• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.244-251
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• 1991

This study was undertaken to assess the effectiveness of magnesium-and boron-enriched complex fertilizer(CF, N-P$_2$O$_{5}$-K$_2$O-MgO-B$_2$O$_3$: 14-10-12-3-0.2) on the maintenance and management of hilly pasture. The effectiveness of CF was compared to those of some straight fertilizers (SF). This first part of the study was concerned with the soil chemical properties and the mutural balances of mineral nutrients in the soils of a mixed grass-clover and a pure grass swards. The results of a two-year field experiment are summarized as follows: 1. The Mg contents in the soils of the CF plots were higher than those of the SF plots. On the other hand, the Ca contents were higher in the SF plots than in the CF plots. The contents of Mg and Ca, and CEC, except K, in both the CF and SF plots were considerably below the optimum levels. At the normal application rate of NPK, the contents of available P$_2$O$_{5}$ were close to the optimum level in both the CF and SF plots. 2. The contents of exchangeable Mg were lower than the K contents in soils of all the plots. At the normal application rate of NPK, the Mg contents in the CF plots, but not in the SF plots, were close to the critical level for general crops (0.29me Mg/100g soil). The Mg contents in soils of all the plots, however, were considerably below the critical level for pasture forages and grazing cows (0.41me/100g). 3. Considering the desirable base saturation level of soil, the saturation levels of Ca and Mg were insufficient in both the CF and SF plots. The saturation levels of Mg in the CF plots, however, were relatively good compared with the SF plots. The equivalent ratios or Mg/K, Ca/Mg. Ca:Mg:K, and %Mg of CEC in soils were generally unfavorable in all the plots. These ratios of the CF plots, however, were relatively better than those of the SF plots. 4. Considering the contents of exchangeable Ca and Mg in soils, it is suggested that the application of slaked magnesium lime as a soil amelioration might be desirable for the fundamental increment of those contents at pasture establishment.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.283-288
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• 2010

This study were carried out to evaluate effect of consequent application of pig manure compost (PMC) on soil chemical properties, dehydrogenase activity, and yield of potato in volcanic ash soil. The more application rate of PMC increased, the more increased soil pH, total-nitrogen, available phosphate, exchangeable cations (K, Ca, and Mg), heavymetal (Zn and Cu)contents. When application rate of PMC and crop cultivation times increased gradually, soil dehydrogenase activity was significantly increased. After third cultivation period, dehydrogenase activity showed PMC 2 ton (3.5), PMC 4 ton (6.3), PMC 6 ton (8.0 ug TPF $g^{-1}\;24h^{-1}$), respectively. The activity was twofold higher than first cultivation period. During the third cultivation period, dehydrogenase activity increased linearly comparison to Cu and Zn contents and that was correlated with Cu ($R^2$=0.907) and Zn ($R^2$=0.859) content, respectively. As the application rate of PMC increased, the yield of potato increased, but NPK+PMC 2 ton treatment was more higher than other treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.292-297
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• 2007

Global warming and climate changes have been major issues for decades andvarious researches have reported their impact on our environment. According to recent researches, increased carbon dioxide ($CO_2$) concentration in the atmosphere is considered as a dominant contributor to global climate changes and thus numerous researches were conducted to control $CO_2$ concentration in the atmosphere. Soil management practices, such as reducing tillage intensity, returning plant residues, and enhancing cropping system have recommended for restoring organic carbon into the soils effectively. However, few studies on soil carbon sequestration have reported for Korean paddy soils. Therefore, evaluation of soil organic carbon (SOC) dynamics in the long-term single rice cropping system is essential in order to find out potential capacity of paddy field as a carbon sink source. The objective of this research was to evaluate SOC dynamics on the long-term single rice cropping system. Research was conducted in the research farm at National Institute of Agricultural Science and Technology, Rural Development Administration, Suwon. Long-term phosphorus and potassium fertilization and lime application didn't significantly affect on SOC compared to controls. We found that SOC contents were increased continually at the long-term composting plots with enhanced rate of carbon storage. In conclusion, continuous incorporation of plant residues (i.e., composting) is recommended to effectively sequester soil carbon for Korean paddy soils. This result implies that continuous composting in a paddy field may contributenot only for increasing SOC in the soils but also for mitigating global warming through reducing carbon dioxide emission into atmosphere. Therefore, we recommend that a strategy or policy measures to encourage farmers to return plant residues continuously for mitigation of global warming as well as soil fertility is being developed.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.372-380
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• 2002

