• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.336-336
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• 2011

본 연구에서는 강우시 경사지 밭에서 발생하는 토양유실량을 저감하기 위하여 지표피복재의 유무와 강우강도를 달리하여 실외인공강우 실험을 통하여 평가하였다. 인공강우 실험은 경사도 28%와 각 시험포는 $5\times30m$의 크기로 strawmat+PAM+sawdust, control(bare), strawmat+PAM, strawmat+PAM+rice husks를 4개 조성하고, 각 시험포는 하단부에 강우유출수를 채취할 수 있는 설비(flume)를 설치하였다. 대조구 실험을 위하여 각 시험포에서 발생하는 직접유출량과 유사량을 비교 분석하였다. 시험포의 토양은 양질사토로 일반 고랭지 밭의 흙과 동일한 성질을 가지고 있는 토양을 사용하였고, 지표 피복처리는 straw mat, saw dust, rice husk 그리고 PAM 등 4개의 재료를 사용하였다. 인공강우 실험은 1차 10월 18일, 2차 10월 24일, 3차 10월 30일, 4차 11월 7일로 총 21일간 각각 약 1주일의 간격을 두고 실시하였으며 인공강우 시험기의 강우강도는 각 31.1 ~ 44.4 mm/hr로 모의하였다. 연구결과 시험포에서 발생한 유출량은 지표피복을 하지 않은 대조구 시험포보다 지표를 피복한 시험포에서 약 15.7 ~ 19%의 감소한 것으로 나타났다. 유사량은 대조구 시험포보다 약 93.1 ~ 99.3% 감소한 것으로 나타났으며, 유출량과 유사량은 straw mat+PAM+sawdust와 straw mat+PAM+rice husk를 적용한 시험포에서 저감효과가 큰 것으로 나타났다. 이와 같이 지표피복처리는 강우가 발생하였을 때 강우타격력의 감소와 유출수의 유속감소 그리고 침투능을 증가하는 역할을 하여 경사지, 농경지 및 공사현장에서 토양 유실을 저감하며, 하천이나 강으로 유입되는 탁수량의 저감에 큰 효과가 있을 것으로 판단된다.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.75-80
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• 2001

This experiment was carried out to determine the effect of storing method and wrapping frequency on the quality of round baled rice straw silage at experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon fro 1999 to 2000. Storing methods consisted of erect and lay type, and wrapping frequencies were composed to 2, 4, 6, 8 and 10 film layers. there were no significant difference in feed value between storing methods, but acidity of lay type was significantly higher than that of erect type. According to the wrapping frequency, crude protein(CP) content of 2 film layers treatment was lowest during 6 month storing periods, and that of 4 film layers treatment was lowest during 10 month storing periods. The two film layers treatment which was stored for 10 month was impossible for ruminant to feed it, because it was rotten severely. Storing for 6 month, 2 film layers treatment represented highest pH value by 8.23 and storing for 10 month, 4 film layers treatment showed highest pH value by 7.17. Most of silage ranked grade 3 in quality grade. According to this experiment, it was recommended that application of round bale silage system to fresh rice straw should wrap above 4 film layers for 6 month, and above 6 film layers for 10 month storing periods.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.434-442
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• 1988

This study has been made to investigate the influences of organic matter on the soil composition, nitrogen fixing organism, soil enzyme activity and nitrogen fixing activity in the paddy rice rhizosphere when rice and barley straw were applied. The results are summarized as follows: 1. The pH in the submerged soil was increased from ear formation stage to harvesting. 2. In the rhizosphere, $Fe^{{+}{+}}$ content was decreased according to the growing stage, while increased in the nonrhizosphere. 3. In the initial stage, rhizosphere was higher than nonrhizosphere but in the late stage nonrhizosphere was higher than rhizosphere on the $NH_4-N$ content. 4. In the submerged soil, rhizosphere was higher than nonrhizosphere, on the concentration of glucose and pentose. 5. Changes of the number of nitrogen fixing organism in whole soil was not high. 6. Generally, rhizosphere was higher than nonrhizosphere on the soil enzyme activity such as phosphatase, ${\beta}$-glucosidase, and protease. 7. Acetylene-reducing activity was the highest in the tillering stage, and rhizosphere, Samgang (high-yielding variety) were higher than nonrhizosphere. Dongjin (general variety) respectively. 8. In the submerged soil applied barley straw, acetylene-reducing activity was slightly higher than rice straw in the initial stage.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.372-381
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• 1983

A laboratory experiment was performed to investigate the effects on redox potential of submerged soil by application of CNP herbicide (2, 4, 6-Trichlorophenyl-4-Nitrophenyl ether) with or without rice straw. Two soils, sandy loam and clay loam textured, were incubated for sixty days at a constant temperature, $25^{\circ}C$. Sampling and analysis of pH, Eh and nitrogen mineralization were carried out during the incubation. The results were summarized as follows. 1. The CNP application decreased redox potential and increased soil pH. The higher the concentration of applicated CNP was, the effects on soil Eh and pH were higher. When rice straw was used with CNP, the Eh of soil remarkably decreased, but seperating the individual effects of rice straw and CNP was impossible in this study. 2. Ammonification increased as the concentration of applied CNP increased regardless of rice straw application or not. It was higher in sandy loam soil than clay loam soil. 3. Nitrification decreased as the concentration of applied CNP increased, especially in the sandy loam soil. Rice straw application reduced nitrification.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.286-293
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• 1983

