• 한국농공학회논문집
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• 제55권4호
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• pp.121-131
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• 2013

This study focused on the sediment reduction effects of VFS (vegetative filter strip) systems for the general characteristics of uplands in Korea. General conditions of upland fields were investigated through national scales of annual agricultural statistics. 7-15 % of slope with loam soil was the dominant types of uplands, and the hydrologic soil group feature usually belong to Type B. The common sizes of uplands were bigger than 0.1 ha and less than 0.2 ha, and 86.2 % of them account for less than 1.0 ha. With this information, 0.1 ha, 0.5 ha, and 1.0 ha of uplands with various shapes and 7-15 % of slopes were considered for the VFS system simulations. 20 mm, 40 mm, and 100 mm of daily precipitation were applied. As a result, the trapping efficiencies of VFS systems were obtained 37.4~100 % for 7 % slope and 18.1~98.0 % for 15 % slope of the less than 1.0ha of uplands. As rainfall increased, sediment loads also increased with slope and slope length increase. Also as size and slope of uplands and slope length increased with VFS length decrease, the trapping efficiency decreased for the same amount of rainfall. The optimum lengths of VFS systems for the givien upland conditions were suggested based on the modelling results with condition of VFS length less than 20 % of upland areas.

• 농업과학연구
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• 제37권3호
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• pp.435-449
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• 2010

Soils in the sloping uplands in Korea are subject to intensive land use with high input of agrochemicals and are vulnerable to soil erosion. Development of the environmentally sound land management strategy is essential for a sustainable production system in the sloping upland. This report addresses the status of upland agriculture and the best management practices for the uplands toward the sustainable agriculture. More than 60% of Korean lands are forest and only 21% are cultivating paddy and upland. Uplands are about 7% of the total lands and about 62% of the uplands are in the slopes higher than 7%. Due to the site-specificity of the upland, many managerial and environmental problems are occurring, such as severe erosion, shallow surface soils with rocky fragments, and loadings of non-point source (NPS) contaminants into the watershed. Based on the field trials, most of the sloping uplands were classified as Suitability Class III-V and the major limiting factor was slope and rock fragments. Due to this, soils were over-applied with N fertilizer, even though N rate was the recommendation. This resulted in decreases in yield, degradation of soil quality and increases in N loading to the leachate. Various case studies drew management practices toward sustainable production systems. The suggested BMP on the managerial, vegetative, and structural options were to practice buffer strips along the edges of fields and streams, winter cover crop, contour and mulching farming, detention weir, diversion drains, grassed waterway, and slope arrangement. With these options, conservation effects such as reductions in raindrop impact, flow velocity, runoff and sediment loss, and rill and gully erosion were observed. The proper management practice is a key element of the conservation of the soil and water in the sloping upland.

• 한국농공학회논문집
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• 제56권5호
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• pp.89-99
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• 2014

The goal of this study was to evaluate sediment reduction effects of VFS (vegetative filter strip) applied for Iksan area in Saemangeum watershed. This study simulated runoff and sediment load from different types of uplands using VFSMOD-W. The general upland characteristics of the study area was investigated to build reasonable scenarios of the simulation. The simulation scenarios were designed by various areas, shapes, and slopes of uplands. Grass mixture was selected as VFS vegetation and the size of VFS was fixed as 10 % of uplands area. Additionally 50mm, 100mm, 150mm of daily rainfall were applied for the runoff and sediment simulation. As results, the calculated runoff and sediment loads were obtained $20.7{\sim}1,030.6m^3$ and 568.4~675,731.4 kg for the range of 0.1~1.0 ha of uplands with 7 % and 15 % slopes. The reduction effects on runoff and sediment were obtained 5~10 % and 21.0~47.7 % respectively from VFS applications. The VFSMOD-W simulations showed that runoff tended to increase as upland area and amount of rainfall increased while sediment increased when slope, length and area of uplands and amount of rainfall increased. These results indicated that rainfall amount and upland size are the critical factors for the generation of runoff and sediment load. In order to support this conclusion, further studies such as, long term monitoring, field experiments, and to calibrate and evaluate the model are necessary.