This study was conducted to investigate the changes of soil properties for potato and Chinese cabbage after application adding phosphorus and potassium fertilizers in the mounded highland soil from 1999 to 2001. Experimental plots were designed with control(NPK+Lime+Compost) and chemical improvement(Control+Application adding P and K). Mounded soil before field experiment of first year(1999) was low in organic matter, available phosphorus and exchangeable potassium, and the soil texture was loamy sand soil. After 3 years, the contents of soil organic matter increased a little, and available phosphorus and exchangeable potassium contents were remarkably increased. The crop growth in chemical improvement plot was better than control plot. Yield of chemical improvement plot in comparison with control plot was increased by 5~22% for potato and 6~25% for Chinese cabbage after 2~3 years.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.880-885
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• 2010

Importance of climate change and its impact on agriculture and environment has increased with a rise of greenhouse gases (GHGs) concentration in Earth's atmosphere. Nitrous oxide ($N_2O$) emission in upland fields were assessed in terms of emissions and their control at the experimental plots of National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA) located in Suwon city. It was evaluated $N_2O$ emissions at different soil water content, soil temperature, and mineral N conditions in a upland cultivating red pepper and soy bean. The results were as follows: 1) There were significant correlation between amount of $N_2O$ emissions and soil temperature, soil water content and mineral N conditions showed $0.528^{**}$, $0.790^{***}$ and $0.937^{***}$ in red pepper field and $0.658^{***}$, $0.710^{***}$ and $0.865^{***}$ in soybean field, respectively. 2) From the contribution rate analysis as to contribution factors for $N_2O$ emission, it appeared that contribution rate was in the order of mineral N (71.9%), soil moisture content (23.6%), and soil temperature (4.5%) in pepper field and mineral N (65.5%), soil moisture contents (19.2%), and soil temperature (15.2%) in soybean field.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.103-110
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• 1993

This study was made to evaluate the chemical properties of 481 farmers' orchard fields in An-Seong area. And the reasonable ferilizer rates were recommended utilizing the result of soil analysis. The results are summarized as follows : 1. As the soil fertility status of collected soil samples were evaluated on the basis of temporary optimal range for each soil chemical properties, 12.7 to 49.6% of the total 481 farmers' fields were range for soil improvement. 2. The contents of chemical component have a tendancy to decrease with depth gradually from surface to subsoil. 3. According to the relationship between the contents of soil component in subsoil and those in surface soil, the fertility condition of subsoil could be estimated on the basis of analysis data of surface soil. 4. The multiple regression equation for pear yield prediction to the organic matter and exchangable calcium contents in the soil were obtained. 5. Referring the average value, distribution ratio compared to the optimum level for each soil chemical properties and standard fertilizer rate, the soil fertility status could be categorized as "High" "Medium" and "Low". For each category, the recommended amounts for NPK and organic matter application were established. 6. The recommended rates through soul fertility diagnosis were less than farmer's dosage in the range 7.1~7.7 kg/10a for N, 0.8~11.5 kg/10a for $P_2O_5$, 7.1~19.9 kg/10a for $K_2O$ and 90~116 kg/10a for lime.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.744-748
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• 2012

