• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.5
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• pp.81-90
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• 2016

Due to droughts and water shortages causing severe damage to crops and other vegetations, much attention has been given to efficient irrigation for upland farming. However, little information has been known to measure soil moisture levels in a field scale and apply their spatial variability for proper irrigation scheduling. This study aimed to characterize the spatial variability and temporal stability of soil water contents at depths of 10 cm, 20 cm and 30 cm on flat (loamy soil) and hill-slope fields (silt-loamy soil). Field monitoring of soil moisture contents was used for variogram analysis using GS+ software. Kriging produced from the structural parameters of variogram was applied for the means of spatial prediction. The overall results showed that the surface soil moisture presented a strong spatial dependence at the sampling time and space in the field scale. The coefficient variation (CV) of soil moisture was within 7.0~31.3 % in a flat field and 8.3~39.4 % in a hill-slope field, which was noticeable in the dry season rather than the rainy season. The drought assessment analysis showed that only one day (Dec. 21st) was determined as dry (20.4 % and 24.5 % for flat and hill-slope fields, respectively). In contrary to a hill-slope field where the full irrigation was necessary, the centralized irrigation scheme was appeared to be more effective for a flat field based on the spatial variability of soil moisture contents. The findings of this study clearly showed that the geostatistical analysis of soil moisture contents greatly contributes to proper irrigation scheduling for water-efficient irrigation with maximal crop productivity and environmental benefits.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1586-1590
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• 2006

In order to calculate the actual erosion according to the universal soil loss equation (USLE) and to estimate the impact of land use on soil erosion in Saemangeum, it is important to know the C-factor. Based on the USLE crop-growth stages, the cover-management C-factors were calculated for the main crop and crop rotation systems by National Institute of Agricultural Science and Technology. Combining this result with statistical data about crop cultivation area and crop rotation systems, C-factors of each administrative district in Saemangeum watershed were calculated. The range of C-factors were between 0.28 and 0.35. High C-factor value was obtained with Gimje (C = 0.35) and small C-factor values were found in Wanju (C = 0.28) and Jeongeup (C = 0.29). With this result, calculated annual soil loss was 2,804,483 ton per year. Because of the lack of sufficient statistical data about crop rotation systems, further studies are required on collecting field survey data.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.67-73
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• 1992

This study was carried out to investigate the effects of soil improver on the population density and composition of microarthropods in the upland which cultivated pepper consecutively. We have treated soil improver sucf as zeolite, compost, ca, sio2 , and integrated improvement i. e. treated zeolite, compost, ca, and deep cultivate ; 20 cm. We sampled soil to collect soil microarthropods from a week to 15 months after treament at each site by soil-corer and extracted 48 hours in berlese- tullgren funnel. We have classified 16 families, 35 species diversity index of soil microarthropods are highe in the integrated improver and compost site than those found in any other sites. We suggest that soil improvement effrcts of integrated improved site are influenced by compost.

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.697-699
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• 2006

To find out the best complex fertilizer for high yielding of rapeseed crop, experiment was conducted on complex fertilizers at the experiment field in upland of rapeseed in Mokpo Experiment Station, Nat'l Institute of Corp Science, RDA, Korea. Experiment was laid out in randomized complete block (RCBD) design. The effects of complex fertilizer (22-22-11) on the number of branches, pod length, percentage of seed set and seed yield were highest but on the plant height, ear length, and number of pods per ear were negligible. On th basis of the results reported above, for getting higher yield of rapeseed crop, among the tested fertilizers complex fertilizer (22-22-11) gave the superior performance and is recommended for application.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.24-28
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• 1997

The field experiment for field desalinization by precultivation of orchard crops were carried out to evaluate relationship between the varieation of chlorine contents of soil and crop uptake in the upland diverted from paddy field. After harvest of grass crops, soil samples were taken for analysis of chlorine contents of soil layers. Regardless of kinds of grass crops cutivated, contents of soil chlorine were decreased comparing to non-crop plot. Chlorine content in plant harvested at just before the flowering stage was much higher than that of after flowering. Chlorine uptake and dry matter were increased in order of Italian ryegrass, Perennial ryegrass, and Sudan grass. Positive correlations were showed between chlorine uptake and dry matter. The content of soil chlorine decreased by higher yield of dry matter.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.233-237
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• 2011

This study was carried out to investigate the seedling establishment and yield of direct-sown Platycodon grandiflorus seeds cultured by three ridge width, 0.4, 0.8, and 1.2 m and four mulching materials, rice straw, rice bran, black plastic film, and no mulching in upland. Seedling establishment rate (70%) was the highest in rice straw mulched plot of 500 seeds/$m^2$ sowed and root yield after one year was also the highest in rice straw mulched treatment and followed by rice bran, no mulching, and black plastic film treatment. In this result, ridge width 120cm and rice straw mulching combined treatment was best for getting the highest seedling establishment ratio and seedling numbers per area. However, ridge width and mulching materials should be considered soil moisture content and weed population for saving labor cost.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.134-141
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• 2005

