• KOREAN JOURNAL OF CROP SCIENCE
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• v.14
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• pp.111-115
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• 1973

This experiment was carried out to study the effects of planting density and amount of fertilizer applied on the morphological, physiological and physical characteristics of barley culm. The results are summarized as follows: 1. Heavy application of fertilizer increased the diameter of the inside and outside thickness of culm, dry weight per unit culm, culm length, spike weight and number of per hill. 2. Thined planting density increased lodging resistance. But lodging resistance in sparse-planted plot of$20{\times}$ 20cm was almost the same as that in the plot of $15{\times}$ 15cm. 3. In the heavy fertilized plot weight of culm at breaking, bending moment of culm atbreaking, secondary moment of inertia and section modulus increased more than those in the standard fertilized one. As a result heavy application of fertilizer gave high lodging resistance. On the other hand thined planting density increased the above-mentioned physical characters of culm. 4. In the case of dense planting lodging index became higher in standard fertilized plot, but in the case of sparse planting over 10 x 10cm there were no significant differences in lodging index as affected by amount of fertilizer applied and planting density. 5. Grain yield was increased by heavy application of fertilizer and proper planting density was $5{\times}$ 5cm or $10{\times}$10cm for the safe maximum yield.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.1
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• pp.40-43
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• 1990

Study was conducted to investigate the optimum amount of nitrogen fertilizer for the green forage production of Italian ryegrass at the paddy field after rice harvesting in southern part of Korea in 1987 and 1988. Effects of three levels of nitrogen fertilizer application (15, 30 and 45 kg N/10a) on the green yield and nitrate content of green forage at three cutting times (April 30, May 20 and June 10) were examined in 1988. The results were as follows. 1. Yield of green forage at all cutting times increased in order of 45 > 30 > 15 kg N/10a, and it increased about 14 percent in the 45 kg N/10a and decreased about 35 percent in the 15 kg N/10a compared with the 30 kg N/10a. 2. Nitrate content in the green forage at all cutting times was high with increasing amount of nitrogen fertilizer and with decreasing ratio of K/(Ca+Mg) in green forage. The nitrate content at the second and the third cutting times in the 45 kg N/10a might be outrunned the tentative limitation for cattle. 3. Maximum amount of nitrogen fertilizer was 48 kg/10a for total green forage production, but it was 38 kg/10a near at cattle's harmful limit of nitrate content in green forage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.123-123
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• 2022

In order to evaluate the effect of nitrogen application levels on yield and protein content of rice varieties, a field experiment was conducted at National Institute of Crop Science of Korea in 2020. Five levels(0, 3, 5, 7, and 9 kg·10a^-1) of nitrogen fertilizer were treated to six Korean rice varieties. The nitrogen uptake amount, soil nitrogen content before and after rice cultivation, milled rice yield, and protein content in head rice were analyzed. As the treatment of nitrogen fertilizer increased, the nitrogen uptake amount of plants increased significantly. However, changes in nitrogen content in the soil before and after rice cultivation were different for each cultivar. The amount of nitrogen change in the soil decreased as the amount of nitrogen application increased in the three cultivars of Haepum, Gopum, and Odae, and the other three cultivars showed the opposite trend. As a result of correlation analysis of nitrogen application amount, nitrogen uptake amount, milled rice yield, and protein content of head rice, the five varieties except for Haepum showed a high correlation between these factors. The amount of nitrogen application and nitrogen uptake of plant showed a positive correlation about the milled rice yield and protein content of head rice. In particular, the protein content in head rice appeared to be more affected by nitrogen uptake amount than nitrogen application amount. As a result of this study, the yield and protein content of rice had positive correlations with the level of nitrogen fertilizer, and had a high correlation with the nitrogen absorption of plants.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.3
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• pp.149-163
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• 1976

