• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.470-476
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• 2014

The purpose of this study was to investigate the effects of sowing time on ecological responses, growth, and yields of cowpeas grown in plastic greenhouses in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (Latitude $35^{\circ}$ 04' N, Longitude $126^{\circ}$ 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed between mid-March and mid-August at intervals of one month. The days from sowing to emergence was significantly higher for the mid-March sowing (12 days) but no significant differences were observed among the other sowing dates (3 to 4 days). The days from sowing to first flowering were shorter for sowing dates between mid-March and mid-July because sowing time was delayed and then were lengthened again at mid-August sowing; the days were longest at mid-March sowing (around 75 days) and were shortest at mid-July sowing (30 days). The days from first flowering to harvesting were short for the sowing dates between mid-March and mid-May (24 to 28 days) but were relatively long for subsequent sowing dates (35 to 38 days). Stem and peduncle lengths were relatively long for the mid-April and mid-August sowing dates. Main-stem node number was highest for the mid-June sowing. Branch number per plant was highest for the mid-March sowing. The mid-March sowing displayed the highest number of pods per plant as well as the heaviest seed weight. Yield per 10 ares was highest for the mid-March sown Jeonnam1 and the Jeonnam2 strains (340 and 367 kg respectively), and then tended to decrease due to subsequent delays in sowing.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.1
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• pp.17-22
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• 1999

Experiment was carried out to determine the agronomic characteristics, forage yield of silage corn(Zea mays L.) soil chemical characterictics and $NO_3-N$ level in infiltration water by different application rates of daily liquid manures. Four treatment consisting of chemical fetilizer, $200kg\;N\;ha^{-1}$, daily liquid manure $200kg\;N\;ha^{-1}$, $300kg\;N\;ha^{-1}$ and $400kg\;N\;ha^{-1}$ were arranged in a randonmized complete block design with three replicates. The results obtained at National Livestock Research Institute, RDA., in Suwon from 1996 to 1997 are summarized as follows; In plant height and crude protein content, it were appeared to highest by 264cm, 6.8% at the cattle slurry 150% plot(T3), respectively. but Dry matter yield(14.5MT/ha) and TDN(9.5MT/ha) production of chemical fertilizer plot(T1) were highest. Among daily liquid manure amount, dry matter yield(14.0MT/ha) and TDN yield(9.1MT/ha) of daily liquid manure 100% plot(T2) were resulted to 96% and 97% of chemical fertilizer plot(T1). End year's soil organic matter and phosphate content were appeared to high than those of beginning year in daily liquid manure plots, but it was not in proportioned to increase according to slurry amount. $NO_3-N$ level in infiltration water lower than 60cm of all plots were lowed than a permitted limit of cattle drinkable. As a result, it was appeared that the optimum application amount of dairy liquid manure was 200kg/ha by manure-N.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.3
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• pp.155-160
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• 2007

This experiment was conducted to compare the agronomic characteristics and productivity in induced vetch cultivars at paddy field of Cheonan (National Institute of Animal Science) and Naju (Jeollanam-Do Agricultural Research and Extension) from 2004 to 2006. The vetch cultivars used in this study were 6 varieties ('VV4712', 'Welta', 'Penn-02', 'Ostsaat', 'Oregon com.', 'Sander 2'). At the Naju region, the most fast flowering date variety was Chinese milk vetch, Sander 2 was very late as 20th May. The average dry matter (DM) content was 21.7%. Vetch cultivars were severely different. 'Oregon com.' showed the highest DM yield by 5,406 kg/ha but the DM yield of 'Ostsaat' was low by 4,852 kg/ha. At the Cheonan region, the most fast flowering date variety was Korean milk vetch, Sander 2 was very late as 25th May. The average dry matter (DM) content was 16.9%. Vetch cultivars were severely different. 'Welta' and 'Ostsaat' showed the highest DM yield by 2,173 kg/ha and 1,883 kg/ha respectively, but the DM yield of 'VV4712' was low by 1,079 kg/ha. Crude protein (CP) content of vetch was 11.5%. 'Sander 2' showed the highest CP content by 14.4% and Chinese milk vetch showed the highest content by 19.3%. Average acid detergent fiber (ADF), neutral detergent fiber (NDF) and total digestible nutrient (TDN) content were 26.8%, 42.2% and 67.5%, respectively. The results of this experiments indicated that the productivity of vetch cultivar varied from winter hardness, therefore we will consider the winter hardness as main factor when induce vetch cultivars. According to the results obtained from this study, it is suggested that 'Oregon com.' at the Naju region and 'Welta' and 'Ostsaat' at the Cheonan region would be recommendable for fall sown 'vetch' for dry matter production.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.3
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• pp.183-188
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• 2007

