• Journal of The Korean Society of Grassland and Forage Science
• /
• v.5 no.3
• /
• pp.200-206
• /
• 1985

This field experiment was undertaken to assess the effects of three levels of inclination ($10^{\circ},\;20^{\circ},\;and\;30^{\circ}$) and four rates of $N-P_2O_5-K_2O$ (0-0-0-, 14-10-10, 28-25-25, and 42-40-40kg/10a) on establishment, yield and quality, and botanical compositions of mixed grass-clover sward. This second part is concerned with the soil chemical properties, concentrations and uptake of mineral nutrients, and percent recovery and efficiency of NPK. The results obtained after a two-year experiment are summarized as follows: 1. The pH, exchangeable Mg and Na, and base saturation in the surface soils were decreased by increasing the grade of inclination, whereas organic matter and available $P_2O_5$ tended to be increased. However, the changes in the Ca content and equivalent ratio of $K\sqrt{Ca+Mg}$ were not significant. The pH, exchangeable Ca and Mg, and base saturation were reduced by increasing the NPK rate, whereas available $P_2O_5$, exchangeable K, and equivalent ratio of $K\sqrt{Ca+Mg}$ tended to be increased. 2. The concentrations of mineral nutrients in grasses and weeds were not significantly affected by increasing the grade of slope in hilly pasture, whereas the concentrations of N, K, and Mg in legume were the lowest with the steep slope, which seemed to be related to the low legume yield. The Mg concentrations of all forage species were below the critical level for good forage growth and likelihood of grass tetany. 3. The increase of NPK rate resulted in the increment of N, K and Na concentrations, and the decrease of Mg and Ca in grasses. The P concentration was increased with P application, but there were no differences in that among the P rates applied. It resulted also in a slight increase of K, and a decrease of Mg in legume, but the contents of N, Ca, and Na were not affected by that. On the other hand, it has not affected the mineral contents in weeds except a somewhat increase of N. The mixed forages showed a increase of N and K contents, a decrease of Ca and Mg, and a slight change in P and Na. 4. The percent recovery of N, P and K by mixed forages were greatly decreased by increasing the grade of inclination and NPK rate. They were high in the order; K>N>P. The efficiency of mixed NPK applications was decreased by that. The efficiency of mixed NPK fertilizers absorbed was slightly decreased by the increased rate of NPK, but it was not affected by the grade of inclination.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.5
• /
• pp.407-428
• /
• 1991

The eastern coastal area having variability of climate is located within Taebaek mountain range and the east coast of Korea. It is therefore ease to cause the wind damages in paddy field during rice growing season. The wind damages to rice plant in this area were mainly caused by the Fohn wind (dry and hot wind) blowing over the Taebaek mountain range and the cold humid wind from the coast. The dry wind cause such as the white head, broken leaves, cut-leaves, dried leaves, shattering of grain, glume discolouration and lodging, On the other hand the cold humid wind derived from Ootsuku air mass in summer cause such symptom as the poor rice growth, degeneration of rachis brenches and poor ripening. To minimize the wind damages and utilize as a preparatory data for wind injury of rice in future, several experiments such as the selection of wind resistant variety to wind damage, determination of optimum transplanting date, improvement of fertilizer application methods, improvement of soils and effect of wind break net were carried out for 8 years from 1982 to 1989 in the eastern coastal area. The results obtained are summarized as follows. 1. According to available statisical data from Korean meteorological services (1954-1989) it is apperent that cold humid winds frequently cause damage to rice fields from August 10th to September 10th, it is therefore advisable to plan rice cultivation in such a way that the heading date should not be later than August 10th. 2. During the rice production season, two winds cause severe damage to the rice fields in eastern coastal area of Korea. One is the Fohn winds blowing over the Taebaek mountain range and the other is the cold humid wind form the coast. The frequency of occurrence of each wind was 25%. 3. To avoid damage caused by typhoon winds three different varieties of rice were planted at various areas. 4. In the eastern coastal area of Korea, the optimum ripening temperature for rice was about 22.2$^{\circ}C$ and the optimum heading date wad August 10th. The optimum transplanting time for the earily maturity variety was June 10th., medium maturity variety was May 20th and that of late maturity was May 10th by means of growing days degree (GDD) from transplanting date to heading date. 5.38% of this coastal area is sandy loamy soil while 28% is high humus soil. These soil types are very poor for rice cultivation. In this coastal area, the water table is high, the drainage is poor and the water temperature is low. The low water temperature makes it difficult for urea to dissolve, as a result rice growth was delayed, and the rice plant became sterile. But over application of urea resulted in blast disease in rice plants. It is therefore advise that Ammonium sulphate is used in this area instead of urea. 6. The low temperature of the soil inhibits activities of microorganism for phosphorus utilization so the rice plant could not easily absorb the phosphorus in the soil. Therefore phosphorus should be applied in splits from transplanting to panicle initiation rather than based application. 7. Wind damage was severe in the sandy loamy soil as compared to clay soils. With the application of silicate. compost and soil from mointain area. the sand loamy soil was improved for rice grain colour and ripening. 8. The use of wind break nets created a mocro-climate such as increased air. soil and water temperature as well as the reduction of wind velocity by 30%. This hastened rice growth, reduced white head and glume discolouration. improved rice quality and increased yield. 9. Two meter high wind break net was used around the rice experimental fields and the top of it. The material was polyethylene sheets. The optimum spacing was 0.5Cm x 0.5Cm. and that of setting up the wind break net was before panicle initiation. With this set up, the field was avoided off th cold humid wind and the Fohn. The yield in the treatment was 20% higher than the control. 10. After typhoon, paddy field was irrigated deeply and water was sprayed to reduce white head, glume discolouration, so rice yield was increased because of increasing ripening ratio and 1, 000 grain weight.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.4
• /
• pp.311-322
• /
• 2019

