• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1256-1266
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• 2009

Effects of particle size and physical effective fibre (peNDF) of rice straw in diets on chewing activities, feed intake, flow, site and extent of digestion and rumen fermentation in goats were investigated. A 4${\times}$4 Latin square design was employed using 4 mature Liuyang black goats fitted with permanent ruminal, duodenal, and terminal ileal fistulae. During each of the 4 periods, goats were offered 1 of 4 diets that were similar in nutritional content but varied in particle sizes and peNDF through alteration of the theoretical cut length of rice straw (10, 20, 40, and 80 mm, respectively). Dietary peNDF contents were determined using a sieve for particle separation above 8 mm, and were 17.4, 20.9, 22.5 and 25.4%, respectively. Results showed that increasing the particle size and peNDF significantly (p<0.05) increased the time spent on rumination and chewing activities, duodenal starch digestibility and ruminal pH, and decreased ruminal starch digestibility and $NH_{3}$-N concentration. Intake and total tract digestibility of nutrients (i.e. dry matter, organic matter, and starch) and ruminal fermentation were not affected by the dietary particle size and peNDF. Increased particle size and peNDF did not affect ruminal fibre digestibility, but had a great impact on the intestinal and total tract fibre digestibility. The study suggested that rice straw particle size or dietary peNDF was the important influential factor for chewing activity, intestinal fibre and starch digestibility, and ruminal pH, but had minimal impact on feed intake, duodenal and ileal flow, ruminal and total tract digestibility, and ruminal fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1022-1027
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• 2010

Effects of increasing dietary rice straw on chewing activity, ruminal fermentation, and fibrolytic enzyme activity in growing goats were investigated in a $4{\times}4$ Latin Square experiment. The goats were offered four diets with an increasing proportion of rice straw (i.e. 0.05, 0.10, 0.15 and 0.20, respectively, on dry matter basis). Increasing level of rice straw increased ($P_{linear\;effect}$ <0.05) the time spent on eating, ruminating, and chewing. The ruminal pH and acetate: propionate ratio were increased ($P_{linear\;effect}$ <0.05), while the $NH_3$-N concentration was decreased ($P_{linear\;effect}$ <0.01). Increasing level of rice straw in the diet increased ($P_{linear\;effect}{\leq}0.01$) molar proportion of acetate and isovalerate, and decreased ($P_{linear\;effect}$ <0.01) molar proportion of propionate. The CMCase, xylanase and cellobiase activities in the rumen were decreased ($P_{linear\;effect}$ <0.05) with increasing level of dietary rice straw, whereas the avicelase activity was increased ($P_{linear\;effect}$ <0.01). In summary, increased level of rice straw elevated the dietary neutral detergent fibre (NDF) content in the diet and had a great impact on chewing activity and ruminal fermentation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.22-46
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• 2005

Spatial and timely information on crop and filed conditions is one of the most important basics for rational and efficient planning and management in agriculture. Remote sensing, GIS, and modeling are powerful tools for such applications. This paper presents an overview of the state of the art in remote sensing of crop and field conditions with some case studies. It is also shown that a synergistic linkage between process-based models and remote sensing signatures enables us to estimate the multiple crop/ecosystem variables at a dynamic mode. Remotely sensed information can greatly reduce the uncertainty of simulation models by compensating for insufficient availability of data or parameters. This synergistic approach allows the effective use of infrequent and multi-source remote sensing data for estimating important ecosystem variables such as biomass growth and ecosystem $CO_2$ flux. This paper also shows a geo-spatial information system that enables us to integrate, search, extract, process, transform, and calculate any part of the data based on ID#, attributes, and/or by river-basin boundary, administrative boundary, or boundaries of arbitrary shape/size all over Japan. A case study using the system demonstrates that the nitrogen load from fertilizer was closely related to nitrate concentration of groundwater. The combined use of remote sensing, GIS and modeling would have great potential for various agro-ecosystem applications.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.356-364
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• 2009

In 2006 and 2007, there was a big outbreak of the Ussur Brown Katydid, Paratlanticus ussurriensis in the central part of Korea attacking some orchard trees. Until 2000, the katydid had not been regarded as an agricultural pest because they were distributed widely in Korea with low population density and their habitats were confined mainly to hillsides of forested areas. The fact that katydid attacked orchard trees with a higher population density seemed to be related to a change in feeding environment. And the shift of their habitats from oak woodlands to commercial orchards was thought to be related to the nutritional contents of their feed. In an attempt to understand these relationships, we conducted an ecological study of the affected areas. When the katydids changed their habitats in early May of 2008 and 2009, they shifted their host plants from oak trees to peach trees. The habitat shift was closely related to the nitrogen (N) content of the host plant leaves. When katydid moved to the hillside adjacent to orchard farm, N content of oak tree leaves decreased dramatically from 5.3% to 2.2%. At that time N content of peach tree leaves were higher than the 2.2% of oak leaves, showing 3.5~5.0%. This range of N content of peach tree leaves has been consistent until late June. And feed preference analysis carried out in the laboratory showed that katydid prefered peach tree leaves to peach fruit to oak tree leaves.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.423-429
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• 2009

