• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.357-365
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• 2006

The investigations were conducted to find out the situation of fertilizer use and the contents of soil chemical components on summer vegetable crops at 791 farmers' upland fields located in the parts of Gangwon-do, Gyengsangbuk-do and Jeollabuk-do of alpine area. Major vegetable crops were potato, Chinese cabbage, radish, carrot, onion, and cabbage. From the location surroundings cultivated alpine vegetable crops, the orders were Gangwon-do>Gyeongsangbuk-do>Jeollabuk-do part in the sizes of a fie1d area and the height above sea level, and Jeollabuk-do>Gyeongsangbuk-do>Gangwon-do part in the slope degrees. The soil texture was of wide distribution on sandy loam soil for Gangwon-do(76%) and Jeollabuk-do part(64%), and 1oam(42%) and sandy loam soil(35%) for Gyeongsangbuk-do part. From the numbers of investigated fields, the distribution of slope degree was wider than those of height above sea level in relation to location surroundings. The upland soils of 785 fields cultivated vegetable crops were sampled at 0~15 cm of top soil before seeding or transplanting and analyzed. On an average, pH, organic matter, available phosphate and exchangeable potassium, calcium, magnesium of soil were 5.7, $27.6g\;kg^{-1}$, $765mg\;kg^{-1}$, $1.16cmol_c\;kg^{-1}$, $6.1cmol_c\;kg^{-1}$, and $1.6cmol_c\;kg^{-1}$, respectively. The average cation exchange capacity(CEC) of 120 sites in Gangwon-do part was $9.2cmol_c\;kg^{-1}$. The content of organic matter, exchangeable potassium, exchangeable calcium and exchangeable magnesium was higher, while that of available phosphate was lower with slope degrees. And the content of major chemical components in carrot soil was lower in comparison with other crop soils. The average levels of N, $P_2O_5$, $K_2O$, livestock manure and lime fertilizer of 785 Belds applied by farmers were 335, 198, 244, 12,680 and $1,750kg\;ha^{-1}$, respectively, for summer vegetable crops in alpine area. The average amounts of $N-P_2O_5-K_2O$ fertilizers applied by farmers in 785 Gelds of vegetable crops were higher 1.7~2.0-4.2~7.0-1.4~2.0 times on potato, 1.4~1.6-4.6~8.3-3.5~4.2 times on Chinese cabbage, and 1.2~1.3-4.2~7.2-3.0~3.61 times on radish than the rates of NPK fertilizers based on soil testing for each crop.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.485-491
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• 2011

The present study evaluated the soil microbial communities by fatty acid methyl ester (FAME) in upland soils at 25 sites in Gyeongnam Province. The total bacteria content was $143nmol\;g^{-1}$ for in inclined piedmont, $75nmol\;g^{-1}$ for fan and valley, $49nmol\;g^{-1}$ for hill areas, and $44nmol\;g^{-1}$ for riversider plain. The fungi content was 2.4 times higher in sandy loam than $21nmol\;g^{-1}$ in silt loam (p<0.01). In addition, inclined piedmont soils had a significantly higher ratio of monounsaturated fatty acids to saturated fatty acids compared with fan and valley soils (p<0.05). The communities of total bacteria and arbuscular mycorrhizal fungi in the inclined piedmont soils were significantly higher than those in the fan and valley soils and in the riversider plain soils (p<0.05), whereas the community of fungi was significantly lower (p<0.05). In principal component analyses of soil microbial communities, our findings showed that inclined piedmont was positive relationship with total bacteria and actinomycetes in upland soils.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.21-28
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• 2013

The objective of the study was to investigate the effect of rice straw mat, rice straw mat with PAM (Polyacrylamide) and gypsum addition on surface runoff and sediment discharge in field. Six experimental plots of $5{\times}22m$ in size and 3 % in slope prepared on gravelly sandy loam soil were treated with control, rice straw mat cover with gypsum and rice straw mat cover with gypsum and PAM. Radish in Spring and Chinese cabbage in autumn growing seasons were cultivated. Non point source (NPS) pollution discharge was monitored and compared among the treatments. Rainfall of the 10 monitored events ranged from 17.0 mm to 93.5 mm. Runoff coefficient of the events was 0.005~0.239 in control plot, 0~0.176 in rice straw plot with gypsum and 0~0.046 in rice straw mat plot with gypsum and PAM. When compared to the control plot, the runoff amount was reduced by 10.4~100 % (Ave. 60.8) in rice straw plot with gypsum and 80.7~100 % (Ave. 96.7 %) in rice straw mat plot with gypsum and PAM. The reduction of NPS pollution load was 54.6 % for BOD5, 71.5 % for SS, 41.6 % for TN and 61.4 % for T-P in rice straw with gypsum plot and 91.9 % for BOD5, 92.0 % for SS, 88.0 % for TN and 88.5 % for T-P in rice straw mat with gypsum and PAM plot. This research revealed that rice straw mat cover with soil amendments on the soil surface could not only increase the crop yield but also reduce the NPS pollution loads substantially.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.664-670
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• 2012

