• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.2
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• pp.98-107
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• 1983

This experiment was carried out to determine the optimum fertilizer level of N-P-K for maximum yield of grasses at hill-land pasture. The pasture species tested were orchardgrass, tall fescue, alfalfa and ladino clover. The results are summarized as follows: 1. The difference in yield of treatment 1, 2, and 4, 5 was significant at the 5% level. In other word, alfalfa yields from 6-30-30 kg/10a and 6-40-30 kg/10a (N-P-K) application were significantly increased over the yields from 4-20-20 kg/10a and 4-30-20 kg/10a (N-P-K). In observing the yield from the treatment 5 where 10 kilograms of phosphate was additionally applied over the treatment 4, it was increased in yield but failed to show statistical significance. With these results, the most optimum rates of N-P-K for alfalfa production are 6-30-30 kg/10a. 2. Ladino clover showed the highest yield at treatment 6 with statistic significance at the 1 percent level over the other treatments. Therefore, NPK rates of 6-30-40 kg/10a would be the most optimal rates for maximum production of ladino clover. 3. Orchard grass yield showed significance at the 1 percent level among other treatments except treatment 3 and 4. The highest yield was also shown at treatment 6 where NPK rates applied 40-30-40 kg/10a. 4. Tall fescue yield showed high significance at the 1 percent except treatments between 2 and 3, 5 and 6. The highest yield was observed at treatment 6 where NPK was applied 40-30-40 kilograms per 10a. 5. Nitrogen content of dry matter was 0.91-1.05% in 20 kg of N and 1.05-1.26% in 30-40 kg of N per 10a. The absorption rate of nitrogen applied was 23-31% regardless of the nitrogen level. Potash content of dry matter was increased in accordance with increasing K rates. 6. The gross income was the highest on the N-P-K application of 4-20-30 kg/10a in alfalfa and ladion clover, 40-30-40 kg/10a in orchardgrass and 30-20-20 kg/10a in tall fescus.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.1
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• pp.5-11
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• 2024

Objective of this study was to evaluate the effect of organic fertilizer application on yield, soil chemical properties and soil organic carbon (SOC) in Korean cabbage cultural field. The experimental treatments consisted of none fertilizer (NF), NPK (inorganic fertilizer, N-P₂O₅-K₂O : 320-78-198 kg ha^-1), Organic fertilizer (OF 50, 100, 150% on application rate of standard 110 kg ha^-1 as N, topdressing: 210 kg ha^-1 as inorganic fertilizer). In experimental results, the growth characteristics and yields were not significantly different among the treatments. There was no significant difference in soil pH, available phosphate, ammonium nitrogen and exchangeable potassium, while organic matter, electrical conductivity and nitrate nitrogen were increased when organic fertilizer application. Also, SOC was increased with the application of organic fertilizers. These results showed that pre-application of organic fertilizer might be effective in a carbon storage in the field soil cultivating Korean cabbage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.491-496
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• 2006

The present study was initiated to explore the yield potential of bushbean by exploiting the interaction of variety, sowing time, and fertilizers containing N, P, and K Two varieties namely BARI Bushbean 1 and BARI Bushbean 2, three levels of fertilizer viz. control ($N_{0}P_{0}K_{0}$), medium ($N_{20}P_{30}K_{30}$), high ($N_{40}P_{60}K_{60}$) and three sowing times (November 15, December 1 and December 15) were considered as treatment variables. Among the varieties, BARI Bushbean 2 always showed better performance for most of the yield and yield attributes duly attributed by the application of fertilizers ${\circleda}$ N: P: K = 40: 60: 60 respectively. The highest seed yield (1375.17 kg/ha) was recorded when the crop was sown on the $15^{th}$ November with the supplemented soil nutrition status as above. The influence of sowing times indicate that there is a gradual trend of decreasing in seed yield and other associated parameters after first sowing ($15^{th}\;November$). The results of this study suggest that the multi-locational trial under varied sowing times with soil nutrition might potentially increase the long-term adaptation of bushbean in Bangladesh.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.4
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• pp.287-292
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• 1990