In order to establish an optimal double cropping system to obtain the maximum annual quantity, we investigated the annual productivity of whole-crop silage (WCS) rice, Jowoo (Jw), Yeongwoo (Yw), and Mogwoo (Mw), and winter feed crops (WFC), Italian ryegrass (IRG), Greenfarm (GF), rye Gogu (GU), and triticale Joseong (JS), in paddy fields of the central plains of Korea. From 2016 to 2019, each crop was subjected to two standard cultivation methods: WCS rice and WFC optimal. Using the WCS optimal mode, the average dry matter yield (DMY) of WCS rice, early flowering Jw, was 15.8 tons/ha and 21.0 for the mid-late heading Yw; there was no significant difference compared to the 19.2 tons/ha late-flowering Mw (p<0.01). The WFC were not significantly different between GF (3.2 tons/ha) and GU (4.5) sown on September 23rd, while JS was the highest at 12.6 tons/ha (p<0.001). There was a significant difference in the order of JS (16.6 tons/ha) > GF (10.5) > GU (4.7)(p<0.001) sown on October 11th. For JS sown on October 31st, the DMY was 11.8 tons/ha, which was significantly higher than that of the other two crops (p<0.05). Except for rye GU, DMY was the highest when sown on October 11th. For WFC optimal mode, the average DMY of JS was the highest at 18.3 tons/ha, which was significantly different from that of GF (10.9) and GU (9.6) (p<0.001). The DMY of WCS rice transplanted on May 10th was the highest at 23.0 tons/ha in Mw, which was not significantly different from that of Yw (21.4) but significantly different from that of Jw (15.9) (p<0.05). On transplanting on May 25th, the DMY of Mw was the highest at 24.2 tons/ha; this was not significantly different from that of Yw (20.7), but it was significantly different from that of Jw (18.6) (p<0.05). When transplanted on June 11th, the DMY was 21.3 tons/ha in Yw, which was significantly higher than the DMY of other two cultivars, Jw and Mw (p<0.05). For the WCS rice-WFC double cropping, the total annual DMY was 33.6 tons/ha with the combination of the WCS rice, Yw, and the triticale JS for WCS optimal mode. Meanwhile, the total annual DMY was 39.6 tons/ha with the combination of the triticale JS and the WCS rice, Yw, for WFC optimal mode. In conclusion, the strategies for obtaining the maximum yield of high-quality forage for WCS rice-WFC, WFC-WCS rice double cropping are as follows: 1) cultivation centered on the optimal mode of WFC, and 2) sowing the WFC, triticale JS in mid-October, harvesting the crops around the end of May and transplanting the WCS rice, Yw, in early June to obtain the maximum DMY of 39.6 tons/ha.