Experiments were conducted to find out the landscape effects and green manure production at the same time in farmland. Cornflower was grown in different soil texture with sand, sandy loam, loam, clay loam, and was sowing with autumn and spring respectively. The overwintering rate of cornflower was at 58.7% in average, and the treatment at sand soil showed 62.1% that was highest among other soils, which cornflower is possible to winter landscape crop. After flowering of cornflower, the contents of total nitrogen (T-N) and total carbon (T-C) in plant were 15.0 and $409.2g\;kg^{-1}$, respectively, and the carbon-nitrogen ratio (C/N) was 28.6. The yield of cornflower biomass, which will be returned to soil as green manure, recorded $1,210{\sim}3,920kg\;ha^{-1}$ at the spring seeding higher than the autumn seeding as $1,540{\sim}3,170kg\;ha^{-1}$, and the biomass treated by soil texture were showed that the treatments at the clay loam had been the largest yields both spring and autumn seeding among at other treatment of soil. The heights of cornflower regardless of soil treatments were 52.8 to 73.6 cm at the autumn seeding and 35.5 to 79.2 cm at the spring seeding although it was more significant variation at the soil textures than the seeding periods. The flowering periods of cornflower ranged from $17^{th}$ to $20^{th}$ in May at the autumn seeding and from $19^{th}$ to $20^{th}$ in June at the spring seeding, which was faster 30 days approximately at the autumn seeding than the spring seeding. In a view of the cornflower application as green manure after flowering, the autumn seeding, when considered to combine with following crops, was more suitable and various than the spring seeding, even though the yield at spring seeding was higher than one at autumn seeding.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.436-443
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• 2012

This research was focused on the effect of rice straw and rice straw mat on the reduction of upland field non-point source (NPS) pollution discharges. Six experimental plots of $5{\times}22m$ in size and 3% in slope prepared on gravelly sandy loam soil were treated with control, rice straw cover and rice straw mat cover. Radish in Spring growing seasons were cultivated. NPS pollution discharge was monitored and compared with respect to the treatments. The surface cover rate of rice straw and rice straw mat right after the treatments was 64.7% and 73.7%, respectively. Rainfall of the 16 monitored events ranged from 12.8 mm to 538.2 mm. Runoff coefficient of the events was 0.01~0.67 in control plot, 0~0.63 in rice straw plot and 0~0.45 in rice straw mat plot. The reduction of runoff compared to the control plot was 5.4~99.7% in rice straw plot and 32.9~100% in rice straw mat plot. The reduction of NPS pollution load was 52.0% for SS, 28.5% for T-N and 35.2% for T-P in rice straw plot and 79.8% for SS, 68.3% for T-N and 53.3% for T-P in rice straw mat plot. This research revealed that rice straw mat cover on the soil surface could not only increase the crop yield and farmer's income but also reduce the NPS pollution loads significantly.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.1-12
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• 2006

Changes in the soil physical property and the topographic condition derived from agricultural activities like as farming activities, land clearance and cutting down resulted in environmental and economic problems including the outflow of nutrient from farms and the water pollution. Several theories on the soil conservation have been developed and reviewed to protect soil erosion in the regions having a high risk of erosion. This study was done using the USLE model developed by Wischmeier and Smith (1978), and model for the slope length and steepness made by Desmet and Govers (1996), and Nearing (1997) to evaluate the potential of the soil erodibility. Therefore, several results were obtained as follows. First, factors affecting the soil erosion based on the USLE could be extracted to examine the erosion potential in farms. Soil erodibility (K), slope length (L), and slope steepness (S) were used as main factors in the USLE in consideration of the soil, not by the land use or land cover. Second, the soil erodibility increased in paddy soils where it is low in soil content, and the very fine sandy loam exists. Analysis of the slope length showed that the value of a flat ground was 1, and the maximum value was 9.17 appearing on the steep mountain. Soil erodibility showed positive relationship to a slope. Third, the potential soil erodibility index (PSEI) showed that it is high in the PSEI of the areas of steep upland and orchard on the slope of mountainous region around Dokjigol mountain, Dunji mountain, and Deummit mountain. And the PSEI in the same land cover was different depending on the slope rather than on the physical properties in soil. Forth, the analysis of land suitability in soil erosion explained that study area had 3,672.35ha showing the suitable land, 390.88ha for the proper land, and 216.54ha for the unsuitable land. For unsuitable land, 8.71ha and 6.29ha were shown in fallow uplands and single cropping uplands, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.3
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• pp.158-164
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• 2001