• 한국수자원학회논문집
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• 제51권6호
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• pp.535-542
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• 2018

본 연구에서는 VFSMOD-W 모형을 활용하여 새만금 유역의 초생대 기법 적용에 따른 유사저감효과를 예측하고자 하였다. 먼저 모형의 신뢰도 확보를 위해 새만금 유역 내 초생대 실측치를 활용하여 매개변수를 보정하였으며, 새만금 유역 내 밭경지 특성을 파악하여 이를 토대로 모의 시나리오를 개발하였다. 다양한 밭경지 특성을 반영하기 위해 개발된 모의시나리오는 밭경지 규모 1 ha, 5 ha, 10 ha로 밭의 폭과 길이 비는 1 : 1를 적용하였으며, 밭의 경사는 7%, 15%를 고려하였다. 또한 강우조건은 50 mm, 100 mm, 150 mm, 200 mm 일강우량을 적용하였다. 그 결과, 초생대의 유출저감효과는 밭경사 7%와 15%에 대해 2.9~13.5%, 2.9~12.1%로 각각 나타났으며, 유사저감효과는 33.8~97.0%, 27.1~85.9%로 각각 나타나 유출저감효과에 비해 상대적으로 높은 저감효과를 나타내었다. 유출 및 유사 발생에 영향을 미치는 밭규모, 경사 및 강우량 인자에 따라 초생대 효과는 큰 차이를 나타내었다. 본 모의 결과를 바탕으로 새만금 유역내 밭경지 규모 10 ha 미만, 경사 15% 이내의 조건에서 밭면적 10% 규모로 초생대를 조성할 경우 유사저감 효과를 기대할 수 있을 것으로 사료된다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.771-776
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• 1999

RUSLE was applied to estimate annual soil loss from two small agricultural watersheds in Kangwon-do, Korea. GIS input parameters were prepared by using DEMs and soil maps prepared by the NGIS project and Rural Development Adminstration, respoctively. RUSLE parameters were prepared based on existing data and equations. Estimated annual soil loss was graphically presented to easily visualize the large soil loss area. Uplands and vineyards proved to be the two greatest sources for soil erosion. It was suggested to develop effective management practices to reduce the soil erosion from uplands and vineyards.

• Journal of Applied Biological Chemistry
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• 제50권1호
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• pp.22-28
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• 2007

Most of the uplands in alpine regions during off-season are left as bare soil and thus vulnerable to severe erosion due to the inherent topographical conditions. Appropriate management strategy to cope with this problem is urgently needed, yet few researches have been reported on the effects of winter cover crop and management on soil erosion. We assessed effects of ryegrass (Lolium multiflorum) as cover crop, green manure or mulching residue on soil erosion and quality through field and segment plot lysimeter experiments in alpine uplands. Ryegrass successfully adopted to winter in alpine region based on biomass, nutrient contents, and vigors of top and root systems. Incorporation of ryegrass into soil maintained soil fertility, nutrient uptake, and yield of cabbage exerting potential use as green manure. Cultivation of ryegrass suppressed occurrence of Chinese cabbage pests. Surface coverage by ryegrass as cover crop and mulching residue significantly reduced soil loss up to 96%, when combined with soil conservation management practices. Results revealed maintaining cover crop over winter was beneficial in reducing soil erosion, and sustaining soil quality and Chinese cabbage productivity. This study suggested winter cover crop, followed by green manure and mulching, and conservation tillage system could be one of the best management practices in alpine sloping uplands cultivating Chinese cabbage.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.68-68
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• 2017

