• 한국초지조사료학회지
• /
• 제41권3호
• /
• pp.147-154
• /
• 2021

Cutting management has been identified as a critical factor in the alfalfa production systems because it has a significant impact on maximizing yield and maintaining the forage quality. The objective of this experiment was to determine the proper cutting height according to harvesting time for optimizing nutrient yield and forage nutritive quality of alfalfa grown in alpine regions of Korea. Alfalfa was sown at a seeding rate of 30 kg/ha in August 2018 and harvested at four cuttings in 2019 (3 May, 2 July, 11 September, and 13 October). Cutting heights were adjusted at 5, 15, and 25 cm above the soil surface. Alfalfa plant was tallest at the third cutting (109 cm), which was on average 35 cm taller than the first or second cutting. Relative feed value (RFV) remained unaffected by cutting height at the first harvest, but increased consistently in subsequent harvests as cutting height increased. Alfalfa collected at the first and fourth cuttings had the highest RFV (mean 152), which was on average 8 and 67 units higher than the second and third harvests, respectively. At each harvest, in vitro dry matter digestibility was highest in alfalfa cut at a 25-cm height. Dry matter (DM) production at each cutting height was highest in the first cutting, accounting for on average 36-37% of total annual DM production, and lowest in the fourth harvest, accounting for about 11-13% of the total DM yield. The total dry matter production (in four harvests) was 4,218 kg/ha higher when alfalfa was subjected to a cutting height of 5 cm rather than 25 cm. Cutting height had no effect on total crude protein yield, but from the first to fourth cutting, the protein yield followed a decreasing trend. Finally, there were visible declines in forage nutritive quality when alfalfa was cut at a shorter height. However, the magnitude of difference in total forage yield may outweigh the slight decline in forage quality when alfalfa is cut at a lower height. The findings of this study could help the alfalfa growers make better harvest management decisions.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2017년도 9th Asian Crop Science Association conference
• /
• pp.113-113
• /
• 2017

Downy mildew (DM), caused by several species in the Peronosclerospora and Scleropthora genera, is a major maize (Zea mays L.) disease in tropical or subtropical regions. DM is an obligate parasite species in the higher plants and spreads by oospores, wind, and mycelium in seed surface, soil, and living hosts. Owing to its geographical distribution and destructive yield reduction, DM is one of the most severe maize diseases among the maize pathogens. Positional cloning in combination with phenotyping is a general approach to identify disease resistant gene candidates in plants; however, it requires several time-consuming steps including population or fine mapping. Therefore, in the present study, we suggest a new combination strategy to improve the identification of disease resistant gene candidates. Downy mildew (DM) resistant maize was selected from five cultivars using the spreader row technique. Positional cloning and bioinformatics tools identified the DM resistant QTL marker (bnlg1702) and 47 protein coding genes annotations. Eventually, 5 DM resistant gene candidates, including bZIP34, Bak1, and Ppr, were identified by quantitative RT-PCR without fine mapping of the bnlg1702 locus. Specifically, we provided DM resistant gene candidates with our new strategy, including field selection by the spreader row technique without population preparation, the DM resistance region identification by positional cloning using bioinformatics tools, and expression level profiling by quantitative RT-PCR without fine mapping. As whole genome information is available for other crops, we propose applying our novel protocol to other crops or for other diseases with suitable adjustment.

• Geomechanics and Engineering
• /
• 제6권2호
• /
• pp.173-194
• /
• 2014

Laboratory and field data showed that deep mixed (DM) columns accelerated the rate of consolidation of the soft foundations. Most analyses of consolidation of DM column-improved foundations so far have been based on the elastic theory. In reality, the DM columns may yield due to the stress concentration from the soft soil and its limited strength. The influence of column yielding on the degree of consolidation of the soft foundation improved by DM columns has not been well investigated. A three-dimensional mechanically and hydraulically-coupled numerical method was adopted in this study to investigate the degree of consolidation of the DM column foundation considering column yielding. A unit cell model was used, in which the soil was modeled as a linearly elastic material. For a comparison purpose, the DM column was modeled as an elastic or elastic-plastic material. This study examined the aspects of stress transfer, settlement, and degree of consolidation of the foundations without or with the consideration of the yielding of the DM column. A parametric study was conducted to investigate the influence of the column yielding on the stress concentration ratio, settlement, and average degree of consolidation of the DM column foundation. The stress concentration ratio increased and then decreased to reach a constant value with the increase of the column modulus and time. A simplified method was proposed to calculate the maximum stress concentration ratios under undrained and drained conditions considering the column yielding. The simplified method based on a composite foundation concept could conservatively estimate the consolidation settlement. An increase of the column modulus, area replacement ratio, and/or column permeability increased the rate of consolidation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제24권11호
• /
• pp.1560-1568
• /
• 2011

This study was conducted to evaluate the yield, nutrient characteristics, ruminal solubility, degradability and disappearance of spent mushroom (Agaricus bisporus) substrates for ruminants. The annual yield of spent Agaricus bisporus substrates was measured to be about 210,000 tons (M/T) in South Korea. The surface soil-removed spent substrates had nutritional characteristics of high crude ash (375 g/kg) and Ca (32 g/kg), medium protein (134 g/kg CP), and high fiber (384 g/kg NDF on a DM basis). Compared with initial mushroom substrates, spent mushroom substrates had twice higher (p<0.0001) CP content and 22.0% lower (p<0.0001) NDF content on an organic matter basis. Compared with raw rice straw, spent rice straw had much higher (p<0.05) predicted ruminal degradabilities and disappearances of DM and CP and a little lower (p<0.05) predicted degradability and disappearance of NDF. In conclusion, the general feed-nutritional value of spent mushroom (Agaricus bisporus) substrates appeared to improve after cultivation of mushrooms.