• Korean Journal of Organic Agriculture
• /
• v.17 no.3
• /
• pp.371-380
• /
• 2009

This study was conducted to assess effects of supplying different types of nitrogen sources as fertilizers on productivity and feed values of barley and rye as winter forage crops, and ultimately done to get good quality of organic forages with higher fertilization of soil. For barley, N+P+K plots were significantly (P<0.05) higher in annual dry matter (DM) and total digestible nutrients (TDN) yields than other plots. However, cattle manure plots had significantly (P<0.05) higher annual DM and TDN than P+K and non-fertilizer plots. Plots of 50%-cattle manure and mixed sowing with hairy vetch or forage pea were higher than only 50%-cattle manure plot, particularly, these were significantly higher than non-fertilizer, and their crude protein (CP) yields were much higher than other plots. Crude protein contents were significantly higher in N+P+K and 50%-cattle manure slurry plots than non-fertilizer and P+K plots, and plots of mixed sowing with hairy vetch or forage pea in application of 50%-cattle manure had higher CP content than other plots. ADF content was lowest in 50%-cattle manure+forage pea plots, but highest in 100%-cattle manure plots. NDF content was lowest in legumes-mixed sowing, but highest in 100%-cattle manure plots. TDN content was the highest in forage pea plots, and plots of 50%-cattle manure and legumes-mixed sowing had high RFV, but cattle manure plots rich in ADF and NDF content had the lowest TDN and RFV. For rye, plots of 50%-cattle manure+hairy vetch mixed sowing, and N+P+K application had significantly higher annual DM, CP and TDN than other plots except for cattle manure. DM productive efficiency to nitrogen fertilization was markedly higher for cattle manure plots than for chemical fertilizer. This tendency was more conspicuous in plots of 50% cattle manure+legumes-mixed sowing. CP content was higher for N+P+K plot than for all plots, and plots of 50%-cattle manure + legumes-mixed sowing were significantly higher than other plots. On the contrary, forage pea-mixed sowing plot had the lowest ADF and NDF, but TDN and RFV were significantly (P<0.05) higher than other plots. Grass crop cultivation together with legumes by applying livestock manure to soil may lead to higher palatability of livestock, and better quality of forage. Furthermore, cattle manure application increased production yield per ha and CP contents. Thus, when applying forage crops produced by cattle manure application and mixed sowing to organic livestock production, it was conceived that forages produced might become a substitute for foreign organic grain as protein sources.

• Korean Journal of Breeding Science
• /
• v.41 no.4
• /
• pp.654-659
• /
• 2009

"Cheongcheongjinmi" is a new japonica rice variety developed from a cross between Iri401 and Ilpumbyeo by the rice breeding team of National Institute of Crop Science, RDA. This variety is suitable for ordinary season culture of low level nitrogen application. Heading date of "Cheongcheongjinmi" is August 17, 4 days later than that of Sobibyeo in plain areas. It has culm length of 82 cm, and relatively semi-erect pubescent leaf blade and slightly tough culm tolerant to lodging with good canopy architecture. This variety has 13 tillers per hill, 126 spikelets per panicle and 90.2% of ripened grains. "Cheongcheongjinmi" showed lower spikelet fertility than Sobibyeo when exposed to cold stress. This variety showed slower leaf senescence and lower viviparous germination compared to Sobibyeo during the ripening stage. "Cheongcheongjinmi" is susceptible to blast disease, bacterial blight, virus diseases and planthoppers. The dried plant weight, total nitrogen and RuBisCO activity of "Cheongcheongjinmi" were higher than those of Sobibyeo in low level nitrogen application. The milled rice of "Cheongcheongjinmi" exhibits translucent, clear non-glutinous endosperm and medium short grain. It shows lower protein and amylose contents than those of Sobibyeo, and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.10 MT/ha at low level nitrogen application of ordinary season culture in local adaptability test for three years. Especially, "Cheongcheongjinmi" has better milling properties such as the percentage of whole grain in milled rice and milling recovery of whole grain, respectively than those of Sobibyeo. "Cheongcheongjinmi" would be adaptable to middle plain areas and middle-western coastal areas of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.4
• /
• pp.283-290
• /
• 1982

