• Journal of Animal Science and Technology
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• 제63권2호
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• pp.339-353
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• 2021

This study aimed to assess the causality of different climate variables on the production of whole crop maize (Zea mays L.; WCM) in the central inland region of the Korea. Furthermore, the effect of these climate variables was also determined by looking at direct and indirect pathways during the stages before and after silking. The WCM metadata (n = 640) were collected from the Rural Development Administration's reports of new variety adaptability from 1985-2011 (27 years). The climate data was collected based on year and location from the Korean Meteorology Administration's weather information system. Causality, in this study, was defined by various cause-and-effect relationships between climatic factors, such as temperature, rainfall amount, sunshine duration, wind speed and relative humidity in the seeding to silking stage and the silking to harvesting stage. All climate variables except wind speed were different before and after the silking stage, which indicates the silking occurred during the period when the Korean season changed from spring to summer. Therefore, the structure of causality was constructed by taking account of the climate variables that were divided by the silking stage. In particular, the indirect effect of rainfall through the appropriate temperature range was different before and after the silking stage. The damage caused by heat-humidity was having effect before the silking stage while the damage caused by night-heat was not affecting WCM production. There was a large variation in soil surface temperature and rainfall before and after the silking stage. Over 350 mm of rainfall affected dry matter yield (DMY) when soil surface temperatures were less than 22℃ before the silking stage. Over 900 mm of rainfall also affected DMY when soil surface temperatures were over 27℃ after the silking stage. For the longitudinal effects of soil surface temperature and rainfall amount, less than 22℃ soil surface temperature and over 300 mm of rainfall before the silking stage affected yield through over 26℃ soil surface temperature and less than 900 mm rainfall after the silking stage, respectively.

• 한국초지조사료학회지
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• 제17권3호
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• pp.265-276
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• 1997

This study was investigated the herbage productivity and nutrient contents of corn (Suweon 19 and Kwanganok) and sweet sorghum (Ramiki sorgo and Silage sorgo) at the stage of maturity (10-DBS, silking, milky and dough stages) to identify the utility value of sweet sorghum as a substituting crop for corn. The silage materials (dough stage) were chopped and were storaged for 90 days in polyethlene bag with O.lmm thickness. Chemical composition, nitrogen content and in vitm dry matter digestibility were evaluated. Also, daily intake and palatability were checked in the feeding trial with four male sheep in average weight about 57kg. Both fresh and dry matter yield of corn and sweet sorghum were increased as the maturity processed (P< 0.05), and sweet sorghum showed higher total yield potential than corn. Crude protein content of the cultivars was decreased as the maturity was processed (P< 0.05). Neutral detergent fiber (NDF) content of the cultivars, in general, showed highest at silking stage, followed by 10 days before silking (10-DBS), and milky and dough stages (Pi0.05) in order. Acid detergent fiber (ADF) content was increased as the maturity processed, and it showed the highest value at milk stage. However, the contents of ADF in sorghum plant was decreased during the late maturity. Crude protein content of the silage was not significantly different among cultivars used, while NDF content was highest in Ramiki sorgo, followed by Silage sorgo, Kwanganok and Suweon 19. In v i m DM digestibility of the silage was highest in Kwanganok, followed by Suweon 19, Silage sorgo and Ramiki sorgo. Total N content of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok. DM intake of the silage was highest in Ramiki sorgo, followed by Suweon 19, Silage sorgo and Kwanganok and it was closely related to the palatability value.

• 한국작물학회지
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• 제53권1호
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• pp.93-101
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• 2008