The glucose application remarkably increased the heterotrophic acetylene reducing activities during one month incubation. The amount of the increases varied between the soils. Application of rice straw brought about the significant increases during incubation time. Compost contained the largest amount of available-N among the C-sources, and thereby brought the smallest increase in all soils. The cumulative fixed nitrogen with application of rice straw at 30 days incubation in the three experimented soils were highest in Hwadong clay soil, i.e, $2.2mg^N/100g$, intermediate in Ratchaburi soil $0.85mg^N$, and least in Konosu soil $0.80mg^N/100g$. On the other hand, nitrogen fixing heterotrophic, bacteria, such as Clostridia, aerobes and anaerobes, were remarkably increased by application of rice straw while Azotobacter and Beijerinkia were not. The cumulative fixed nitrogen was more pronounced in the clay soil than in the coarse loamy soil. More pronounced nitrogen fixing activities in light condition(heterotrophic + photosynthetic) than that in dark(heterotrophic) condition have been observed both in the coarse loamy and clay soils. The nitrogen fixing ability of photosynthetic microbes in paddy soil is probably higher in coarse loamy soil than in clay soil.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.107-114
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• 2002

Rice straw silage added with apple pomace in different ratios were mixed with commercial concentrates and fed to Korean native goats in comparison to the corn silage mixed with the same content of commercial concentrates in whole diet as that of apple pomace added rice straw silage (rice straw : apple pomace = 100:0, 80:20, 60:40, 40:60). Dry matter intake, digestibilities of nutrients and nitrogen retention were investigated for the possibilities of application of agricultural by-products for the diets of Korean native goats. Crude protein contents of rice straw silage added with apple pomace were 6.3~7.3% and the contents of ADF, NDF and crude ash were highest in 100% rice straw mixed ratio (A) as 39.4, 61.6 and 8.9% respectively. Those were lower in corn silage (E) as 30.3, 53.4 and 4.9% respectively, however NSC content of corn silage was highest among the experimental treatments as 31.4%. Daily dry matter intakes per head and also per metabolic basal weight (DM g/kg of $BW^{0.75}$ were significantly (p<0.05) higher in D of the highest mixed ratio of apple pomace (605.3, 69.5g) than those of corn silage (E: 394.0, 46.8g). Daily live weight changes were significantly (p<0.05) higher in 40% (C: 16.7g) and 60% (D: 22.9g) apple pomace mixed ratios than 0% (A: 0.17g) and 20% (B: 4.3g) apple pomace mixed ratios. Digestibilities of dry matter and organic matter were higher in D and E than in A and B and those of ADF and NDF were higher in D as 50.2 and 57.4% respectively than the digestibilities in A, B and E. Nitrogen retention (g, %) was highest in D of the highest mixed apple pomace ratio (1.4g, 20.4%) however lowest in A (-0.3g, -7.75%).

• Korean Journal of Environmental Agriculture
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• v.2 no.1
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• pp.1-5
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• 1983

A study was undertaken to investigate the persistence of diazinon in two different soils under field conditions. Half-life of diazinon granule(5%) incorporated into soils at a rate of 0.15 ㎏ a.i./l0a was 11 and $9{\sim}12$ days in Suweon and Iri soil under field conditions, respectively. Diazinon residues in brown rice and rice straw harvested from Suweon field were also evaluated by scheduled application intervals. On the basis of maximum residue limit of diazinon in brown rice, it is recommended that the insecticide could be applied upto 15 days before harvest at the limit of 4 spraying times.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.47-54
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• 1979

A field experiment has been carried out to evaluate the residual effect of zinc fertilizers by rice plant grown under flooded conditions in the field. The results obtained are summarized as fellows ; Residual effect of zinc fertilizers on yields of rough and hulled grains showed slight increases. Effect of zinc application methods on yields of the grains were shown that zinc mixed treatment could be more effectively utilized than treatment of zinc on the soil surface. In case of levels of zinc application, 5 kg zinc per hectare represented high yields of the grains than those obtained from 10kg and 20kg zinc placement per hectare respectively. Regarding the form of zinc fertilizers, the urea-zinc complex showed less effective on yields of the grains than did the zinc sulfate. This phenomenon was consistent with the previous result. Yields of total zinc in rice plant grown on the rice straw added soils (Treatment No. 2 and 8) and the urea-zinc complex treated soil were increased markedly as compared to those data obtained from the previous year. The percentage of zinc derived from fertilizer decreased largely as compared to that of the first year crop. The yield of fertilizer zinc in rice plant decreased slightly in the most zinc treatments but in the case of treatments of zinc mixed with the straw added soil and the urea-zinc complex increased reversely as compared to the previous results. The mixed application of zinc with soil showed higher yield of fertilizer zinc than the soil surface placement. Approximately from 4.6 to 24.3 per cent of zinc taken up by rice plants were derived from the fertilizer zinc. Zinc fertilizer use efficiency ranged from 0.213 to 0.584 per cent when 5 kg zinc per hectare applied.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.894-898
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• 2012