This study was conducted to determine the effects of seeding date on agronomic characteristics, productivity and feed value of Italian ryegrass, barley and rye during cropping after rice in Suwon, middle region of Korea, during 2004 and 2005. In general, early seeding (26 September) showed longer plant length and branch numbers per square meter than late sowing (11 October). Italian ryegrass had more early seeding effect than barley and rye. The yield of each plant was affected by sowing date in all experiments: the earlier seeding had higher yields than late seeding. In case of Italian ryegrass and barley as late-heading varieties showed more early seeding effect than rye. On the other hand, feed value tended to respond differently to yields. The feed value of each plant were based on liquid swine manure (12%) > composted cattle manure (7%) > composted swine manure (2%). The present results highlight the earlier planting obtained higher yield compared to those planted conventionally.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.343-352
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• 2012

This experiment was carried out to report some data such as survival rate, tetraploid production efficiency, and agronomic characteristics of offspring from the induced tetraploid by the colchicine treatment in rye. The colchicine was soaked with 0.05%, 12 hours in dark condition and at two growth stages (green seed and 2nd leaf stage) in diploid ryes. Flow cytometry (FC) was proved to be efficient and rapid tool for screening ploidy levels in rye, showing around 40 to 60 in DNA amount (DAP1) corresponding to diploid and 80 to 110 tetraploid. There were 18.5% of survival rate at green seed treatment and 78% at 2nd leaf stage in average of two rye cultivars, Gogu and Jogreen, but in reverse 50.9% and 1.1% in the ratio of tetraploid to total tillers among the plants survived, respectively, resulting in 9.42% of tetraploid production rate in green seed treatment and 0.86% at 2nd leaf stage, respectively. In green seed treatment, there were 33% of survival rate in Gogu, 4% in Jogreen in 1st year, but 56% in Gogu, 21% in Jogreen and 49% in Charmgreen, respectively. The rate of tetraploid to total spikes among survived was 53.7% in Gogu, 32.4% in Jogreen, and 50.9% in average in 1st year, and 64.1% in Gogu, 51.5% in Jogreen, 60% in Charmgreen, and 60.5% in average in 2nd year. In green seed treatment, tetraploid production rate (survival rate ${\times}$ tetraploid ratio ${\times}$ 100) was 17.7% in Gogu and 1.3% in Jogreen and 9.42% in average in 1st year, and 35.9% in Gogu, 10.8% in Jogreen, 29.4% in Charmgreen, and 25.4% in average of three diploid rye cultivars. By the colchicine treatment with 0.05% for 12 hours in Gogu and Jogreen, 35 tetraploid plants were obtained and they produced 2,673 seeds with 148 spikes. There were 3.3-4.4 in the number of spikes per plant, 15.6-18.3 in grain number per spike, and 37.6 g in Gogu and 46.8 g in Jogreen in the 1,000-grain weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.161-171
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• 2020

Direct seeding is one of the rice seedling establishment methods that is increasingly being practiced by farmers to save labor and reduce costs. However, this method often causes poor germination under flooding conditions after sowing. In this study, we developed japonica elite lines with quantitative trait loci (QTL) associated with anaerobic germination (AG) tolerance to overcome poor germination and seedling establishment in wet direct seeding. The QTL introgression lines were developed from a cross between weedy photoblastic rice as the AG donor and the Nampyeong variety via phenotypic and genotypic selection. Compared to Nampyeong, the survival rates of the selected lines were improved by approximately 50% and 240% under field and greenhouse conditions, respectively. To improve selection efficiency by marker assisted selection, the QTL markers associated with AG tolerance were converted to cleaved amplified polymorphic sequence markers designed based on next-generation sequence analysis. These lines retained similar agronomic traits and yield potential to the parent, Nampyeong. Among these lines, we selected the most promising line, which exhibited high survival rate and good agricultural traits under flooding conditions and named the line as Jeonju643. This line will contribute to breeding programs aiming to develop rice cultivars adapted to wet direct seeding. This study demonstrates the successful application of marker-assisted selection to targeted introgression of anaerobic genes into a premium quality japonica rice variety.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.109-114
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• 1999

This study was carried out to obtain some information on the sustainability of paddy rice through the long-term variation of nitrogen use efficiency. The experiment was conducted during 30-year with the same amount of N, P, K and compost at Milyang, southern part of Korea. The results were as follows. Grain yield was increased significantly in the plots of compost incorporation only. However, yield productivity was decreased slightly in the plots with nil and unbalanced fertilization. The effects of rice straw compost on grain yield was not clear at the early crop years but was shown slightly at the late period of the experimental. The grain yield in the plots of compost incorporation at 30th crop year was come to about 80% of NPK plots. The amount of nitrogen uptaken by rice plant was the highest as $167kg\;ha^{-1}$ in NPK plus compost incorporation. Recovery efficiency)($RE_N$) was higher as 0.48~0.74 in compost incorporation plots than in other plots of balanced and unbalanced application. Average agronomic efficiency($AE-N$) and partial factor productivity from N fertilizer applied($PFP_N$) during 30 crop years in NPK plots was 12.8 kg/kg N and 37.7 kg/kg N, respectively, and difference of $AE-N$ and $PFP_N$ shown as indigenous soil nitrogen supply(INS) was higher as 28.4 kg/kg N in NPK + compost plot than NPK plot and was widened at the late period of experiment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.105-111
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• 2015

