• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.132-136
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• 2002

The rice straw managements are essential for maintaining soil fertility as well as reducing chemical fertilizer application in paddy field. A field experiment was conducted on moderately well draining alluvial paddy soil to investigate the decomposition pattern of rice straw. The mesh bags containing the rice straw harvested in the previous year were placed at soil surface and buried into around 10cm depth and recovered periodically for determining the straw decomposition. Pot experiments were conducted to investigate the fates of N released from $^{15}$ N-labeled rice straw under different levels of N fertilizer application. The overall decomposition patterns of rice straw were similar for the two incorporation depths in transplanted paddy field. The straw incorporated at transplanting date showed weight loss of about 50%, 70% and 90% after 2 months, 5 months, and 2 years, respectively. The decompositions of straw cell wall components showed somewhat different pattern. The decompositions of cellulose and silica were similar to that of dry weight while the decomposition of lignin was slower than that of cellulose and silica. N was released from rice straw 42% and 65 % of the initial N after one month and after five months, respectively. P release was faster than N release. Recoveries of rice straw-$^{15}$ N by rice plants were 10.2, 13.4 and 14.9% in 0, 120 and 240 mg N pot$^{-1}$ , respectively. Soil recoveries of rice straw $^{15}$ N were 17.3, 20.6 and 18.9% in 0, 120 and 240mg N pot$^{-1}$ , respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.26-27
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• 2015

The purpose of this study was to investigate the compressive strength property into concrete using rice straw ash.. In an effort to evaluate the effects of rice straw ash as mineral admixture, rice straw ash was mixed with cement at the mixture ratio of 0, 5, 10 and 15% relative to the cement weight. When the mixture ratio of rice straw ash was 10%, the highest compressive strength was observed, while the strength tended to decrease when the mixture ratio of rice straw ash was 15% even if it exhibited higher compressive strength than the plain. And it was observed that compressive strength of concrete containing rice husk ash was a similar a compressive strength of concrete containing silica fume.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.253-253
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• 2010

Rice straw was pretreated with aqueous ammonia in order to enhance enzyme digestibility. Soaking in ammonia aqueous (SAA) was conducted with 15% ammonia, at $60^{\circ}C$. for 24 h. Optimization of both saccharification conditions and enzyme loading of SAA rice straw was carried out. Especially enzyme loading test was performed using statistical method. Moreover proton beam irradiation (PBI) was also performed to overcome the problem which inhibit the enzyme digestibility at 1-25 kGy doses with 45 MeV of beam energy. Optimal condition for enzymatic saccharification was follows; pH 4.8, $50^{\circ}C$, 60 FPU of enzyme activity, 1:4 ratio of celluase and ${\beta}$-glucosidase. Also, optimal doses of PBI on rice straw and SAA-treated rice straw for efficient sugar recovery were found to be 3 kGy, respectively. When saccharification was performed with optimal condition, glucose conversion yield was 89% of theocratical maximum in 48 h, and 3 kGy of PBI was applied to SAA-treated rice straw, approximately 90% of the theoretical glucose yield was obtained in 12 h. The results of X-ray diffractometry (XRD) support the effect of both SAA and PBI on sugar recovery, and scanning electron microscopy (SEM) images unveiled the physical change of the rice straw surface since rugged rice straw surface was observed.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.309-318
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• 2007

The effects of supplementation of organic citrus on the quality of rice straw silage was investigated in this study. The aim of the study was to improve the quality of rice straw silage using agricultural by-products and therefore to secure the good quality forage sources. Firstly, looking at chemical composition of citrus added rice straw silage, crude protein content appeared improved with the addition of citrus to rice straw silage compared to control while NDF and ADF contents decreased. pH of the silages were different between control(4.39) and treatments$(3.47\sim3.53)$. Lactic acid content was higher in citrus added silage(4.87mM) than in control (3.65mM). External quality of the silages was also better in citrus added silage when citrus added at the equal ratio with rice straw(1 : 1). This trend was the same as with pH and lactic acid content. Propionate was significantly higher in citrus addd silage but butyrate was significantly lower. DM and NDF disappearance rates in the rumen were highest when citrus added at the equal ratio with rice straw(1:1). In conclusion, supplementation of citrus to rice straw silage with equal ratio contributed the best to the improvement of the quality of silage and it may have been due mainly to abundant content of non-structural carbohydrate in citrus.