The effects of $CO_2$ enrichment on growth of maize (Zea mays L.) were examined. Parameters analyzed include growth characteristics, yields, photosynthetic rates, evaporation rates and photosynthesis-related characteristics under elevated $CO_2$. The plants were grown in growth chambers with a 12-h photoperiod and a day/night temperature of $28/21^{\circ}C$ at the seedling stage and $30/23^{\circ}C$ from the silking stage. The plants were exposed to two elevated $CO_2$ of 500, 700ppm and ambient levels (350 ppm). Chalok 1 and GCB 70 germinated three days after seeding, and germination rates were faster in the elevated $CO_2$ than the control. Germination rates displayed significant differences among the $CO_2$ treatments. At the seedling stage, leaf area, top dry weight, and photosynthetic rates, and plant height indicated positive relationship with elevated $CO_2$ concentrations. At the $5{\sim}6$ leaf stage, $CO_2$ concentration also indicated positive relationship with plant height, leaf area, top dry weight, and photosynthetic rates. At the silking stage, increased plant height of Chalok 1 was noted in the $CO_2$ treatments compared to the control. No significant differences were noted for GCB 70, in which leaf area decreased but photosynthetic rates increased progressively with $CO_2$ concentration. Stomatal aperture was a little bigger in the elevated $CO_2$ than the control. $CO_2$ concentration was negatively related to stomatal conductance and transpiration rates, resulting in high water use efficiency.

• 농업과학연구
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• 제39권1호
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• pp.29-34
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• 2012

This study was carried out to identify the characteristics of 37 corn hybrids, which composed with 18 yellow colored kernel, 9 purple colored kernel, 8 white colored kernel. Days to silking of three colored waxy corn hybrids ranged from 61 to 73 days after sowing as midium-late ecotype. Ear length of hybrids ranged from 10.3 to 22.7 cm, and among them a total 22 waxy corn hybrids including CNU038 showed over 20 cm in ear length. The fresh weight per ear ranged from 58 to 289 g as the 32.9% of large coefficient of variance. In there results, we found yellow colored waxy corn hybrids showed relatively longer in ear length and heavier in fresh weight per ear compare to other colored waxy corn hybrids. In correlation relationships, plant height, ear height, stem diameter, ear length and ear weight showed positive correlation between themselves, while tip filling ratio did negative correlation with silking stage, plant height, ear length, ear weight and kernel thickness. Also, 100 kernel weight did positive correlation between traits related to ear and kernel.

• 한국초지조사료학회지
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• 제11권2호
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• pp.137-142
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• 1991

For the constitution of forage cropping system including the double-cropping of corn, attention has been directed towards the early and short maturing varieties of corn such as Comet 80, Comet 85 and Linda as a component forage crop of forage cropping system. Four corn varieties, Comet 80, Comet 85, Linda and Suwon 19 were planted delayedly by each of 45, 55 and 65 days from the recommended sowing date of suwon 19. Under these condition, growth characteristics and late-sowing adaptability of 4 corn varieties were investigated, and the results are summarized as follows; 1. The variety of suwon 19 did not reach the stage of silking in the occasion of late sowing by 50 days from the optimum sowing time for mono cropping of suwon 19. However early varieties such as Comet 80, Comet 85 and Linda silked under the condition of 65 days-delayed sowing from the recommended sowing time of Suwon 19 for mono-cropping. 2. Early varieties of Comet 80, Comet 85 and Linda were so grown by approximately 92% in plant height, 66% in ear height, 88% in stem diameter and 81% in leaf number respectively compared to Suwon 19 at each of three delayed sowing time that exhibited the dwarfish appearance of canopy. 3. Days from sowing to silking decreased as the sowing time was delayed and the average days from sowing to silking in the sowing treatments of 55 days-delayed of Suwon 19, Comet 80, Comet 85 and Linda were 61, 46, 47 and 51 days, respectively. 4. The size of variations of plant height and ear height influenced by delayed-sowing time was comparatively larger in the varieties of Suwon 19 and Linda than in those of Comet 80 and Comet 85. 5. As sowing time was delayed from the optimum sowing time of Suwon 19 for mono-cropping, ear content decreased from 0% of Suwon 19 at 55 day-delayed sowing treatment to 3540% of Comet 80 and Comet 85 at 65 days-delayed sowing treatment.

