• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.55-61
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• 1987

A series of laboratory experiments were carried out to find the effects of soil organic matter contents, soil temperature, pH values, kinds and amount of nitrogen fertilizers on the denitrification-$N_2O$ gas evolution-. The results obtained were summarized as follows: 1. Denitrification rate, amount of $N_2O$ gas evolution, was influenced the order of organic matter contents>soil temperature>pH values>kinds of N-fertilizer>levels of N-fertilizer. 2. The highest dentrification rate was observed in organic matter content of 3.0%, pH values at 6.0 with application of $KNO_3$ at levels of 20 mgN/100g soil. 3. For the evolution of I mole $N_2O$ gas, averaged carbon consumption was obtained as 0.5 mole in all these experiment condition. However, the highest carbon consumption rate was obtained in organic matter contents for 1.0% with application of $(NH_4)_2SO_4$ at levels of 10 mgN/100g soil (1.06 mole) while lowest carbon consumption rate was obtained in organic matter contents for 3.0% with application of $KNO_3$ at levels of 20 mgN/100g soil (0.13 mole). 4. According to Michaelis-Menten's equation, the V/2 values for evolution of $N_2O$ gas was estimated by progress curve. The results obtained was as 550 ug for $(NH_2)_2CO$ and 1100 ug $N_2O/100g$ soil by application of $KNO_3$ in organic matter contents of 1.0% soil. On the other hand, when the application $(NH_4)_2SO_4$ the V/2 values of $N_2O$ gas was obtained as the amount of 490 ug/100g soil while V/2 values of $N_2O$ gas by application of $KNO_3$ was on the linear line in soil organic matter contents of 3.0%.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.70-73
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• 1993

This experiment was carried out to investigate the effect of planting density on thegrowth and yield of Rehmannia glutinosa. A local variety was planted on the 100cm row, with different planting density of 20, 30 and 40 plants per $m^2$. Nitrogen, phosporus and potassium fertilizers were applied as 12, 12, and 16 kg /10a, respectively with compost of 1,000kg /10a. Plant height became shorter with increase in the planting density from 20 to 40 $plants\;/\;m^2$. But emergence date, leaf length and width were not significantly changed with planting density. As the planting density was increased, tuber diameter got slender and tuber number was decreased, but tuber length was not affected. The tuber yield was 793kg /10a at the planting density of 20 $plants\;/\;m^2$ and it increased 40% at 30 $plants\;/\;m^2$ and 45% at 40 $plants\;/\;m^2$ Regarding on the farmer's income, optimum planting density was estimated 30 $plants\;/\;m^2$.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.153-159
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• 2010

Nowadays, Korean farmers rely more on chemical fertilizers than low input sustainable agriculture drawn from the farm itself. In order to improve soil nutritional imbalance for environment friendly agriculture in greenhouse, we have carried out a relationship between fertilizer application level, and soil chemical properties for strawberry cultivation at 56 sites in Chungnam Province. Average amount of nitrogen as basal fertilization was 92.3 Mg $ha^{-1}$ which higher 2.6 times compared to standard amount of basal fertilizer. In case of compost application more than 30 Mg $ha^{-1}$, excessive ratio compared to optimum level was higher 1.8 times for EC value, 3.0 times for available phosphate, 2.6 times for exchangeable potassium, 1.7 times for exchangeable calcium, and 1.6 times for exchangeable magnesium, respectively. Amounts of compost application significantly correlated with available phosphate (r=0.370, $p{\leq}0.01$), exchangeable potassium(r=0.429, $p{\leq}0.01$), exchangeable calcium(r=0.404, $p{\leq}0.01$), exchangeable magnesium(r=0.453, $p{\leq}0.01$), and exchangeable sodium(r=0.369, $p{\leq}0.01$), respectively. Our results suggest that soil nutrients management for sustainable agriculture was optimum fertilization based on soil testing for strawberry cultivation in greenhouse.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.140-145
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• 1995

This experiment was carried out to investigate the effect of plant spacing on the growth and root yield at different harvesting year in Astragalus membranceus. A local variety collected in Jung Sun. Kang Won was used on the 30 and 40cm row spacing, with different spacing between plant of 5, 10, 15, 20cm respectively. Nitrogen, phosphorus and potassium fertilizers were applied as 6, 8 and 9kg/10a respectively, with compost of 1,000kg/10a. Branches, root length, root diameter and root weight were increased in the sparse planting compared with the dense planting. But emergence date, flowering date, stem height and node number were not significantly changed with plant spacing. The highest root yield was 211.8kg/10a at the $30{\time}10cm(67\;plants/m^2)$ in 1 year old plants of Astragalus membranceus. In case of two years old plants, branches, node number, root length, root diameter and root weight were increased in the sparse planting compared to the dense planting. But harvesting ratio was decreased in the dense planting, The highest dried root yield was 292kg/10a at the $40{\time}10cm\;(25\;Plants/m^2)$. In case of 3 years old plants, aerial part and root growth pattern were similar to the 2 years old plants, The dried root yield was highest(623kg/10a) in the $40{\time}10cm(25plants/m^2)$.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.145-151
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• 1976