Characteristics of habitat alteration and post-embryonic development of Paratlanticus ussuriensis were investigated in the mountain region of Bitanri, Yeongdong county, Chungcheongbuk-do from 2007 to 2009. Overwintered eggs under the ground in the hillside were hatched from late March to early April. The soil temperature during this season was $7{\sim}14^{\circ}C$. Young nymphs lived mainly at the hillside by eating oak tree leaves but the 3rd or 4th instars switched their habitat to orchards near the hillside in early May, which is the time for sprouting of peach leaves. Old nymphs developed into the adult stage at the orchards in late May and moved back to the hillside in late June. Duration of post-embryonic development from the first instar nymph to adult was 49.2 days after 7 moltings at $25^{\circ}C$. Female adults collected from the field had long ovipositor (26.2 mm) and were slightly longer in the body length, hind femur, tegmen and pronotum than those of males.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.238-242
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• 2009

The effect of earthworm and dung beetle on cattle dung pat decomposition was assessed by combining quantification of earthworm density and with or without dung beetle in pats and measurements of the decomposition rate of these pats. Cattle dung decomposition rate was higher in the pots treated with both earthworm and dung beetle than in the pots with either earthworm or beetle alone. After dung beetle and earthworm activity, the growth of oat in earthworm with dung beetle treatment was similar effect with fertilizer treatment. Dung beetle was responsible for dung decomposition until 78% moisture content in the dung, earthworm was responsible for up to 30% moisture of dung, and two group were not shown any activity for decomposition less 30% moisture content of dung. Therefore dung in the different periods could be broken down by each group. The disappearance and conveyance of dung by earthworm and dung beetle was 72% of the initial dung amount. 10.2% of 72% dung was used making brood balls by dung beetle. Earthworm activity was not an impediment on making brood balls by dung beetles. The interaction of earthworm and dung beetle may have a complementary cooperation rather than competition in the same dung pat. Indeed, development of earthworm accelerate to coexist with dung beetles instead without dung beetles. From this result, maximum benefits of the effective earthworm and dung beetle can be achieved, it is needed to preserve population of earthworm and dung beetles in pasture to sustainable agricultural environment.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2011.11a
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• pp.36-36
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• 2011

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2015.08a
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• pp.59-63
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• 2015

• Korean journal of applied entomology
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• v.48 no.2
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• pp.221-227
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• 2009

Temperature effects on diapause termination of Paratlanticus ussuriensis eggs were studied by measuring embryonic development and hatching rates at various conditions of indoor chilling and overwintering temperatures. Diapausing eggs of P. ussuriensis did not hatch at continued incubation at $25^{\circ}C$ and even after chilling for once at either $5^{\circ}C$ or $10^{\circ}C$ for 30, 45 and 60 days. In addition, double chillings at $5^{\circ}C$ with a 90 days interval at $25^{\circ}C$ did not induce hatching of diapausing eggs. However, double chillings at $10^{\circ}C$ induced hatching at 3.6${\sim}$26.7%. When eggs were incubated at $25^{\circ}C$ after chilling for once at $5^{\circ}C$ for various periods, those weights were not changed but those chilled at $10^{\circ}C$ gradually increased to approximately 1.5 times. When 60-days-old eggs were artificially deposited under the soil at three different mountain sites in September 2007, the hatching rates of the first-overwintered eggs were 11.3, 3.5 and 4.1% and those of the second-overwintered eggs were 25.1, 21.6 and 0.4% at Hoepori, Bitanri and Hwasanri, respectively. Most eggs were hatched from mid-March to mid-April but little bit earlier in southern regions. During the hatching period soil temperatures in three tested locations were around 8 to $12^{\circ}C$. In overall, diapausing eggs of P. ussuriensis were greatly influenced by chilling temperature conditions and those repeated cycles, and may required overwintering for one or two times to hatch for the post-embryonic development.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.21-26
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• 2004

Understanding farmer household and community management of crop diversity is necessary in order to effectively strengthen the local plant genetic resources management system in Vietnam, Assessment and management for distribution of farmer's cultivars of rice, taro and tropical tree species were conducted in four different agro-ecological zones in Vietnam using participatory approaches, focus surveys, diversity fairs, agro-morphological field trials, isozyme analysis to understand why Vietnamese farmers grow diverse types of these crop cultivars, when and where these crops cultivars are grown and how farmers maintain and use them. Results showed significant differences in the extent, distribution and use pattern crop cultivars diversity in contrasting environments and between community farmer households. Seed system is an important role in the access and use of diversity in eco-geographical regions.