• Journal of Animal Science and Technology
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• 제44권2호
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• pp.251-260
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• 2002

옥수수를 호밀과 조합한 연간 2모작의 작부체계하에서는 옥수수의 파종시기가 5월 중순이후로 지연된다. 따라서 본 시험은 전작물이 호밀 때문에 옥수수의 파종시기가 5월 21일로 지연되었을 때 건물수량과 품질을 극대화 할 수 있는 적정 수확시기를 결정하기 위하여 수행하였다. 사일리지용 옥수수는 서울대학교 부속목장에서 5월 21일에 파종하고, 수확은 8개의 다른 숙기에서 수확하였다. 수확시 숙기는 수포형성기 (출사후 16일), 유숙기 (20일), 유숙후기 (26일), 연호숙기 (28일), 황숙초기 (33일), 황숙중기 (38일), 황숙후기 (44일), 및 생리적성숙기 (53일)로 하였다. 황숙초기에서 황숙후기의 전 식물체 건물률은 29.0～38.5%로 사일리지 생산에 가장 적합하였다. 건물 및 가소화영양소총량 (TDN) 수량이 최대인 시기는 황숙중기로 각각 14,831 및 10,675 kg/ha 이었다. 숙기가 진행됨에 따라 전식물체의 ADF 함량은 35.4%에서 22.1%로 감소하였고 NDF 함량 또한 63.8%에서 46.0%로 감소하였다 (P$<$0.05). ADF 및 NDF 함량의 감소는 옥수수의 부위별 함량 변화와 관련이 높다. 즉 숙기가 진행됨에 따라 옥수수의 부위중 암이삭은 증가하고 경엽은 상대적으로 감소하였다. ADF 함량에 의해 계산된 비유정미에너지 (NEL) 및 TDN은 경엽의 경우에는 황숙초기까지는 감소하고 그 이후에는 증가하였으나, 종실과 전식물체의 NEL 및 TDN은 숙기가 진행됨에 따라 유의적으로 증가하였다. In vitro 건물소화율은 숙기가 진행됨에 따라 경엽은 61.1%에서 49.7%로 감소한 반면 전식물체는 58.3%에서 65.7%로 증가하였다 (P$<$0.05). 이상의 결과로 미루어 볼 때 만기파종시 최대건물수량과 품질을 가진 사일리지용 옥수수를 생산하기 위해서는 황숙중기 (1/2 milkline) 에서 황숙후기 (2/3 milkline) 사이에 수확하여야 한다. 그리고 이때 출사후일수는 38일에서 44일 사이였다.

• 한국토양비료학회지
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• 제38권4호
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• pp.211-217
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• 2005

미사식양토에서 질소로 $240kg\;ha^{-1}$에 상당하는 생헤어리뱃치와 화학비료 초안(질산암모늄)을 옥수수 파종 1주일 전에 토양에 혼입하고 옥수수를 재배하면서 토양 무기태질소, 미생물태질소, 옥수수 지상부의 질소 집적량을 1997년부터 2년간 조사하였다. 헤어리벳치의 초기분해 시 초안 유래의 질산태질소의 60-70%에 달하는 질소량이 헤어리뱃치로부터 무기화되어 토층 0-15 cm에 집적되었다. 또한 토양미생물태 질소도 헤어리뱃치구가 초안구보다 $10-20mg\;kg^{-1}$ 증가하였으며 약간의 헤어리뱃치 유래 토양무기태 질소는 천천히 무기화되어 출사기 이후까지 옥수수에 공급되는 것으로 보였다. 출사기에서의 옥수수의 전체 질소 집적량은 2년간 모두 두 질소원 간에 차이가 없었다. 옥수수 수확기의 질소 집적량은 1997년도에는 헤어리뱃치 녹비구가 초안구보다 8% 적었지만 1998년도는 오히려 19% 증가하였다. 질소원으로서 $240kg\;N\;ha^{-1}$에 달하는 헤어리벳치녹비의 시용은 완효적인 질소무기화 효과를 나타내었으며 같은 량의 질소 화학비료를 대체할 수 있는 옥수수 생육촉진 효과를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.224-232
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• 2019