This study was conducted to determine the effect of slaked lime and straw used on the soil pH in the flooded condition and yield of rice grown in AKIOCHI paddy field and their residual effects on the rice plants. The results obtained were summarized as follow: when lime and straw were applied, there was on the average 41% of yield increase over plots treated with three elements of chemical fertilizers. When lime plus straw were used, the growth rate at later stage of rice plant was prominent. Damage due to helminthosporium and blast were found less, the rate of lower-leaf death was low, and grain number, per head, filled grain ratio, and weight of rice grain were higher than control. When lime plus straw were used, higher amount of silicate, calcium, nitrogen and potassium was found in the plants at heading stage. The residual effects of lime plus straw were 20% in the first year, about 10% in the second year and 5% in the third year, respectively. Soil pH was affected by both straw and slaked lime, and it was fixed about 8 days after applying in the flooded condition. The following formulae was suggested from the results in the flooded conditions. $$pH=5.5293+8.6007X_1+2.7836X_2-{6.7422X_1}^2-{1.8522X_2}^2-7.000X_1X_2$$ ($X_1$=slaked lime, $X_2$=straw)

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.185-198
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• 2011

This study was carried out to select a proper forage crop, and to estimate the proper level of application of cattle manure and carrying capacity of organic livestock per unit area. Corns and forage sorghum hybrids were cultivated with different types of livestock manures and different amount of them to produce organic forage. For both corns and forage sorghum hybrids, no fertilizer plots had significantly (p<0.05) lower annual dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) yields than those of other plots, whereas the N-P-K (nitrogen-phosphorous-kalium) plots ranked the highest yields, followed by 150% cattle manure plots and 100% cattle manure plots. DM, CP and TDN yields of in cattle manure plots were significantly (p<0.05) higher than those of no fertilizer and P-K (phosphorous-kalium) plots. The yields of in cattle slurry plots tended to be a little higher than those of in composted cattle manure plots. Assuming that corn and forage sorghum hybrids produced from this trial were fed at 70% level to 450kg of Hanwoo heifer for 400g of average daily gain, the carrying capacity (head/year/ha) of livestock ranked the highest in 150% cattle slurry plots (mean 6.0 heads), followed by 100% cattle slurry plots (mean 5.3 heads), 150% composted cattle manure plots (mean 4.7 heads), 100% composted cattle manure plots (mean 4.4 heads), and no fertilizer plots (mean 2.8 heads) in corns (or the cultivation of corns). Meanwhile, in the case of forage sorghum hybrids, 150% cattle slurry plots (mean 6.4 heads) ranked the highest carrying capacity, followed by 150% composted cattle manure plots (mean 4.8 heads), 100% cattle slurry plots (mean 4.4 heads), 100% composted cattle manure plots (mean 4.1 heads), and no fertilizer plots (mean 2.8 heads). The results indicated that the application of livestock manure to cultivated soil could enhance not only DM and TDN yields, but also the carrying capacity of organic livestock as compared with the effect of chemical fertilizers. In conclusion, the production of organic forage with reutilized livestock manure will facilitate the reduction of environmental pollution and the production of environmentally friendly agricultural products by resource circulating system.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.102-108
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• 2006

It is very important to improve fertilizer use efficiency for the saving of fertilizers and for environmental purposes as well. However, there was no effective ways for the fertilization in the mid of growth under the plastic film mulching cultivation so far. For this, a Band Spotty Fertilization (BSF) machine was developed recently. So, we tried to establish a low input fertilization technique using this BSF machine in the vinyl mulching cultivation of onion (Allium cepa L.). Fertilization efficiency, soil properties, and crop yield were examined and compared among treatments from 2000 to 2001. The content of exchangeable K in soils were higher after fertilization but that of available $P_2O_5$ was lower than before the experiment in all plots. The content of nitrate-N was highest at the early growth stage, and higher in BSF plots than that of conventional fertilization (CF). BSF plot showed higher growth rate, and uptake amount of nitrogen of onion by 59-69% than that of CF. N use efficiency in BSF was higher in the order of two time-split application, one time-split application, and three time application. K use efficiency was high 13-17% BSF plots than that in CF($63kg\;ha^{-1}$) plots. The amount of residual N in soils was high by 8-14% in BSF plots compared to that in CF plots, and the loss of N was lowered 26-34% by BSF. Also, the amount of residual K in soils was high by 13-18% and the loss of K was low by 29-31% in BSF plots compared to that in CF plots. The yield of onions increased by 7-13% by BSF due to increased diameter and weight of bulbs. As the results, N fertilization efficiency increased by 22-42% by BSF.