Sardine and mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapid dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added Ivith adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric onstant $(\varepsilon')$ and dielect.ic loss $(\varepsilon")$ values of sardine meat paste were influenced by wavelength and moisture level. Those values at 100 KHz and 15 MHz were ranged 2.25-9.86; 2.22-4,18 for E' and 0.24-19.24; 0.16-1.20 for E", respectively, at the moisture levels of $4.2-13.8\%$. For a formula for fish-starch paste preparation, addition of $20-30\%$ starch (potato starch) to the weight of fish meat, $2-4\%$ salt, and $5-10\%$ soybean protein was adequate to yield 4-5 folds of expansion in volume when heated. Addition of e99 yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of $0.2-0.5\%$sodium bicarbonate, foaming agent, was proper to result in foam size of 0.5-0.7 mm and foam density of $200-400\;/cm^2$ which gave a good crispness. Heating time was depended upon the moisture level of fish-starch paste. For a finger shaped paste (1.0cm. $D\times10cm.L$) heating for 150-200 sec. in a microwave oven (700W. 2.45GHz) was sufficient to generate foams, expand, and solidify the porous structure of fish-starch paste. When the moisture content was above $55\%$ browning and scorching was deepened due to over-expansion and over-heating whereas the crispness was hardened by insufficient expansion at lower moisture content. In quality evaluation of the product, chemical composition of $30\%$ starch and $3\%$ salt added product was moisture $8.8\%$, lipid $2.4\%$, carbohydrate $46.7\%$, protein $36.1\%$, and ash $6.0\%$. Eleven membered panel test evaluated that fish-starch paste was acceptable in color, crisp-ness, taste, except a trace of fishy odour which could be masked by the addition of spice extracts.

• Korean Journal of Breeding Science
• /
• v.40 no.4
• /
• pp.443-446
• /
• 2008

'Gangbaek' is a japonica rice variety developed and registered by the rice breeding team of Department of Rice and Winter Cereal Crop, NICS, RDA in 2006. 'Gangbaek' was derived from a cross between 'Suweon345' with good grain quality and 'DV85' resistant to bacterial blight, $K_{3a}$. $F_1$ plants were grown in the greenhouse in winter of 1992/1993 and backcrossed with 'Suweon345' as the recurrent parent. Plants resistant to $K_{3a}$ race of bacterial blight (BB) were selected from $BC_1F_1$ to $BC_4F_1$ and used as parents in the backcrossing processes. This variety has about 120 days growth duration from transplanting to harvesting in west-southern coast and Honam plain of Korea. It is about 69 cm in culm length and tolerance to lodging. In reaction to biotic and abiotic stresses, it shows moderately resistance to blast, and resistance to bacterial blight pathogen, $K_1$, $K_2$, $K_3$ and $K_{3a}$, but susceptible to other major diseases and insect pests. The milled rice of 'Gangbaek' exhibits translucent, relatively clear non-glutinous endosperm and midium short grain. It has lower amylose content of 18.6% and protein content of 6.4% compared with 'Nampyeongbyeo'. The milled rice yield performance of this variety is about 5.28 MT/ha in local adaptability test for three years. This cultivar would be adaptable to the bacterial blight-prone area in the south-western coastal and Honam plain of Korea.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.18 no.1
• /
• pp.13-24
• /
• 2016

Sixty Hanwoo steers(15 months of age; 409±29.2 kg of BW) were used to evaluate the effects of dietary vitamins A and D restriction on carcass characteristics. Steers were allotted randomly to 1 of 4 treatments: Control(diet supplemented with vitamins A, D and E), -A (diet supplemented with vitamins D and E), -D(diet supplemented with vitamins A and E) and -AD(diet supplemented with vitamin E only). Steers were fed the experimental diet for a period of 8 months(until 23 months of age), and then supplemented with vitamins A and D at 0.05% of the diet(as fed-basis) from 24 to 26 months of age, and at 0.1% of the diet from 27 to 31 months of age(harvesting time). Dietary restriction of vitamins A and D did not affect DM intake, daily gain and feed conversion ratio. But the concentration of serum retinol was significantly(P<0.05) decreased by vitamin A restriction with the lowest concentration being seen at 23 months of age(345.0 ㎍/L and 326.7㎍/L for control and -D treatment versus 169.3 ㎍/L and 175.4 ㎍/L for -A and -AD treatments). The serum concentration of 25(OH)D₃ was also decreased significantly(P<0.05) by vitamin D restriction and the lowest concentration was seen at 18 months of age(53.7ng/ml and 61.8ng/ml for control and - A treatment versus 24.0 ng/ml and 24.5 ng/ml for -D and -AD treatments). After the restriction period of vitamins A and D, the concentrations of retinol and 25(OH)D₃ for - A, -D and -AD treatments were recovered at those of control. Dietary restriction of vitamins A and D did not affect carcass weight, backfat thickness, ribeye area, quality grade and yield grade. But marbling score was significantly increased by vitamin A restriction compared with control(6.73, 6.87 and 5.73 for -A, -AD and control, respectively). The results of the present study suggested that dietary vitamin A restriction could improve marbling score in Hanwoo steers.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.6
• /
• pp.369-377
• /
• 2005