• 한국초지조사료학회지
• /
• 제12권4호
• /
• pp.232-238
• /
• 1992

To understand the basic information on the management and utilization of reed canarygrass (Phalaris arundinacea L.), four cultivars of Palaton. Venture, Castor and Frontier (control) were compared for growth characteristics, dry matter (DM) yield and nutritive value, 1990 to 1992. The reed canarygrass was harvested four times annually, at soiling stage. The average plant height at harvest was 60 cm in Frontier, 57 cm in Palaton and Venture, and 52 cm in Castor. Initial heading and heading date in 1990 were ca. 21 May and 29 May, respectively, regardless of cultivar. The highest yield (12.495 kg/ha) in 1990 was observed by Frontier. In 1991. Palaton. Venture and Frontier outyielded Castor significantly, and the yields of all cultivars in 1992 were not significant, ranged from 11,460 kg (Castor) to 12,298 kg/ha (Palaton). On an average for three years, Palaton (10,592 kg), Venturc (10,405 kg) and Frontier (1 1,277 kg/ha) produced more forages than Castor. In Frontier the percentage of DM distribution at first harvest (spring) was highest (32.4%). However, the distributions at third (summer) and fourth (autumn) harvest were high in Palaton and Venture, compared with Frontier. The nutritive value of reed canarygrass was not significantly different among cultivars, and the percentage of weeds was slightly high in Castor reed canarygrass.

• Asian-Australasian Journal of Animal Sciences
• /
• 제7권3호
• /
• pp.335-342
• /
• 1994

This study was undertaken at Gowa, South Sulawesi, Indonesia, as part of a larger forage genetic resource evaluation project. The experimental program consisted of a field experiment where grass and legume species were grown in monocultures and the dry matter yield, rumen bag digestibility (RBDMD) and N content of leaf and stem components were monitored in the wet and dry seasons. Eight species of grass (Brachiaria decwnbens cv. Basilisk. Panicum maximum cv. Riversdale, Urochloa pullulans CPI 41192, Imperata cylindrica from Maiwa, South Sulawesi, Digitaria milanjiana CPI 41193, Cenchrus ciliaris cv. Malopo, Heteropogon contorlus and Setaria sphacelata cv. Splenda) were studied. P. maximum was the highest yielding grass in the wet season and B. decumbens in the dry season. The highest RBDMD in the whole plants were U. pulluians, P. maximum, S. sphacelata and D. milanjiana after 2 weeks regrowth in cycle I and S. sphacelata, B. decumbens, D. milanjiana and C. ciliaris in cycle 2. When total digestible DM was calculated for the whole of cycle I, P. maximum, B. decumbens and S. sphacelata were superior, but B. decumbens produced over twice as much as the other species in the dry season (cycle 2). The leaf N concentration of all grasses exceeded 1.0% (6.25% crude protein) in the regrowth in cycle I but did not exceed 0.5% in the dry season regrowth (cycle 2).

• 한국초지조사료학회지
• /
• 제18권3호
• /
• pp.251-258
• /
• 1998

To find out the effect of NPK-fertilization level and utilization method of pasture plants on the productivity of dry matter and nutrient of forages in hilly pasture, this experiment was arranged as a split block design with six treatments of 2 mainplots(N-$P_2O_5$-$K_2O$=210-150-180(wntrol), 280-200-240Kg/ha) and 3 subplots (cutting, grazing cutting+grazing alternative), and conducted at hilly land in Yeoju, Kyonggi Province 6om February, 1992 to October, 1993. In the treatment of grazing the early growth and cover degree of pasture plants wintered were more favorable. With increased NPK-application for two years, the average dry matter(DM) yield of 9,862kglha was incerased by 18% than that of the control, and the average DM yield of the cutting treatment of 10,434kaa was higher than that of others. In all treatments for two years, the average DM yield was composed of 94.0~95.1% grasses, 1.8~2.0% legumes and 2.8~4.2% weeds. The crude protein and energy productivity of forages in the treatment with increased NPK-fertilizer application increased by 20~23% than those of control, and those of cutting treatment were greatly increased than those of the grazing treatment. The average mineral content of forages in all treatments tended to be similar, Ca and Mg content and Ca/P ratio were slightly lower, and K content and K/(Ca+Mg) equivalent ratio of forages tended to be higher than the most desirable value of forages.