본 연구는 밭에서 발생하는 비점오염물질을 저감하기 위하여 기존의 볏짚거적을 이용한 저감방법에 PAM과 Gypsum을 처리하였을 때, 표면유출량과 기저유출량, 유사량 그리고 탁도 등에 미치는 영향을 모의하고자 하였다. 연구 방법은 인공강우 시험기와 토양상자를 이용한 실내실험을 통하여 지표피복재의 종류와 강우강도 그리고 경사도에 따른 직접유출량과 유사량을 측정하고 비교하였다. 경사도 (10 %, 20 %)와 강우강도 (30 mm/hr) 그리고 지표피복재의 종류에 따라 실험처리를 하였으며, 지표피복재는 볏짚(Rice straw mat)+PAM (Polyacrylamide)+Gypsum, 볏짚+PAM+톱밥 (Sawdust)+Gypsum, 볏짚+PAM+왕겨 (Chaff)+Gypsum으로 구분하여 제작하였다. 실험 결과 볏짚을 이용한 다양한 피복소재를 이용해 지표를 피복할 경우, 대조구(나지)에 대비 유출수량, 토양유실 그리고 탁도 저감에 큰 효과가 있는 것으로 나타났다. 지표를 피복한 처리구의 평균 표면 유출수량은 대조구와 비교할 때 72~85.6 %가 저감되었다. 그러나 동일조건의 Gypsum을 첨가하지 않은 연구와 비교 시 Gypsum의 혼용으로 인한 효과는 크지 않은 것으로 나타났다. 세분화된 강우강도와 경사도 조건에 따른 실험이 필요하지만 본 연구의 결과에 기초할 때, 지표의 피복과 토양개량제를 첨가하는 방법은 강우 시 발생하는 표면유출수와 유사 그리고 탁수를 저감시킬 수 있는 최적영농관리방법 (Best management practice)의 하나로 판단된다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.53-53
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• 2022

Modem agricultural production needs to provide sustainable management practices that are eco-friendly and low cost. Plant extracts are a cost-effective and environmentally friendly alternative to synthetic plant growth regulators. This study was therefore carried out to investigate the effects of various plant extracts produced using different extraction methods on the vegetative growth of rice under laboratory and greenhouse conditions. For this study, seventeen plant extracts were made from plant species such as leaves of M. arvense, C. asiatica, M. oleifera, V. radiata, V. unguiculate, P. guajava, A. vera, and A. tuberosum, aboveground plant parts of C. rotundus, M. sativa, and P. frutescens, roots of R. undulatum, tubers of A. sativum, leaves and stems of G. max (cv. Taegwang) as well as rice straw and hulls (cv. Hopyeong). As a test crop, we applied these extracts to rice plants. For the purpose of making our extracts, some plant materials and species were collected in fields and others were purchased from Chonnam Hanyaknonghyup Cooperation (South Korea). Leaves, roots, and aboveground plant parts of plant species were dried, ground, extracted (water, boiling water and ethanol) and fermented. Rice growth promotion effects were determined using plant extracts at 0, 0.05, 0.1, 0.5, and 1% concentrations under petri dish conditions. Seven selected plant extracts were applied to rice seeds with soil drench application or seedling at 3-4 leaf stages with soil and foliar applications under greenhouse conditions. For comparison with extracts, we used urea at 0.6%. Of the 17 water extracts used in this study, 10 extracts reduced rice growth, but the other 7 extracts (P. guajava, A. vera, A. tuberosum, M. sativa, A. sativum, and G. max) increased growth by 40-60% on compared to the control in Petri dish bioassay. Thus, these 7 extracts were selected for further study. Under greenhouse conditions, rice growth also increased by 20-40% when the same 7 extracts were applied to rice seeds using soil drench application. Furthermore, at the 3-4 leaf stage rice growth also increased 30-80% or 30-60% when the same 7 extracts were applied using soil and foliar applications. Overall, the 7 extracts produced higher rates of growth promotion when soil drench application was used than when foliar application was used. In the case of boiling water and ethanol extracts, rice growth increased only 20% in response to both soil drench and foliar application of the same 7 extracts. Rice growth promotion was greater when extracts were produced using water extraction method than boiling water and ethanol extraction methods. Most notably, the 7 water extracts used in this study produced higher rates of growth promotion than urea at 0.6% which is typically used for crop growth promotion. Overall, the 7 water extracts when applied using soil drenching method can be used as effective growth promotors of rice in organic agriculture.