A study has been conducted since 1954 to elucidate the effects of longterm application of ammonium sulfate (AS), urea, compost, and calcium silicate(CS) fertilizers on major soil nutrients and rice yields in wetland soil. The soil pH in the AS plot become lower than that in the urea plot but had little influence on rice yield. Continuous application of AS and urea with compost and CS raised the soil pH compared with single applications of AS or urea. Soil organic matter content increased yearly in plot with no fertilizer and in those with AS and urea, and increased considerably in plots with compost and CS. Application of compost and CS promoted rice top growth as well as root growth, resulting in increased dry matter. Soil contents of N, $P_2O_5$, Ca, Mg, and $SiO_2$ in the NPK with composts plot increased considerably compared with the NPK plot; however. the exchangeable K content was rather low. Rice growth increased with compost application. which enhanced K uptake, and the coarse texture promoted K leaching. With compost and CS addition, con tents of exchangeable Ca and Mg in the AS plot decreased considerably more than in the urea plot. Probably this was the result of higher Ca and Mg precipitation by sulfate in the AS plot. The re are no significant differences in rice yield between AS and urea plots. With compost and CS treatments, rice yields increased in the AS plot compared with the urea plot. The increase in yield is considered to be the effect of S. which is a constituent of AS.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.2
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• pp.117-124
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• 2012

This study was conducted to estimate Hanwoo carrying capacity when whole crop barley or rye as winter forage crops was grown on different applying sources (chemical fertilizer, cattle or organic fertilizer) and mixed sowing combination with hairy vetch or forage pea during the period of 2008~2010. The experimental plots within whole crop barley or rye were consisted of 7 treatments, which were non-fertilizer, chemical fertilizer (P+K), chemical fertilizer (N+P+K), organic fertilizer, cattle slurry, cattle slurry with hairy vetch, and cattle slurry with forage pea. Each plot was triplicates and experimental treatments were allocated in the randomized complete block design. For whole crop barley, annual mean dry matter (DM) and total digestible nutrients (TDN) yields were the highest in N+P+K plots, but there were no significant differences among organic fertilizer, cattle slurry and mixed sowing with legumes. The TDN and RFV were the highest in mixed sowing plots of forage pea plus cattle slurry application. As 450 kg Hanwoo heifers were fed diets included 70% whole crop barley, organic fertilizer, cattle slurry application and mixed sowing with legumes plots is capable of raising average 2.5 to 2.9 heads/ha a year. For whole crop rye, annual DM, crude protein, and TDN yields of application groups and mixed sowing treatment with legumes showed 6.69~7.13, 0.46~0.51 and 3.95~4.18 ton/ha, respectively. In case of 450 kg Hanwoo heifers fed diets included 70% forage rye, it is estimated that cattle slurry application (mixed sowing with legumes) plots can rear average 3.1~3.3 heads/ha a year. It can be concluded that, on the basis of DM yield, not only mixed sowing with legumes by applying cattle slurry rather than single sowing of whole crop barley or whole crop rye enhanced production yield and feed values, but also it could be a substitute for imported grains as dietary protein sources in the case of feeding Hanwoo.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.454-459
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• 2007

This experiment was conducted to investigate the effect of long-term continuous application of fertilizers for rice cultivation from 1954 to 2003. Changes of physical and chemical properties of paddy soil and the rice yield by continuous application of fertilizers, particularly rice straw compost, over fifty years were discussed in this paper. The rice yields of compost applied plots were 5~12% higher while those of no fertilizer plots were 21~38% lower compared to those of NPK fertilizers applied plots. Uptakes of T-N, $P_2O_5$, $K_2O$, CaO, MgO, and $SiO_2$ by rice plants were significantly increased by the application of straw compost. Bulk density, hardness, and liquid phase of soil in compost applied plots were significantly decreased while gaseous phase and cation exchange capacity (CEC) of soil were increased compare to those in NPK plots. When the bulk density of soil was increased the rice yield was decreased. The soil organic matter (SOM) content tended to increase in compost applied plots whereas no significant differences were found in other treatments. The soil organic matter content increased by $0.4g\;kg^{-1}\;yr^{-1}$ when $7.5Mg\;ha^{-1}\;yr^{-1}$ of rice straw compost applied in paddy land. The compost application rate recommendation for rice cultivation in Korea could be revised by the results of this study.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.93-97
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• 2012