• 한국초지조사료학회지
• /
• 제41권2호
• /
• pp.84-95
• /
• 2021

The purpose of this study was to assess the forage productivity and nutritive value of kenaf at different fertilizer application amounts and various stages of maturity. The experiment was conducted from May to September 2020, the amount of 80 kg of kenaf seed/ha was supplied with different types and amounts of nitrogen fertilizer and the plants were harvested at 10-day intervals from different harvesting dates (24^th August and 3^rd, 13^th, 23^rd September). According to the different fertilizer types and application amounts, the highest kenaf height was recorded in the inorganic fertilizer amounts of 200 and 250 kg N/ha and the fresh and DM yield were significantly improved in the inorganic nitrogen amount of 250 kg N/ha. The highest CP and TDN content in the leaf was achieved in the inorganic fertilizer amounts of 150 and 200 kg N/ha, respectively; and the highest TDN content in the stem was also found in the inorganic fertilizer amount of 200 kg N/ha. According to the different harvesting dates, the highest DM ratio was found in the harvesting date of 13th September, the leaf ratio increased with advanced maturity, whereas the stem ratio decreased significantly and the highest DM yield of kenaf was recorded in the harvesting dates of 13^th and 23^rd September. Besides, the highest CP, CF, CA, ADF, NDF and TDN content in the leaf as influenced by different harvesting dates was 15.4, 31.8, 10.2, 22.1, 34.7 and 76.5%, respectively, and the CP, CA, ADF and TDN in stem decreased significantly with advanced maturity of kenaf. In conclusion, the optimal fertilizer amounts and the appropriate harvesting dates for a high forage yield and high-quality kenaf as livestock feed were the inorganic fertilizer application amounts of 200-250 kg N/ha and from 13^th and 23^rd September, respectively.

• 한국초지조사료학회지
• /
• 제11권3호
• /
• pp.182-188
• /
• 1991

With a purpose of finding out the effects of cattle slurry applicatioin on the dry matter yield, yield component, and botanical composition in the mixed sward, a field experiment was conducted with two times and five levels of cattle slurry application. The experimental field was laid.out in a split-plot design with three replications, and lasted from September. 1986 to October, 1990 at the Livestock Experiment Station in Suweon, The results obtained are summarized as follows: 1. At each harvest time, the plant growth of the plots with cattle slurry application was slightly worse when compared to dressing of mineral fertilizer. 2. Average dry matter yield for 4 years was not significantly different between the slurry application times, just after cutting, and 15 days after cutting, The DM yield in the plot with cattle slurry 30 m!/ha and mineral fertilizer(9,095 kg/ha) and with cattle slurry 60 m1/ha and mineral fertilizer(8, 987 kg/ha) were decreased by 8% and 10% than that of the plot with mineral fertilizer application(9,937 kg/ha), respectively. 3. The DM yield component of the plots with cattle slurry application just after cutting was much better when compared to manuring 15 days after cutting. And it was much better in the plot with cattle slurry 60 m"/ha and mineral fertilizer which was composed of 73.8% grasses(6.636 kg/ha). 24.6% legumes (2,207 kdha) and 1.6% weeds(144 kdha). 4. In general, the botanical composition was relatively good in the plots with slurry application just after cutting. Grassland vegetation of the plots with cattle slurry 60 m"/ha and mineral fertilizer was changed into much better botanical composition with 66.8% grasses, 30.2% legumes and 3. 1% weeds at the end of the experiment.xperiment.

• Asian-Australasian Journal of Animal Sciences
• /
• 제7권3호
• /
• pp.325-333
• /
• 1994

This study was undertaken at Gowa, South Sulawesi, Indonesia as part of a larger forage genetic resource evaluation project. The experimental program consisted of a field experiment where grasses and legume species were grown in monocultures and the yield, N content and rumen bag digestibility using goats were measured. The field experiment was conducted from December 1985 to October 1986. Eight species of legumes (Desmodium heterophyllum cv. John-stone, Desmodium triflorum from Gowa, South Sulawesi, Arachis sp. from Maiwa, South Sulawesi, Clitoria ternalea CPI 50973, Macroptilium atropurpureum ev. Siratro, Neonotonia wightii cv. Tinaroo, Centrosema pubescens CPI 58575, Centrosema plumeri CPI 58568) were grown as monocultures. After establishment all plants were cut to a uniform height of 5 cm, and subsequent cuts were made on regrowth after 14, 28, 42, and 56 days (cycle 1). Cycle 2 commenced towards the end of the wet season and continued for 157 days into the dry season. The highest yielding legumes were C. ternatea in the wet season and Arachis sp. in the dry season. The mean rumen bag dry matter digestibility (RBDMD) of legumes of 67.6% for leaf material (averaged over all cycles and ages) was 7.6% higher than for stem material. The RBDMD of Arachis was significantly higher than all other species. The RBDMD of all legumes declined with age. Calculation of yield of digestible DM (yield $\times$ RBDMD) showed that Arachis sp. was the best legume. The combination of plant "quality" with yield measures is a valuable adjunct to routine agronomic survey procedures in plant evaluation programs. Arachis sp. appears to offer considerable promise and should be more widely evaluated.