• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.829-846
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• 2015

This study was conducted to determine the effects of organic fertilization rates on the nutrient accumulation and recovery in radish (Raphanus sativus L.) as well as growth and yield of radish in Jeju island. An understanding the relationships between organic fertilization rate, crop nutrient recovery and crop yield can assist in making organic fertilizer recommendation which balances crop value and environmental risk in organic cultivation. Nitrogen (T-N), phosphate ($P_2O_5$) and potassium ($K_2O$) were applied at 0, 115-35-40, 230-70-80 (standard application rate), 460-140-160, 230-200-100 (recommended application rate) and 158-53-35 kg/ha (customary application rate), respectively as the broadcast application of mixed organic fertilizer (N 4.5% - $P_2O_5$ 1.5% - $K_2O$ 1%) in combination with langbeinite ($K_2O$ 22%), 100% at sowing period. The organic fertilizer was made of organic materials like oil cakes. Total yield of radish, as fresh weight of roots, increased with increasing organic fertilizer doses to a maximum at rate of standard or soil-testing application. Nitrogen, phosphate and potassium accumulations of radish increased curvilinearly with increasing organic fertilization rate to a maximum at rate of N 460 - $P_2O_5$ 140 - $K_2O$ 160 kg/ha. However, nitrogen, phosphate and potassium use efficiency of applied organic fertilizer decreased curvilinearly or linearly with increasing organic fertilization rate. Application of organic fertilizer in combination with langbeinite (as a potassium source) had significant effect on the yield of radish. Organic fertilization on a basis of standard or soil-testing application rate is recommended for maximun radish yield in organic cultivation.

• Korean Journal of Organic Agriculture
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• v.27 no.2
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• pp.173-191
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• 2019

The study was initiated to compare seasonal nutrient variations and rice (Oryza sativa L.) productivity in each of leading rice farm with conventionally managed and recommended fertilized of the large-scale environment-friendly agricultural districts in Jangheung, Suncheon, and Okcheon provinces in 2017. Suncheon rice experimental farm plots included a recommended fertilization plot that had been additionally sown hairy vetch in the fall of previous year, while Okcheon rice farm included a recommended fertilization plot applying half amount of the compost in the conventional plot. A Jangheung rice farm only practiced crop-livestock farming system. Soil pH and EC in all experimental plots were suitable levels for rice growth to cultivate. Seasonal soil pH from March to September was the highest for Suncheon rice farm, and seasonal soil EC was the highest for Jangheung rice farm. Seasonal soil T-N increased in all the plots from March to June in particular for Suncheon rice farm, and Jangheung rice farm had the lowest seasonal soil P. Seasonal soil K decreased in all the plots, with the lowest levels observed for Okcheon farm. Seasonal soil NH₄⁺ mostly increased by up to 90 mg/kg in Jangheung rice farm from March to June. Seasonal plant T-N, P and K concentrations were the highest for Jangheung rice farm. Seasonal plant T-N and P concentrations decreased from June to September, but K leveles were fluctuated between 2.0% and 2.5%. Seasonal SPAD value was the lowest in Suncheon conventional plot. Jangheung rice farm plot produced 6,303 kg of rice per ha, which was approximately two times higher than those of Okcheon recommended plot. The seasonal T-N, P and K balance was the highest in Okcheon conventional plot, with the lowest values observed for Suncheon conventional plot. As a result, Suncheon recommended plot showed relatively low levels of seasonal macro-nutrient balance and the highest rice production, which could be the most environmentally friendly farm practiced conducted in this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.65-71
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• 2008