• Analytical Science and Technology
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• v.5 no.1
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• pp.1-5
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• 1992

The adsorption amount of petroleum oil on XAD-4, XAD-7 and replacement adsorbents as rice bran, rice straw and sawdust were studied by using batch method measured in the optimum adsorption condition. The adsorption capacity of rice bran and rice straw of petroleum oil were excellent as well as adsorption ability about 50% of XAD resins and adsorption capacity of their replacement adsorbents were increased with optimum condition that pyrolysis time was 30 min. at $200^{\circ}C$. Adsorption ability of sawdust was very weak on the 30% MeOH aqueous medium but adsorption ability was range of about 50% of XAD resin's adsorption capacity on the 0.5M NaCl aqueous medium. Adsorption ability of rice bran and rice straw showed the same adsorption capacity even if difference external structure. Therefore, showing that rice bran and rice straw were have to good adsorption ability as replacement adsorbent for XAD resins.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1200-1204
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• 1999

Two experiments were conducted to study the effect of urea treatment of rice and wheat straw on feed intake, dry matter (DM) digestibility and milk yield of lactation buffaloes in their late lactation under farmers' management conditions in the western hills of Nepal during 1995 and 1997. Dry matter intake (DMI) from urea treated rice and wheat straw was not improved significantly (p<0.05) nor the total DMI of the lactating buffaloes was improved significantly. However, feeding urea treated rice straw increased straw DMI by 14.2% and total DMI by 10.63% units over the untreated rice straw. Similarly, the increase in straw and total DMI were 20.18 and 17.40% units over the untreated wheat straw fed animals. Although there was no significant effect of urea treatment of both straw on DM digestibility, it was higher for treated than untreated straw at all locations. An overall increment of 18.1% units for rice straw and 13.3% units for wheat straw was observed. There was a significant effect (p<0.01) of feeding urea treated rice and wheat straw on the milk yield of lactating buffaloes during late lactation under farmers conditions. Post experiment milk yield was also significantly (p<0.05) higher for the animals fed treated straw in both the experiments. Buffalo milk yield was also significantly affected by breed (p<0.01), location (p<0.01) and parity (p<0.01) of the animals. General response of the farmers about the technology and their observed effect on animal performance was also very positive.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.191-196
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• 1999

In rice-barley cropping systems, efficient utilization of barley straw is essential, both to improve the soil fertility and to conserve the environment. In order to identify the effects of barley straw mulch rates in rice cultivation, a rice cultivar, 'Gancheogbyeo', was directly seeded on a no-tillage field synchronized with barley harvesting with five barley straw mulch rates, i.e., 0, 2.5, 5.0, 7.5 and 10.0 ton h $a^{-1}$ and agronomic characters of rice and soil nitrogen were determined. The increasing of barley straw mulch rates. Dominant weed species, chestnut, occurred in large amounts in no mulching or lower mulch rates than in higher mulch rates. The content of N $H_4$$_{＋}$-N in soil applied with high barley straw mulch rates was lower during the month after seeding, and then it was higher at heading date, compared with lower mulch rates or no mulch plot. As the barley straw rate increased, maximum tillering stage was delayed, and plant height was reduced. Although the lodging of rice plants was seldom observed in all plots, the breaking strength of the culm was significantly higher in the mulch rate of 10.0 ton h $a^{-1}$ . With an increase of barley straw mulch rate, the effective tillering rate and spikelet number $m^{-2}$ decreased while ripened grain ratio increased. The rice grain yield was slightly decreased with an increase of barley straw mulch rate, although significant differences were not found all barley straw mulch rates. These results suggest that there is no significant yield loss although the total barley straw production, approximately 5.0 ton h $a^{-l}$ in the present study, apply in the paddy for the following rice cultivation by no-tillage direct seeding.ect seeding.