Precise application of topdressing nitrogen (N) fertilizer is indispensible for securing high yield and good quality of rice and minimizing N losses to the environment as well. For precise N management, growth and nitrogen nutrition status (NNS) should be diagnosed rapidly and accurately. The objective of the study was to evaluate the applicability of vegetation index (VI) calculated from hyperspectral canopy reflectance measurement and SPAD reading to nondestructive in situ diagnosis of growth and NNS of rice. Canopy reflectance, SPAD read­ing, growth parameters, and NNS characteristics were measured from various N treatments to evaluate the relationships among them for two cropping seasons from 2001 to 2002. The correlation coefficient of VIs with variables of growth and NNS increased positively as rice canopy became more closed. Regardless of growth stages, VIs had significantly high correlations with LAI, shoot dry weight (DW), shoot N content and nitrogen nutrition index (NNI). Those correlation coefficients increased steadily before heading stage as rice grew up. However, tiller number and leaf N concentration showed significantly high correlations with VIs only at and after panicle initiation stage (PIS). Among the VIs, RVIgreen had significantly higher correlation with the measured parameters than the other VIs: it showed correlation coefficients greater than 0.8 with leaf and shoot N concentration and DW, and much higher coefficients greater than 0.9 with LAI, shoot N content, and NNI. At LAI of below 2.5, VIs had non-significant or low correlations with the growth and NNS indicators due to the background effects. SPAD reading had significantly high correlation with leaf N concentration and NNI at each growth stage. In addition, it had significant correlations with variables of growth and NNS at PIS and booting stage, particularly, at booting stage. Though SPAD reading had a significantly high correlation value at a given growth stage in each year, it showed very weak relationship with variables of growth and NNS when pooled across growth stages and years. In conclusion, RVIgreen was found to be the most reliable VI to estimate the growth and NNS of rice around at PIS, but SPAD reading had much limitations.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.37 no.4
• /
• pp.254-263
• /
• 2017

This study was carried out to introduce of agronomic characteristics, forage yields and quality of Sorghum ${\times}$ Sudangrass hybrids 'Cadan 99B' and 'Sweet Sioux WMR' from 2015 to 2016 in middle and southern regions of Korea. The field experiment design was complete in seven varieties with three repetitions. Sorghum ${\times}$ Sudangrass hybrids were sown on mid-May in middle region, and end-May in southern region of Korea, in 2015 and 2016. The observed average heading date of Cadan 99B and Sweet Sioux WMR were July 22. The heading dates of Cadan 99B and Sweet Sioux WMR were 8 days earlier than SX-17 and 5 days earlier than brown mid-rid (BMR) Revolution. The sugar contents of Cadan 99B and Sweet Sioux WMR were 6.5 and $6.9Brix^{\circ}$, respectively. Comparison with BMR variety, the sugar contents of Candan 99B and Sweet Sioux WMR were 0.2 and $0.6Brix^{\circ}$ higher than Revolution, respectively. The average of dry matter (DM) yield for 2 years and 2 regions of Cadan 99B (24,587kg/ha) were the highest among the seven varieties, but there was no significant difference among other varieties except headless control variety Jumbo (19,119kg/ha) and LATTE (20,778kg/ha) (p>0.05). The crude protein (CP) and in vitro dry matter digestibility (IVDMD) of Cadan 99B were 7.5% and 60.2%, and Sweet Sioux WMR were 6.9% and 60.7%, respectively. The results of this study indicated that Sorghum ${\times}$ Sudangrass hybrids Cadan 99B and Sweet Sioux WMR are earlier heading dates and higher than SX-17, and high yields of DM in middle and southern regions of Korea.