The purpose of this study was to assess the runoff of nitrogen derived from pig manure under upland condition. Bare and maize cultivated conditions were compared to estimate the effect of plant on the runoff loss of nitrogen and other nutrients by application of pig manure. Soil used in this experiment was sandy loam, and the fermented pig manure was applied at the rate of 0, 50, and $100ton\;ha^{-1}$. The amount of runoff was measured after every rainfall and water samples were analyzed for nitrate and other cations. Runoff was increased with the rainfall, but was depended on the application rate of pig manure at both bare and maize cultivated plots. Concentrations of nitrate in runoff at 0, 50 and $100ton\;ha^{-1}$ application of pig manure were higher at the maize cultivated plots than those at bare plots by 86.9, 42.9, and 33.6%, respectively. However, total mass of nitrate by runoff loss was higher at the bare plot ranging from 1.34 to $3.15kg\;NO_3-N\;ha^{-1}$. The equivalent ratio of nitrate to sum of cations in runoff was higher at the bare plot than that of maize cultivated plots. The concentration of cations in runoff was in the order of K> Mg> Na> Ca.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.7-13
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• 1985

The cropping management factor, C, in the Universal Soil Loss Equation (USLE) has been measured on a newly reclaimed Yesan sandy loam of 20% slope under various cropping system. Soil losses measured from lysimeter were 12.9, 5.4, 3.1, and 1.2 ton/10a for clean tilled, corn, barley-soybean, and grass, respectively. The values of C to be utilized in Soil-Loss Equation was obtained as fallows; corn 0.47, upland rice 0.34, barley-soybean 0.18, barley-sweet potato 0.10, grass 0.08, barley-corn 0.34, wheat-soybean 0.25, barley-corn (Soybean) 0.42, barley-corn (sweet potato) 0.37, wheat-sesame 0.20, barley-red pepper 0.18, red pepper 0.32, sesame 0.28, potato-soybean 0.26, respectively. According to the comparisons between the actual soil loss measured by lysimeter and the soil loss predicted by the USLE, the smallest difference of both method came from barley-soybean while the largest came from corn.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.48-58
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• 1986

In order to eluciate the factors affecting the injury caused by simetryne(2-methyl thio-4,6-bis(ethylamino)-S-triazine) to rice plants of Tongil variety(Indica ${\times}$ Japonica), the leaching properties of simetrynes, compared with Japonica varieties, Mangyeung and Sadominori were investigated. Bioassay technique and $^{14}C$-simetryne for leaching study and bioassay for the characteristics of the rice plants were employed. The leaching range of simetryne was very narrow regardless of soil types under upland soil conditions but it increased little in Silt clay soil and greatly in Sandy loam soil under flooded soil conditions. The amount of the roots of Tongil Jas a little more than that of Mangyeung and the roots of the Tongil mostly distributed near the surface soil while those of Mangyeung rooted deep into the soil. The foliage area and the rate of transpiration of Tongil were larger and greater than those of Mangyeung by 1.3 times and 1.65 times, respectively. The sensitivity of Tongil to simetryne was about 3 times larger than that of Sadominori in water culture.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.123-135
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• 2006

Spatial variability and distribution map of soil properties and the relationships between soil properties and crop yields are not well characterized in agroecosystems that have been land leveled to facilitate more cultivation of the new reclaimed sloping highland. Potato, onion, carrot, Chinese cabbage and radish were grown on the coarse sandy loam soil in 2004. Soil moisture content, soil penetration resistance and crop yield were sampled in the $10m{\times}50m$ field consisted of five plots. Sampling sites of each cultivation plot were 33 for the soil moisture, 11 for the soil penetration and 33 for the crop yield. The results of semivariance analysis, most of models were shown spherical equation. The significant ranges of each spatial variability model for the soil moisture, soil penetration and crop yield were broad as 33-35 meters in the potato cultivation plot, and that in the Chinese cabbage cultivation plot was narrow as 5-6 meters. The coefficient of variances (C.V.) of moisture, penetration and yield were various from 14 to 59 percents in five cultivation plots. The highest C.V. of potato yield was 59 percents, and that of the radish cultivation plot was as low as 14 percents. The required sample numbers for the determination of soil moisture content, soil penetration resistance and crop yield with error 10% at 0.05 significant level were ranged 8-40 for soil moisture, 7-25 for soil penetration and 424-4,678 for crop yield. The variogram and distribution map by kriging described field characteristics well so that the spatial variability would be useful for soil management for better efficiency and precision agriculture in the reclaimed highland.