• Asian-Australasian Journal of Animal Sciences
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• v.1 no.4
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• pp.213-218
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• 1988

Forty eight growing bulls of two breed types(red Sahiwal and white Kilari), fed rice straw, were allocated to nine treatment groups: 1. Control straw (CS) 2. Urea upgraded straw (UUS) 3. UUS + 0.25 kg coconut cake (CC) 4. UUS + 0.75 kg CC 5. UUS + 0.25 kg rice bran (RB) 6. UUS + 1.00 kg RB 7. UUS + 0.25 kg RB + 0.25 kg CC 8. UUS + 1.00 kg RB + 0.25 kg CC 9. CS + 1.00 kg RB + 0.25 kg CC Liveweight gain was measured weekly during 15 weeks and tested in three analyses of variance. The results are: Urea upgraded straw produced a liveweight gain $180g.d^{-1}$ higher (P <0.01) than control straw. The groups supplemented with 0.25 kg coconut cake and 1.00 kg rice bran showed an increase of $100g.d^{-1}$ (p < 0.05) over the unsupplemented groups. No interaction between straw upgrading and supplementation was present (P > 0.10). Both rice bran and coconut press cake, supplemented to upgraded straw at a level of 0.25 kg, did not increase liveweight gain (P>0.05), but 1.0 kg rice bran increased gain by $90g.d^{-1}$ (P<0.05). A supplement of 0.75 kg coconut press cake to upgraded straw increased liveweight gain by $160g.d^{-1}$ compared with 0.25 kg or 0.00 kg coconut cake supplement (P<0.05). There were no significant differences between breed types (P>0.10) or interactions between breed and the other two main treatments (upgrading and supplementation). It was concluded. that both urea upgrading and supplementation of rice straw increase animal performance. The effect of urea upgrading was the same for both supplemented and unsupplemented animals. There was no indication of a nonlinear effect of supplements on growth.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.21-28
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• 2013

The objective of the study was to investigate the effect of rice straw mat, rice straw mat with PAM (Polyacrylamide) and gypsum addition on surface runoff and sediment discharge in field. Six experimental plots of $5{\times}22m$ in size and 3 % in slope prepared on gravelly sandy loam soil were treated with control, rice straw mat cover with gypsum and rice straw mat cover with gypsum and PAM. Radish in Spring and Chinese cabbage in autumn growing seasons were cultivated. Non point source (NPS) pollution discharge was monitored and compared among the treatments. Rainfall of the 10 monitored events ranged from 17.0 mm to 93.5 mm. Runoff coefficient of the events was 0.005~0.239 in control plot, 0~0.176 in rice straw plot with gypsum and 0~0.046 in rice straw mat plot with gypsum and PAM. When compared to the control plot, the runoff amount was reduced by 10.4~100 % (Ave. 60.8) in rice straw plot with gypsum and 80.7~100 % (Ave. 96.7 %) in rice straw mat plot with gypsum and PAM. The reduction of NPS pollution load was 54.6 % for BOD5, 71.5 % for SS, 41.6 % for TN and 61.4 % for T-P in rice straw with gypsum plot and 91.9 % for BOD5, 92.0 % for SS, 88.0 % for TN and 88.5 % for T-P in rice straw mat with gypsum and PAM plot. This research revealed that rice straw mat cover with soil amendments on the soil surface could not only increase the crop yield but also reduce the NPS pollution loads substantially.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.191-196
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• 1998

This experiment was conducted to investigate the mulch effect of rice straw and dead water foxtail treated with herbicides on weed germination, seedling establishment, and early growth of rice under the no-till culture condition. The percent seedling establishment of rice straw + dead water foxtail mulch was decreased significantly compared to rice straw mulch and non-mulch. Rice straw mulch and rice straw + dead water foxtail mulch inhibited the early growth of no-till direct seeded rice remarkably. However, they promoted rice growth after active tillering stage. Rice straw mulch and rice straw+dead water foxtail mulch in no-till direct seeding decreased weed occurrence significantly. The control value of barnyardgrass, compared with non-mulch, was 96.5% in the rice straw mulch and 75.6% in the rice straw + dead water foxtail mulch, respectively. The pH and concentration of dissolved oxygen in irrigated water were reduced significantly by both rice straw mulch and rice straw+dead water foxtail mulch during early rice growth stage.