The effect of rice bran (RB) applied alone or in combination with chemical fertilizer at different application rate on the phytochemical and antioxidant properties of rice was investigated. The treatments were 3 levels of RB namely: 200% RB (500 kg $10a^{-1}$), 100% RB (250 kg $10a^{-1}$), 50% RB (125 kg $10a^{-1}$), Recommended fertilizer dose (RF: $N-{P_2}{O_5}{K_2}O$, 11-5.5-4.8 kg $10a^{-1}$) combined with each RB, Half-recommended fertilizer dose (HRF: $N-{P_2}{O_5}{K_2}O$, 5.5-2.75-2.4 kg $10a^{-1}$) combined with each RB, RF and HRF applied at 1, 5, 10 days before rice transplanting (DBT). The parameters investigated were antioxidant, phytosterol and fatty acid contents. Results showed that the antioxidant property and phytosterol contents were high at 10 DBT HRF plus RB, 5 DBT RF plus RB, and 1 DBT 100 and 200% RB. However, total polyphenols increased from 10 to 1 DBT. In the case of fatty acids, no general trend was observed between treatments at different application times. Linoleic acid was high at 10 DBT HRF plus RB while linolenic acid was not affected at different application times. Palmitoeic and oleic acids were not also affected at 5 and 10 DBT. Saturated fatty acids were not also affected by any treatment at different application times except for palmitic acid.Most parameters obtained higher values at 100 and 200% RB treatments in 1 DBT.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.4
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• pp.234-239
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• 2014

This experiment was conducted to evaluate the effect of seeding rates on the forage quality and productivity of direct-seeded whole crop rice at the experimental field of the Grassland and Forages Division, National Institute of Animal Science, RDA from 2007 to 2008. Whole crop rice variety, "Nokyang", developed by the National Institute of Crop Science, was directly seeded with four different seeding rates (30, 60, 90 and 120 kg/ha). There were no significant differences (p<0.05) found in emergence date, heading date, greenish and disease resistance based on the seeding rates. Plant height increased at higher seeding rates but the tiller number per plant decreased (p<0.05). The dry matter (DM) content showed no significant difference based on seeding rates (p<0.05) while the yield of fresh and dry matter increased with incremented seeding rates (p<0.05). Acid detergent fiber (ADF) content increased with higher seeding rates, but the neutral detergent fiber (NDF) content did not show a similar tendency. The total digestible nutrient (TDN) content was lowest with 120 kg/ha seeding rate. The grain ratio decreased at higher seeding rates. In economic analysis, the plot seeded at a rate of 60 kg/ha showed the highest income increment. Although high seeding rates increased the DM yield, a seeding rate of 60 kg/ha is recommended as the proper seeding rate for direct-seeded whole crop rice.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.3
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• pp.37-44
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• 2020

The Project supporting organic fertilizer started in 1999 as a national policy. In farmhouse, over application of mixed organic compound fertilizer(OC) caused salt accumulation in plastic film house soil. To replace inorganic fertilizer with OC fertilizer, this study was investigated the effect of OC application on yield and soil chemical properties for lettuce cultivation in plastic film house. The OC fertilizer was applied at 50(OC50+N50), 100(OC100), and 150(OC150) % level of the basal amount of nitrogen fertilizer in soil testing recommendation. And these were compared to NPK(nitrogen, phosphat, and potash fertilizer) and PK treatment. The yield of lettuce in OC100 was similar to that of NPK treatment. In OC 50, 100 and 150 treatments, pH had a tendency to increase than that of NPK treatment. Nitrate nitrogen(NO₃-N) and electrical conductivity(EC) were similar to NPK treatment. These showed that nutrients from OC fertilizer were less likely to accumulate in soil than NPK. Also, use efficiency of nitrogen in OC100 treatment were similar to NPK treatment. These results suggest that OC application as the basal dressing at the 100% level could be best to prevent a nutrient accumulation of soil and to increase the yield and commercial quality for lettuce.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.301-308
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• 2004

This experiment was carried out to classify heading date of forage rye cultivars, and study agronomic characteristics, dry matter yield per ha and forage quality of winter rye cultivars in Suwon for 2 year from 2002 to 2003. The earliest cultivars among forage winter rye cultivars were Olhomil and Vitagrazer, which the heading date was April 21. The latest cultivar was Danko, which was May 5. Koolgrazer was April 26 and Homil 22 was April 30, respectively. Therefore, we classified the cultivars into three groups according to their heading date. The earliest group includes Olhomil, Vitagrazer, Paldanghomil, the middle group includes 5 cultivars which are Koolgrazer, Barrgazer, Maton, Wintergrazer and Homil22, and the latest group contains Humbolt and Danko. The number of tiller per $m^{2}$ of most cultivars were more than 1,000. The cultivar which has lowest tiller was Humbolt, which dry matter yield was the largest, and its tiller was 789. The lodging happened after each precipitation. Danko was the cultivar that has lowest lodging frequency. There has been little disease and insect and the difference in the quality of each cultivar. The yield of dry matters per ha of Humbolt was increased $123\%$, Vita grazer $121\%$, Maton $113\%$ comparing the standard cultivar, Kool grazer of 12,409kg, and Homil 22 was almost the same with the standard cultivar.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.135-140
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• 1988