In Korea, the ever-increasing population has become a serious problem and the decreasing of cultivated lard area per person has become a major concern. Therefore, today we are implementing a green revolution using miracle varieties which require more fertilizer. The increased use of fertilizer along with development and adoption of high yielding varieties is the key to carrying out this green revolution. Fertilizer consumption in Korea is mainly influenced by agricultural techniques, fertilizer prices and government policies for increasing food production. If there are no special change, such as a cataclysm or an exhaustion of resources, it is quite clear that the fertilizer demand will increase to the near maximum ceiling point of optimum levels for crops in the year 2000. Fertilizer demand is not the amount of fertilizer that will be used by the farmer, but the actual optimum amount of plant nutrients required for maximum production. In this report, two alternative strategies are consideded in forecasting the future feitilizer demands. Alternative I is projected by reviewing consumption amounts over the last 10 years (1966~75) in Korea. The annual rate of increase in fertilizer consumption for the last 10 years was approximately 8.7% (table 1). Plant nutrient consumption rates in later years have been more balanced, and also fertilizer consumption per total acreage is considerably higher in Korea than in other countries (table 11), consequently the rate of increase in the future is expected to decline. Looking at the long term projections, the average annual rate of increase is expected to be 7% for 1976~80, 2.5% for 1981~90, 1.5% for 1991~2000. Thus, total projected fertilizer demands are estimated at 1,208,000M/T by 1980, 1,547,000M/T by 1990, 1,795,000M/T by 2000 (table 16). Alternative II is based on projected optimum fertilizer levels for crops and on increased crop acreage. The government recommended fertilizer rate has increased by a factor of 0.99 to 5.49 over the past twelve years depending on the specific crops (table 4). Levels of fertilizer demand recommended by government (table 7) in 1976 are still low compared with actual optimum fertilizer demands for crops (table 5). Therefore, future incaeases in fertilizer usage are anticipated. Thus, total projected fertilizer demands are estimated at 1,229,000M/T by 1980, 1,493,000M/T by 1990 and 1,898,000M/T by 2000(table 16).

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.594-597
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• 2014

Crop yields depend on the limiting factor of crop growth; Liebig law of minimum. Identifying the kind and the necessary amount of the limiting factor is essential to increase crop yield. Although nitrogen is the most essential nutrient, N application does not always bring about yield increases when other elements are limiting in rice cultivation. Two experiments were compared to elucidate the effect of soil testing on rice yield response to N level. The one was an experiment about yield response of 3 rice cultivars to 7 levels of N application, which was conducted from 2003 to 2004 in 25 farmer's fields without ameliorating soil conditions by soil testing and the other was a demonstration experiment on N fertilizer recommendation equation by 0, 0.5, 1.0, and 1.5 times of N recommended level in 5 soil types from 30 fields after ameliorating soil conditions by soil testing. The N response patterns of the experiments conducted without soil testing showed a Mitscherlich pattern in some cultivars and soil types, but did not in the others. The N response patterns of the demonstration experiment showed a Mitscherlich pattern in all soil types. Because these results indicated that N was the minimum nutrient in the demonstration experiment by ameliorating soil conditions with soil testing, but not in the other experiment without soil testing, the supply of minimum nutrients by soil testing could increase the efficiency of N-fertilization.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.153-162
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• 2013

Most test methods for plant available soil phosphate are based on the extraction with a chemical solution. The objective of this study is to evaluate available phosphate of various tests at different soil phosphate levels. Two experiments were conducted as follows: i) Extracting capacities of soil phosphate tests - Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Modified Lancaster(Mod. Lancaster) - were compared with that of Lancaster test for the soils collected from 32 paddy and 27 upland fields with various soil chemical properties. ii) Field trials on comparing to phosphate uptake by plant were accomplished by cultivating rice and corn plants in the pots filled with the soils. Available phosphate of Lancaster test was significantly correlated with those of Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Mod. Lancaster. In upland soils, available phosphates of all the tests were curvilinearly regressed with phosphate uptake by corn. The determination coefficients ($R^2$) of the regression equation between available phosphate in soils and phosphate uptake by plants were ranged from 0.861 (Mehlich III) to 0.741 (Olsen). In paddy soils, the available phosphate measured by Mehlich III and Lancaster was significantly correlated with phosphate uptake by rice. In conclusion, Lancaster and Mehlich III tests could be used for predicting available phosphate in upland and paddy soils.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.553-557
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• 2014

The steady increase in livestock industry has greatly required the stable production of food and forage crops. As an alternative, rice-forage cropping system has been attempted in several southern areas. The present study was performed to understand whether an application of cattle-manure compost affects soil chemical properties and crop productivity in rice-forage cropping system, rice ${\rightarrow}$ summer oat ${\rightarrow}$ rye, in Jangheong county, south Jeolla province from 2013 to 2014. Treatments was composed of control (no compost), CM1 (compost application before rice transplanting), and CM2 (two-times compost application, before rice transplanting and after rice harvest), and inorganic fertilizers (N, P, and K) were equally dressed in all plots. Yields of rice were not significantly different between treatments, however, oat production was 1.25-fold higher in CM1 and CM2. Nutrient uptake amounts of rye were higher in CM2 than CM1 and control. Total nitrogen in soil was maintained stable level during crop cultivation. And soil organic matter contents in all treatments were increased by crop residue. Available P_2O_5$ and exchangeable K were increased by cattle manure application. Therefore, it suggested that the amount of nutrient by forage crop residue should be considered in rice-forage multiple cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.165-172
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• 2001