This study was carried out to investigate the incorporation effect of green manure crops (GMC) such as the hairy vetch on improvement of soil environment in reclaimed land during sorghum${\times}$sudangrass hybrid (SSH) cultivation over the past three years from 2009 to 2011. Plots consisted of conventional fertilization (CF) and incorporation of GMC were divided by rates of additional nitrogen fertilizer ($100kg\;ha^{-1}$) and decreased percentage of 30 50 70 100 fertilization in addition to non nitrogen fertilization (NNF). Soil physico-chemical properties, growth and yield potential were examined. The results were as follows. The testing soil was showed strong alkaline saline soil with low organic matter contents and less available phosphate while exchangeable sodium and magnesium were higher. Soil salinity was increased during cultivation of summer crop. However, SSH was not affected by salt content. The fresh weight of GMC at incorporation time was $18,345kg\;ha^{-1}$. Content of total nitrogen at incorporation time was 3.09% and the C/N ratio was 12.8. Fresh and dry matter yield of SSH were higher in the order of 30%, CF, N50%, N70%d, N100%, and NNF. Fresh and dry matter yield of SSH increased in the order of CF ($55,050kg\;ha^{-1}$, $16,250kg\;ha^{-1}$), N contents from 30% to 9%. Soil physical properties, such as bulk density were decrease with incoporation of GMC, while porosity was increased. Soil chemical properties, such as pH was decreased while content of exchangeable calcium, available phosphate, and organic matter were increased. Also contents of exchangeable sodium and potassium were decreased with incorporation of GMC than those before experiment. Thus, we assumed that incorporation of hairy vetch was more effective that can lead to reduce chemical nitrogen fertilizer and to improve soil environment in cultivating SSH on Saemangeum reclaimed land.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.285-292
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• 2008

To investigate the effect of tillage methods on the silage barely growth and the soil environment in paddy field, liquid pig manure(LPM) was applied after harvesting rice at Jisan series soil for 2 years. Five plots, a LPM applied rate as N%; 0, 100, 150, 200(basal dressing) and 100(basal dressing)+50(additional fertilizer) were divided by tillage methods; non-tillage, non-tillage+rice straw and rotary tillage method. Emission amounts of $NH_3$ gas highly decreased in the rotary tillage and the non-tillage+rice straw plot compared to non-tillage plot. The contents of soil organic matter and exchangeable cation were increased in the applied LPM plot. $NH_4-N$ and $NO_3-N$ contents in soil were the highest in the non-tillage+rice straw plot and followed by the rotary tillage and highly decreased along with the growth of plant. Run-off rate of mineral components were higher in order of the rotary tillage plot£æthe non-tillage plot£æthe non-tillage+rice straw plot and then leached to $SO_4$, $NO_3-N$, K plentifully. The yield of silage barley in dry weight was higher in order of the non-tillage+rice straw plot>the rotary tillage plot>the non-tillage plot. To estimate the feed value of silage barley, crude protein, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were analyzed. Crude protein and ADF contents were the highest at rotary tillage N150% plot as 9.7 and 29.4%, respectively. NDF contents was the highest at non-tillage+rice straw N150% plot as 56.7%. In conclusion, we recommend not to incinerate rice straw and to apply LPM at non-tillage status in cultivating the silage barley. This may prevent water pollution and increase barley yields.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.89-93
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• 1973

In order to study the effects of some chemical components of surface soils on the paddy yield in clayey Whadong series developed on old alluvium, NPK fertilizer experiments conducted from 1966 to 1969 were reviewed and discussed, and the results may be summarized as follows. 1. The paddy rice production of Whadong series without fertilizers varied from 156kg to 719kg per 10a. 2. The paddy yields in Whadong series were associated mainly with the contents of organic matter and available phosphorus in surface soils, but not with those of exchangeable K, Ca, and Mg and cation exchange capacity. 3. The contents of organic matter in these soils more effected in the paddy yield than those of phosphorus did. 4. In case less than 2.0% or more than 3.0% of organic matter in surface soils the effect of phosphate application was appreciable. The effect, however, was not recognized from 2.0 to 2.9% of organic matter. And the following suggestions were able to make. a. In case of less than 2.0% of organic matter, the effect was considered to be due to deficiency of available phosphorus in the soil. b. In case of more than 3.0% of organic matter, the greater effect was considered to be due to inhibition of P uptake even in higher P contents in soil. c. Consequently, correlation study of P testing in paddy soil should be limited to the soils which contains less than 2% of organic matter. d. If the contents of organic matter in paddy soils were above 3.0%, the effect of P application was considerable and considered to be due to inhibition of nutrient uptake. Accordingly, it is considered that only the increased application of P does not improve the production of paddy in such soils.