The status of corn genetic diversity in the uplands of Sarangani in Southern Philippines was investigated using 12 morphological traits subjected to multivariate statistical analyses. Information about traditional farming, post-harvest and storage practices were also elicited especially in relation to losses of traditional varieties, a phenomenon known as genetic erosion. While a handful of farmers still plant traditional corn varieties in the remotest areas, a significant number had already shifted to genetically modified corn. Furthermore, principal component analysis (PCA) reduced the 12 morphological traits into 5 principal components and identified ear length and ear weight to be major contributors to variation. Cluster Analysis, on the other hand, formed two distinct groups but failed to give information about intra-cluster variability among the 32 collected corn accessions. These results warrant that more informative morphological traits and that molecular markers will be used to obtain a better picture of genetic diversity in Sarangani upland corn. Molecular analysis is also needed to establish genetic identities of these cultivars and to detect gene introgression from GM varieties into the gene pool of farmers' corn varieties. These analyses are imperative for the conservation of traditional corn varieties before they disappear in the Sarangani uplands because of shifting priorities of upland farmers.

• 한국초지조사료학회지
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• 제1권2호
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• pp.7-14
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• 1979

• 한국토양비료학회지
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• 제11권3호
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• pp.175-194
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• 1979

The soil organic matter contents in arable land are generally low in Korea. Thus it is generally agreed that the application of organic materials to soils would be much beneficial. Present paper is a review on the effectiveness of organic mat ter application in uplands and lowlands. 1. The effect of organic matter application in uplands are of more clear and simple to explain as compared to that in lowlands. In uplands, appropriate application of organic matters such as compost and various crops residues improves the physical properties of soils leasing to increased water holding capacity, better aeration, and decrease in soil erosion. 2. In lowland, rice soils under water logged conditions the effect of organic matter application on rice yield is not straight borward and demands more refined knowledges for the interpretation of it. 3. It is found that the application of compost in rice soils is more effective when nitrogen fertilizer application is limited it dicating that nitrogen contained in the organic maerials can become available to rice plant and plays an important role for increased yield of rice under the condition where nitrogen fertilizer supply is limited. 4. Application of organic matter does not always bring about the desirable effects. Very often the organic matter application results in more intensive soil reduction leading to the accumulation of harmful substances which would can cancel out the positive effects of organic matter. This is partiunlarly true in poorly drained soils. 5. Rice straw or compost, when applied rice soils, supply sizeable amounts of available silicate to rice plant resulting in yield increase. 6. Although the effectiveness of organic matter application on rice yield in short term experiments is not consistent due to many reasons, the long term effect of organic matter is significant. 7. The term of the $O.M/SiO_2$ ratio in rice soils can serve as a criterion for the judgement of whether organic matter or silicate fertilizer is needed to be applied in a certain soil.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권3호
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• pp.139-148
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• 2022

Saxifraga hirculus is classified as a vulnerable plant species in Europe, and it is confined to base-rich flushes in the British uplands. However, a lack of available information about its conservation status hampers the development of adaptive strategies for its in-situ conservation, especially with respect to grazing. To assess the effectiveness of sheep grazing in maintaining viable populations of S. hirculus, we compared the community dynamics of the vegetation in a base-rich flush over 44 years in two plots: one sheep-grazed under business-as-usual sheep grazing densities and the other fenced to exclude grazing. The plots were established in 1972, and the abundances of all vascular plants, bryophytes, and litter were measured at six intervals until 2016. Our results showed that although the presence of S. hirculus was maintained in both plots over the 44 years, it declined and reached a minimum between 1995 and 2010, when it was close to extinction. Since 2013, Saxifraga has recovered only slightly. Interestingly, the S. hirculus response appeared to be independent of grazing treatment, but it mirrored wider changes in the vegetation composition and structure within the flush over the 44 years. These changes are similar to others reported in broader uplands that have been attributed to a combination of reduced nitrogen and sulfur deposition and global warming. Thus, the simple adaptive management approach of "just managing" sheep grazing appeared ineffectual for preserving the S. hirculus population. S. hirculus showed signs of recovery at the end of the study period within this base-rich flush.