Owing to raising number of livestock, we have a problem to solve disposal of livestock manure. We know that soil have the digestion ability of livestock manure as one of multifunctionality. I carried out to investigate of livestock manure digestion (especially pig and chicken manure) that is considered as nitrogen fertilizer in upland crops. The results were summarized as follows: 1. The amount of pig manure was(1999) 4,592,375 tons/year, and chicken manure was 4,488,166 tons/year and equivalent to 41,912 tons N/year and 76,223 tons N/year, respectively. 2. The definition of the digestion ability of livestock manure is as the maximum application amount of livestock manure without injuring soil and plant. And the calculation model of digestion ability of livestock manure(ALMD) is follows: ALMD = amount of nitrogen requirement per each upland crop / {(total nitrogen contents in livestock manure) ${\times}$ (nitrogen fertilizer efficiency of livestock manure)} 3. The amount of ability of pig and chicken manure for upland crops (dry based) were 1,142.9kg/10a and 540.1kg/10a, respectively. 4. The order of amount of digestion ability of livestock manure on upland were vegetables > orchards > miscellaneous grains(corn) > barley > potatoes > pulses > oil seeds & special crops ) fodder crops) mulberry.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.160-166
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• 2000

The reasonable level of nitrogen fertilizer of Gyokuro tea which is producted fresh leaves plucked from shade tea plants is a key factor to increase crop yield and quality. Nitrogen were applied at the level to 60, 80, 100 and $120kg\;10a^{-1}$. Analytical results of yield and quality of Gyokuro tea are summarized as follows : The soil fertility of experimental field was higher in organic matter($59.8g\;kg^{-1}$) and available phosphate($1,285mg\;kg^{-1}$), but lower in pH(4.79) compared to the common field. As the amount of nitrogen fertilizer application was increased to $80kg\;10a^{-1}$, the yield of tea leaves, the content of total nitrogen, total amino acid, caffeine and chlorophyll were increased. However, the yield of tea leaves was not increased above $100kg\;10a^{-1}$ and the increased level of nitrogen fertilizer did not show any different in the content of tannin and vitamin C. When the amount of nitrogen fertilizer application was raised, the content of thiamine and arginine increased, but the content of aspartic acid, serine and glutamic acid decreased. The content of fatty acid was produced $2.850{\sim}3.012mg\;100g^{-1}$ Especially, the content of oleic acid, linoleic acid and linolenic acid was higher at the level of $80kg\;10a^{-1}$ application than other treatments. As nitrogen was applied at $80kg\;10a^{-1}$, sensory score was 0.2~4.6 point higher than other treatments. Consequently, $80kg\;10a^{-1}$ is considered to be the best level of nitrogen fertilizer both quality and crop yield.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.71-81
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• 2019

This research was conducted to improve availability of agricultural by-products, national natural resources that could be used as fertilizer source, by estimating the amount of production and collecting main contents of fertilizer substances from previous studies and data, in order to be used as basic data to investigate national resources that could be used as alternatives for imported oil-cakes in the future. Conversion factor was used to estimate annual production of agricultural by-products for main 34 crop types in 2018. For total agricultural by-products, rice straws accounted at 50.3% for the highest proportion, followed by 8.7% of rice husks, showing that by-products from rice harvest accounted at 59.0% for all by-products. Further, there were listed the contents of fertilizer substances (nitrogen, phosphoric acid, potash) in 40 types of by-products from agricultural areas. The average contents of nitrogen, phosphoric acid, and potash in agricultural by-products were 1.43%, 0.59%, and 1.90%, respectively. As a result of estimating the annual nitrogen supply amount from 26 agricultural by-products in 2018, it was found that it could supply 44,911 tons of nitrogen. The investigated by-products contained fertilizer substances such as nitrogen, phosphoric acid, and potash, but the contents were lower compared to castor oil-cake used as main component of organic fertilizer. Therefore, resource management plan needs to be established for efficient use of by-products because time, location, and nutrient content of agricultural by-product production were extremely different. Research on fertilizer and manure using agricultural by-products need to be conducted to develop and distribute alternatives for imported oil-cakes.