• Journal of Korean Society of Forest Science
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• v.81 no.1
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• pp.53-65
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• 1992

For elucidating effective methods of restoration of forest recreational sites where management goals are maintaining naturalness and conserving natural ecosystem, seeding, fertilization and soil surface treatment were used for four years at the devastated forest-floor. For restoration of forest-floor vegetation, factorial experiment was used with a split plot design(main plot : fertilization, subplot : soil surface${\times}$seeding) and a randomized complete block design (fertilization${\times}$seeding) at the Kwanaksan Aboretum, Anyang, Kyonggido. Results were summarized as follows : Soil surface softening with tipping and ripping and straw-mat mulching (70% coverage) treatment was effective on germination, survival and growth of seeded vegetation at devastated forest-floor. Especially, straw-mat mulching treatment was effective on soil surface stabilization and seedling's survival at eroded soil surface, while complete soil surface softening treatment was effective on germination, survival and early growth of tree species of late-successional series. Introducing seeds of native species of pioneer or early-successional series, with good growth capability in barren soil was effective on rapid restoration in devastated forest-floor with its soil surface previously compacted and its surviving seeds washed away. When the seeding and straw-mat mulching after partial soil surface softening with tipping and ripping treatment were employed, it took about three years to restore the devastated forest-floor where surface erosion had been undertaken for an extended period of time and where naturally surviving seeds of native species had been washed away. Softening treatment of soil surface was effective for about two years, and seeding and soil surface treatment increased number of seedlings and improved soil surface environment through fixing of movement of the fallen leaves. Fertilizing effect was not oberserved, mainly due to seeding exposure and poor physical condition including soil surface erosion, low soil water potential and drought, etc, at the field experimental site. However, application of nitrogen and phosphate fertilizers was effective on seedling survival of the species in late-successional series, while lime application adversely affected the seedling survival.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.251-258
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• 2005

This study was conducted to examine the effect of application of pig manure slurry(PMS) for rye cultivation in Paddy-land on rice productivity The field experiments were carried out from 1999 to 2002 on well-grown rice in Paddy-land at Kimje, Chunbuk province in Korea. PMS was manufactured by the fermentation for 6 months in natural condition. Amount of PMS was adjusted equal to total nitrogen value relative to its value of commercial chemical fertilizers. The amount of PMS were spread evenly over the soil surface two times; first in the autumn (before sowing, end of November) and second in the spring(regrowth of rye, middle of March). The field plots were consisted of four kinds (PMS $100\%$ treatment, PMS $200\%$ treatment PMS $100\%$ treatment with half of CF (CF $50\%$), Full of CF treatment (CF $100\%$). The experiment was designed as a randomized complete block. Each treatment was replicated three times. Rices are customarily gown under tropical korean condition as annuals. The results obtained from this study were summarized as fellows. Panicle length of rice was shorter in PMS $100\%$ than other treatments. Ripening grain ratio was the lower in CF treatment. In treatment of PMS $100\%$ and PMS $200\%$, 1000 grain weight was a downward trend as compared to that of full of CF treatments, whereas number of grains per $m^2$ was increased as compared to other treatments. Number of panicles reveals that there is an increase in order; CF $50\% + PMS\;100\%>\;PMS\;100\%\;>\;CF\;100\%\;>\;PMS\;200\%$. Yield of milled rice showed hi인 in CF $100\%$ and $CF 50\%+ PMS 100\%$, but were was no significant difference among treatments. There were did not a regular tendency in the ratio of leaf sheath bright, however the ratio of lodging area was higher in $CF50\%+PMS\;100\%$ treatment than other treatments. Based on the results of this experiment, $CF 50\%+PMS\;100\%$ may be the most effective in rice productivity under application of PMS for rye cultivation in Paddy-land.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.51-62
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• 2009

This study was carried out development a new composting system to lower copper and zinc concentration in plg sludge compost and conduct an inquiry into the possibility of crop cultivation. The concentrations of nitrogen, phosphorus and pH averaged 4.4%, 6.3% and 7.57, respectively, which were higher concentrations than in commercial organic fertilizers, and the concentrations of copper and zinc averaged 805 and 1,704 mg/kg, respectively, which were beyond the heavy metal concentration limit in byproduct compost. Hydrated citric acid I lowered the concentrations of copper and zinc by 58% and 97%, respectively and hydrated oxalic acid II lowered the concentrations of copper and zinc by 48% and 56%, respectively in pig sludge compost. Lower concentrations of copper and zinc in pig sludge resulted from the enhanced hydrated-citric acid concentration in organic acid solution mixed with distilled water. The concentrations of copper and zinc were 330, and 41 mg/kg in the pig sludge treated with 100% hydrated citric acid. Agitation composting system stabilized the compost earlier than the stationary composting system, in which the stabilization condition was confirmed by higher temperature by $4^{\circ}C$ at highest temperature and 7 days earlier cooling down after highest temperature. The levels of germination index (G.I) 80 were obtained 15 and 20 days after composting in agitation and stationary composting system, respectively. The concentrations of copper and zinc were 2.4 and 4.26 mg/kg respectively in soils amended with pig sludge compost after removing process of heavy metals by citric acid, but 8.0 and 22.37 mg/kg, respectively in soils amended with Pig Sludge. The concentrations of heavy metals was highest in com cultivated in soils amended with pig sludge. The copper and zinc concentrations In corn leaves were 75.2 and 50.56 mg/kg respectively, which were 4 and 2 fold higher than the com cultivated in soils amended with pig sludge compost after heavy metal removing process by hydrated citric acid.