Objective: Apart from various climatic differences, corn harvest stage and varieties are two major factors that can influence the yield and quality of corn silage in the tropics. A study was conducted to determine the optimum harvest stage of four corn varieties for silage production in Malaysia. Methods: Corn was harvested at four growth stages; silking, milk, dough, and dent stages from four varieties; Sweet Corn hybrid 926, Suwan, breeding test line (BTL) 1 and BTL 2. Using a split plot design, the treatments were then analysed based on the plant growth performance, yield, nutritive and feeding values followed by a financial feasibility study for potential commercialization. Results: Significant differences and interactions were detected across the parameters suggesting varying responses among the varieties towards the harvest stages. Sweet Corn was best harvested early in the dough stage due to high dry matter (DM) yield, digestible nutrient, and energy content with low fibre portion. Suwan was recommended to be harvested at the dent stage when it gave the highest DM yield with optimum digestible nutrient and energy content with low acid detergent fibre. BTL 1 and BTL 2 varieties can either be harvested at dough or dent stages as the crude protein, crude fibre, DM yield, DM content, digestible nutrient and energy were not significantly different at either stage. Further financial analysis showed that only Sweet Corn production was not financially feasible while Suwan had the best financial appraisal values among the grain varieties. Conclusion: In conclusion, only the grain varieties tested had the potential for silage making according to their optimum harvest stage but Suwan is highly recommended for commercialization as it was the most profitable.

• 한국초지조사료학회지
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• 제17권3호
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• pp.293-304
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• 1997

A field experiment was conducted at the forage experimental plots, Seoul National University, Suweon h m 1995 to 1996 to determine the effect of legume residues as a N source and N fertilizer on corn (Zea mays L.) silage yield, N uptake, and availability of inorganic N in the soil. Corn was grown following (i) red clover (Trifolium pratense L.), (ii) crimson clover (Trifolium incarnatum L.), (iii) alfalfa (Medicago sativa L.) and (iv) winter fallow. The plots were split into two rates of fertilizer N (0 and 90kg Nlha) in a split-plot experimental plan. Compared with fallow treatment, legumes depleted soil water in the surface 15cm at corn planting by 17 to 26%. As a result, corn emergence was markedly delayed with legume residues by 8 to 11 days. Corn silage DM yield was significantly reduced in the presence of legume residues by 2.0 to 3.4 and 1.5 to 2.5 tonlha compared with winter fallow treatment at 0 and 90kg fertilizer Nlha, respectively, but no significant difference in the corn DM yield was found between legume residue treatments. There was an overall tendency for increased corn yields with 90kg fertilizer Nlha compared to Okg fertilizer Nlha, although not all yield increases were significantly greater. The corn yield response to applied N suggests that a source of N from legume residues was not sufficient for a succeeding corn crop. There was significantly more N (P

• 한국작물학회지
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• 제46권4호
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• pp.266-271
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• 2001

Soybean can produce high-N residue due to N-fixation, so soybean rotation may increase yield of subsequent corn and reduce N fertilizer on the corn fairly. To find out the contribution of nitrogen to subsequent corn following soybean cultivation, soil nitrate, corn yield, and nitrogen uptake were measured for three continuous corn cropping years after soybean rotation. Three N rates of 0, 80, and 160 kg/ha were applied to three continuous corn following soybean cropping. At 6-leaf stage, soil nitrate amount at the soil depth of 0-30cm ranged from 60 to 80 kgN/ha higher in the first corn cropping year than that in the second and third corn cropping years. Judging from corn N status such as SPAD value, N concentration of ear-leaf and stover at silking stage, N contribution of previous soybean to corn in the first corn year was N fertilizer of approximately 80 kg N/ha. Stover N uptake at silking stage increased from 47 to 52 kg N/ha at the 0, and 80 kg N/ha of N rates in the first corn cropping year compared with those in the second and third corn cropping years. Corn grain yield at the 0 kg N/ha of N rate was 6-7 ton/ha higher in the first corn cropping year than that in the second and third corn cropping years, respectively. When compared the first corn year following soybean cropping with the second and third corn cropping years, N uptake of grain and stover at harvest with low N rates such as 0 and 80 kg N/ha increased from 45 to 67kg N/ha, from 35 to 60 kg N/ha, respectively. N uptake of whole plant by soybean rotation increased from 93 to 118 kg N/ha in the first year compared with that in the second and third corn cropping years. However, the N contribution by soybean cropping was small in the second and third continuous corn cropping years. Therefore, it was concluded that the nitrogen fertilizer of 80-100 kg N/ha in the first corn cropping year could be saved by soybean rotation and annual alternative corn-soybean rotation could be the best rotation system.