This study was conducted to evaluate the efficiency of various inorganic and organic materials to improve physical properties of soil. Saline sodic soil (saturation percentage = 40.36%, $EC_e=5.15dS\;m^{-1}$, $pH_s=8.70$, $SAR=18.84(m\;mol\;L^{-1})^{1/2}$, bulk density =$1.49Mg\;m^{-3}$) was collected, brought to wire house and filled in pots after laboratory analysis for various parameters. Different sources of organic nutrients like farm manure (FM), press mud, compost, poultry manure and sesbania green manure were analyzed for their chemical composition. The experiment comprised of 12 treatments replicated thrice; $T_1$: control (recommended NPK), $T_2:{\frac{1}{2}}$ recommended NPK, $T_3$: FM at 1.5% by soil weight, $T_4$: pressmud at 1.5% by soil weight, $T_5$: compost at 1.5% by soil weight, $T_6$: poultry manure at 1.5% by soil weight, $T_7$: sesbania green manure at 1.5% by soil weight, $T_8:T_2$ + FM at 0.75% by soil weight, $T_9:T_2$ + pressmud at 0.75% by soil weight, $T_{10}:T_2$ + compost at 0.75% by soil weight, $T_{11}:T_2$ + poultry manure at 0.75% by soil weight, $T_{12}:T_2$ + sesbania green manure at 0.75% by soil weight. These treatments were applied using completely randomized (CR) design and appropriate time was given to decompose these organic nutritional sources. Seeds of wheat cultivar Sahar-2006 were sown. After harvesting the wheat, soil samples were collected from each pot and analyzed for various physical properties like bulk density, porosity and saturation percentage. An improvement in physical properties (bulk density, porosity and saturation percentage) of soil was noticed with the application of various organic nutritional sources but role of compost alone ($T_5$) remained prominent.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.301-304
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• 1983

Effects of the clay content on soil chemical properties and rice productivity were studied to evaluate the optimum range of clay content from 42 NPK trials conducted by the provincial ORD in 1979. Nutrients content and CEC of the paddy soils were increased with the increase of clay content in paddy soils. Rice yields without NPK application showed a positive linear regression with respect to surface clay content in the paddies, while the relationship between rice yield and clay content with optimun fertilization showed a curvilinear regression, which indicated the maximum yield was observed in loam soils. However, the yield of rice was not significantly different in the range of clay content from 14 to 38%. It implies that the clay content more than 15% may be secondary constraint in determining the soil productivity.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.44-49
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• 2008

Sufficient inorganic nitrogen supply for crop growth is crucial for economically sustainable organic farming. The effects of an application of cover crop biomass on crop growth, nitrogen utilization and carbohydrate composition were investigated during early stage. Short-term changes in soil nitrogen after incorporating fresh hairy vetch and rye shoots were measured. The inorganic nitrogen from cover crops reached the peak at 15 ($NH_4-N$) and 24 ($NO_3-N$) days after incorporation, and then decreased rapidly. The highest concentration of soil nitrate showed at 27 days of incorporation in hairy vetch and at 18 days in rye, and three fold differences exhibited between two treatments. Crop growth under hairy vetch or rye incorporation significantly differed. At 20 DAT, dry matter production in NPK and hairy vetch was about two fold greater than that in rye. Difference in decomposing rates of hairy vetch and rye had also influence on nitrogen status in leaves and roots of pepper plants. Total nitrogen was greater in NPK and hairy vetch than in rye until 20 DAT, whereas inorganic nitrogen (nitrate and nitrite) concentration was higher in rye. Temporal changes in soluble sugars and starch in pepper plants among treatments were similar, although difference in the amount existed. It was suggested that hairy vetch as an alternative nitrogen source promoted crop growth and mineral utilization during early growth stage, whereas an obvious effect in rye was not found.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.305-312
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• 2017

We aimed at investigating the difference in $N_2O$ emission factors of chemical and organic fertilizers and identifying the main factors influencing annual fluctuations in $N_2O$ emission. We conducted two-year experiments in 2016 and 2017 in an agricultural field planted with sweet potato (Ipomoea batatas). Treatments included chemical NPK fertilizer (NPK) and chicken compost application at $10\;ton\;ha^{-1}$, $20\;ton\;ha^{-1}$, and $30\;ton\;ha^{-1}$ rates (CK1, CK2 and CK3). Control was also employed with no addition. Results showed that $N_2O$ emission rates were significantly related with soil water status and soil available N contents. Significant correlation between % water filled pore space (WFPS) and $N_2O$ emission was observed only when the %WFPS was greater than 40% and during the initial stage of the experiment (<60 d). Comparison of the emission factors in 2016 and 2017 showed us that the emission factor was greater in 2016 when the %WFPS was maintained higher by 16.5% compared to that in 2017. In 2016, the emission factor of organic fertilizer was higher than that of chemical fertilizer, while in 2017, the pattern was reversed. Annual variability in $N_2O$ emission could also be originated from the available N contents remaining in soil after being taken up by plants. If we apply excessive N fertilizer, the soil would contain excess amount of N which was not uptaken by plants, leading to a huge increase in $N_2O$ emission. This case would overestimate emission factor, which was the case for the organic fertilizer in 2016. Over-fertilization should be avoided when we set up an experiment to determine $N_2O$ emission factor.