15 days after transplanting (DAT). BPP GR controlled 94.0 and 96.5% of S. juncoides and M. vaginalis, respectively 10 DAT, but its efficacy decreased to 88.5 and 49.8% respectively 15 DAT. When compared with untreated control, no visual injuries were detected at 255 and 510 g a.i./ha of BPP. The yield of rice increased in both BPP GR and TB in transplanting and direct seeding rice cultivation when compared with untreated control. Based on these data, early application (10 DAT) of BPP GR and TB can be applied to provide effective weed control, especially in the field infested with herbicide resistant weed species.