"Seedgreen" (Secale cereal L.), a new rye cultivar was developed by National Institute of Crop Science (NICS), RDA in 2013. It was developed from an open pollination from within 10 rye varieties or lines including "Chochun" in 1995. The line "SR95POP-S1-140-9-1-3-7-5-3" was selected for its excellent agronomic appearance, and was placed in yield trials for three years from 2008 to 2010. The new cultivar was designated "Homil50" and was placed in regional yield trials at the five locations around Korea from 2011 to 2013, during which time the name "Seedgreen" was given. This cultivar is an erect plant type and of a long size, with a dark-green leaf color, a yellowish-white colored, medium-diameter culm, and a brown-colored, medium-size grain. The heading and maturation dates of Seedgreen were April 22 and June 16, which were 3 days and 2 days earlier than that of "Gogu", respectively. Seedgreen also showed better winter hardiness and a greater resistance to lodging and wet injury compared to those of the check cultivar. Over three years, the average dry matter yield of Seedgreen was 8.3 ton $ha^{-1}$ (fresh yield = 39.8 ton $ha^{-1}$), which was harvested in late April and was lower than that of the check cultivar Gogu. The seed productivity of Seedgreen was approximately 4 ton $ha^{-1}$, which was 16 % more than that of the check. Seedgreen was higher to than Gogu in term of protein content (10.5% and 9.7%, respectively), total digestible nutrients (TDN) (58.3% and 57%, respectively), and TDN yield $ha^{-1}$ (4.81 ton and 4.77 ton, respectively). This cultivar is recommended as a fall sowing crop in areas where the average daily minimum-mean temperatures are higher than $-12^{\circ}C$ in January, and as a winter crop for whole-crop forage before the planting of rice or green manure around Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.301-306
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• 2008

This experiment was conducted to compare the agronomic characteristics, productivity of silage com and barley cropping, forage sorghum and barley cropping in accordance with Drainage Culvert Spacing at poorly drained paddy field in National Institute of Animal Science, at Seonghwan in Korea, March 2006 to May 2007. The emergency and flowering date were no different among treatments. Emergency rate and flowering date were 90% and July 26 in silage com, 91% and July 21 in forage sorghum, 92% and April 27 in barley, respectively. Dry matter yield was high in line with 3 m drainage culvert spacing (24,389 kg/ha) > 5 m (23,543 kg/ha) > 7 m (21,527 kg/ha) > 0 m (14,132 kg/ha). In cropping systems, dry matter yield of forage sorghum and barley (22,111 kg/ha) was higher than silage com and barley (19,684 kg/ha). Crude protein and TDN yield were high in line with 3 m (2,365 and 15,394 kg/ha) > 5 m (2,255 and 14,513 kg/ha) > 7 m (1,884 and 13,747 kg/ha) > 0 m (995 and 8,682 kg/ha). In cropping systems, crude protein and TDN (total digestible nutrients) yield of forage sorghum and barley cropping system (2,165 and 13,582 kg/ha) was higher than silage com and barley cropping system (1,576 kg/ha and 12,482 kg/ha), respectively. Consequently proper drainage culvert Spacing at poorly drained paddy field was 5 m with forage sorghum and barley cropping system.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.157-163
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• 2005

The increasing of greenhouse gases may change agricultural environment. The agronomic productivity will depend upon change of temperature, precipitation, solar radiation and fertilization. Particularly, nitrogen fertilization considerably influences rice productivity and agricultural environments. This experiment was conducted to study transformation of nitrogen and to determine the primary yield components responsible for yield differences in paddy soil. $NH_4-N$ concentration of NPK plot in surface water of paddy soil was $2.07mg\;L^{-1}$ at 5 days after transplanting, and then was decreased sharply due to rice absorption and loss to environment. $NO_3-N$ concentration of NPK plot in surface water was $3.97mg\;L^{-1}$ at 10 days after transplanting. $NO_3-N$ concentration range of CRF plot in surface water was $3-5mg\;L^{-1}$ at 30th after transplanting. The accumulation of $NH_3$ volatilization in NPK plot was $22.39kg\;ha^{-1}$, which accounted for 20% of N fertilizer applied but using of CRF fertilizer can reduce $NH_3$ volatilization by 67% in paddy soil. Use efficiency of N fertilizer was not different between CRF70% and CRF100% plot. Rate of N use efficiency were 27.4%, 51.2%, 49.0% in paddy field NPK, CRF70% and CRF100% plots respectively. The yield of CRF70% showed the best effect with 9.3% increase production ratio, compare with NPK plot.