This field experiment was carried out to determine the effects of cutting times (3,4 and 5 times $yr^{-1}$) and cutting heights (3, 6 and 9 cm) on the growth and dry matter(DM) yield of grasses grown under pine trees, and botanical composition of woodland pasture. The conditions of the experimental field was south direction with 30% of shade (ca. 70% of full sunlight). Annual DM yield was higher in the plots cut 4 times (6,097 kg) and 3 times (5,953 kg) than in 5 times (5,305 kg $ha^{-1}$). However, it ip considered that total nutrient yields may be not different among 3 treatments. The yield was significantly (P < 0.05) increased with higher cutting height, regardless of cutting time. The 9 cm of stubble height was very effective on both increasing DM production and seasonal distribution of DM. In botanical composition, 3 cm and 6 cm of cutting height accelerated the percentages of bareland and weeds, regardless of cutting time, particularly in summer season. However, 9 cm of stubble height maintained 80-85% of pasture grasses in all cutting times. In this experiment, therefore, cutting height was more important factor than annual cutting times for forage production and pasture longevity, and it is desirable to harvest 4-5 times per year (under this experimental field condition) with 9 cm of stubble height on woodland pasture.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.223-227
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• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.4
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• pp.202-210
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• 2005

Since understanding on spatial variability of a field is essential to pursue precision agricultural technology, a field study for field variability and variable rate fertilization of nitrogen in a direct seeding paddy was attempted. Variable rate application of nitrogen was designed with soil test, and field application was tested in a direct seeding paddy in the Kimje, Jeonbuk, Korea. The grid samples of soil was collected from the field of which unit size was 35 m by 112 m on February before irrigating of the field. Soil organic matter, available phosphate and silicate, and extractable potassium were analyzed. Variable rate fertilizer recommendation maps of nitrogen for high yielding, HY, and low input sustainable agriculture, LISA, were derived based on the soil analysis. Direct seeding of rice was performed for variable rate treatment, VRT, for the experimental plot in 2001 and 2002, and so did for three volunteer farmers' field in 2003. Yield mapping was performed by harvesting. Economic feasibility of direct seeding of rice by variable rate fertilization was evaluated. Though increased yield of variable rate application and benefit of reducing fertilizer use and environmental impact, the cost for soil test exceeded the total reduced fertilizer cost.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.4
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• pp.107-113
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• 1981

In order to investigate effects of fertilization on the yield of chestnut trees and to compare the compound fertilizer (CF) and Boron contained compound fertilizers (BCF) for chestnut trees developed by Chosun Fertilizer Inc. with single fertilizers (SF) at different fertilizing levels, a field experiment was conducted during the 1979 and 1980 growing periods. The results were summarized as follows: 1. The growth of chestnut trees was markedly improved as increasing the amount of fertilizers regardless of the SF, CF or BCF. 2. The number of strobiles increased as increased amount of fertilizers, and the ratio of dropped strobiles decreased by more than 90 percent by the BCF application while that decreased by 12 to 47 percents by the SF or CF applications. It implies that the boron application be necessary for increasing strobiles and reducing the ratio of dropped strobiles. 3. The yield increments by the SF or CF applications at the standard level were 80 percent and that by the BCF application at the same level was 202 percent and the highest yield increment was recorded as high as 302 percent by the BCF application at the doubled level in 1979. The yield response in 1980 was similar to that in 1979; however, the yields were lower than in 1979 due to the abnormal weather conditions such as low temperature and low solar radiation during summer except BCF applicated treatments where the yields were outstandingly increased. 4. The BCF developed proved as a recommendable compound fertilizer for chestnut trees.