Cultivation of winter cover crops and its soil utilization for summer main crops in slope upland is very important at the respects of diminution of soil erosion and non-point pollution source. The effects of cover crop, hairy vetch as no-tillage or conventional tillage on prevention of soil erosion and reduction of chemical nitrogen fertilization were investigated in the slope upland with whiter clover living mulch (partial tillage) in Suwon for three years and with rye (conventional tillage) in Hongcheon for two years, respectively. In Suwon, amounts of soil lost by rainfall runoff decreased as much as 90% by hairy vetch-no tillage (HV-NT), white clover-partial tillage (WF-PT) together with the decrease of rainfall runoff compared to winter fallow with conventional tillage (WF-CT). In addition, amounts of weed also decreased as much as 80-90% by HV-NT and WF-PT. Corn yield decreased much at the plot of WF-PT mainly due to competition for soil water and nutrients between clover and corn at the early corn growth stage. On the contrary, corn yield increased by HV-NT compared to WF-CT regardless of weed control. In Hongcheon, amounts of soil eroded during winter season before corn seeding were reduced as much as 95% by cultivation of hairy vetch and rye compared to winter fallow. Amount of soil eroded during waxy corn growing season was reduced as much as 98% by HV-NT compared to WF-CT. Also, soil incorporation of hairy vetch and rye as green manure with conventional tillage at corn seeding time could reduce soil erosion as much as 70% compared to no soil cover with conventional tillage. Ear yields of waxy corn were increased 10% higher at hairy vetch green manure (HV-CT) without nitrogen fertilizer, 20% higher at HV-NT with standard nitrogen fertilizer, respectively than WF-CT. But ear yields of waxy corn were decreased by rye green manure (R-CT) and HV-NT at the condition of no nitrogen fertilizer. It was concluded that hairy vetch was better as winter cover crop to reduce both soil erosion and chemical nitrogen fertilizer simultaneously in slope upland than other cover crops.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.1-6
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• 2010

Allelopathic activity of rotation crop residues to common weeds and selectivity of crops were studied for developing an alternative weed control strategy in upland organic farming. All rotation crop residues with various ratios suppressed weed growth, but the growth of crop species stimulated a little when those were grown with the mixture of rotation crop residues except a few crop species. Among the rotation crop residues used in this study hairy vetch was the most effective, followed by Chinese milkvetch, barley and rye in suppression of weed growth. The 90:10 (crop:soil, v/v) treatments incorporation rate of crop residues such as hairy vetch and Chinese milkvetch suppressed completely the growth of all weed species tested in this study. The effect of crop residues on suppression of weed growth reduced to 90% when the incorporation rates decreased to 60% [60:40 (crop:soil, v/v). It was noticed that broadleaf weed species were more susceptible to rotation crop residues than grass weed species. In the influence of crop residues on the crop growth, no growth inhibition was found in red pepper, lettuce and perllia at any incorporation rates, but tomato, cucumber and corn were slightly inhibited in a few cases at their highest incorporation levels. This study demonstrated that rotation crop residues especially hairy vetch and Chinese milkvetch have high herbicidal effects against weeds without inhibiting the growth of crop species.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.419-424
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• 2008

Objective of this study was to evaluate the adaptation and the soil conservation effect of improved wild vine in sloped upland of highland about 600m from sea level in Korea. A mainly producing district of the improved wild vine in Korea was distributed 230m to 540m from sea level, and its rainfall ranged 1,200 to 1,700 mm. The lowest temperature was from -19.6 to $-25.4^{\circ}C$. Their soil texture was from sandy loam to clay loam, where drainage class was well drained and the contents of soil organic matter and total nitrogen in the improved wild vine's cultivation area were higher than those of Chinese cabbage's cultivation area in the highland. According to improved wild vine's cultivation methods, the amounts of soil erosion were 25.5,4.1, and $1.8MT\;ha^{-1}$ in clean culture, part sod + mulching, and nature sod, respectively. Those were below 30 to $80MT\;ha^{-1}$ of sloped upland at highland in Korea. The result suggests that it is possible to cultivate the improved wild vine over wintering at 600m of highland above the sea level. We can substitute the improved wild vine for Chinese cabbage in the highland for soil conservation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.327-331
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• 2009

Korean government has promoted the policy of chemical fertilizer reduction by 40% reduction from 2003 to 2013. Hairy vetch (Vicia villosa Roth) fixes nitrogen from the atmosphere and rye (Secale cerale L.) accumulates soil nitrogen to reduce potential nitrogen loss. The objective of this research was to identify optimum seeding rates of hairy vetch-rye mixtures in the central regions of Korea. The experiment of mixture rate was carried out for maximum production in 2006 and 2007. The best seeding rate mixture for maximum biomass production was 6.75 kg hairy vetch and 5 kg rye per 10a. Pure hairy vetch and rye were used as control. The nitrogen production of mixture treatments were higher than pure rye. The hairy vetch and rye mixture can scavenge potentially leachable nitrogen, while maintaining soil fertility by adding fixed nitrogen to the cropping system.