• Proceedings of the Korea Water Resources Association Conference
• /
• 2011.05a
• /
• pp.283-287
• /
• 2011

농업비점오염원의 오염원 관리를 위해서는 오염물질의 발생과 운반에 직접적으로 영향을 미치는 농업수문학 기술에 바탕을 두고 우리나라의 집약농업의 특성을 정확히 반영할 수 있는 최적관리방법의 개발과 비점오염저감효과를 검증할 수 있는 현장실험이 수반되어야 한다. 따라서 본 연구에서는 지표피복재를 이용하여 밭의 토양침투를 증가시고 유속 및 유출량 감소를 통해 토양유실과 비점오염원을 저감하고자 하였다. 실험방법은 실제 영농과 동일하게 무를 재배한 뒤 볏짚거적을 이용하여 밭의 토양 표면을 피복하여 유량과 수질농도를 측정하였다. 연구기간 동안 총 3차례(2010년 9월 9~12일, 9월 21일, 10월 2~3일)의 강우가 발생하였고, 이때 발생한 강우량은 각 359.2 mm, 49 mm, 28.8 mm이였다. 각 시험포에서 볏짚거적으로 인해 저감된 유출량의 저감효율은 볏짚거적을 피복하지 않은 나지상태의 밭 보다 약 33∼75%의 저감효과가 있는 것으로 나타났다. 75%의 유출률 저감 효과가 가장 크게 나타난 강우사상은 30 mm 이하의 강우가 발생한 10월 2~3일의 강우사상에서 나타났다. 강우량과 강우강도는 28.8 mm와 1.92 mm/hr으로 나타났으며, 이때 발생한 유출량은 나지에서 $0.36\;m^3$, 볏짚거적을 피복한 시험포에서는 $0.08\;m^3$이 발생하였다. 나지상태와 볏짚거적을 피복한 시험포의 오염부하의 값을 비교한 결과 볏짚거적을 피복한 시험포에서 $BOD_5$ 항목은 64.3%, SS 80.8%, $COD_{Mn}$ 66.7%, DOC 80.2%, T-N 56.6% 그리고 T-P 56.1%의 오염부하 저감효과가 나타났다. 본 연구의 결과와 같이 지표를 볏짚거적으로 피복할 경우 시험포에서 유출시작 시간 지연효과와 강우에 의한 첨두유출량 및 유출량 감소 효과가 나타나는 것으로 나타났으며, 연구결과는 농업 비점오염원의 최적관리를 위한 과학적 근거자료 제공 및 기초자료로 활용할 수 있을 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1242-1246
• /
• 2010

호우기간 동안 내리는 빗방울의 타격에 의해 흙 입자는 침출수와 함께 이동하여 지표 아래 공극을 막는다. 다져진 지표면은 유출과 토양 유실의 원인이 된다. 발생원으로부터 유실되는 토양을 Polyacrylamide(PAM)과 지표피복재를 이용하여 저감하는 연구를 하였다. PAM은 토양 입자의 결합력을 강화시키고 이탈을 방지하여 토양 유실을 감소시키는데 효과적이다. 이 연구의 목적은 PAM을 덧붙인 볏짚거적, 볏짚거적+톱밥, 볏짚거적+왕겨 등을 이용하여 인공강우 동안 토양 유실을 저감하는 효과를 조사하는 것이다. 실험은 1시간 동안 강우를 모의했으며, 실험 도중에 6~7회 수질 샘플을 채취하였다. 초기유출시간은 총 4차 실험중에 2차를 제외한 나머지에서 볏짚거적+왕겨+PAM이 가장 느리게 유출되었다. SS와 탁도 항목에서 1차 실험을 제외한 나머지 실험에서 볏짚거적+톱밥+PAM이 효과적이었다. 단순히 PAM을 사용하는 것보다 잔여물(residue)을 같이 혼합한 피복재료가 토양 유실과 유출을 저감하는데 더욱 효과적인 것으로 나타났다. 본 연구 결과는 향후 농촌지역에 토양 유실저감에 필요한 자료로 활용할 수 있을 것이라 판단된다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.894-898
• /
• 2012

본 연구는 밭에서 발생하는 비점오염물질을 저감하기 위하여 기존의 볏짚거적을 이용한 저감방법에 PAM과 Gypsum을 처리하였을 때, 표면유출량과 기저유출량, 유사량 그리고 탁도 등에 미치는 영향을 모의하고자 하였다. 연구 방법은 인공강우 시험기와 토양상자를 이용한 실내실험을 통하여 지표피복재의 종류와 강우강도 그리고 경사도에 따른 직접유출량과 유사량을 측정하고 비교하였다. 경사도 (10 %, 20 %)와 강우강도 (30 mm/hr) 그리고 지표피복재의 종류에 따라 실험처리를 하였으며, 지표피복재는 볏짚(Rice straw mat)+PAM (Polyacrylamide)+Gypsum, 볏짚+PAM+톱밥 (Sawdust)+Gypsum, 볏짚+PAM+왕겨 (Chaff)+Gypsum으로 구분하여 제작하였다. 실험 결과 볏짚을 이용한 다양한 피복소재를 이용해 지표를 피복할 경우, 대조구(나지)에 대비 유출수량, 토양유실 그리고 탁도 저감에 큰 효과가 있는 것으로 나타났다. 지표를 피복한 처리구의 평균 표면 유출수량은 대조구와 비교할 때 72~85.6 %가 저감되었다. 그러나 동일조건의 Gypsum을 첨가하지 않은 연구와 비교 시 Gypsum의 혼용으로 인한 효과는 크지 않은 것으로 나타났다. 세분화된 강우강도와 경사도 조건에 따른 실험이 필요하지만 본 연구의 결과에 기초할 때, 지표의 피복과 토양개량제를 첨가하는 방법은 강우 시 발생하는 표면유출수와 유사 그리고 탁수를 저감시킬 수 있는 최적영농관리방법 (Best management practice)의 하나로 판단된다.

• Journal of Korean Society of Forest Science
• /
• v.13 no.1
• /
• pp.67-78
• /
• 1971

The measures of contour-terracing with sod has been executed as a major measures for hillside erosion control works for a long time in Korea. It is, however, recognized that pair terracings make a new slope-face having the more steeper degree of slope between the upper and the lower terraces on hillsides and it also does not contribute for establishing the natural vegetation-cover by penetration of pioneer seeds on the slope faces or cut-faces of hillsides. The study was therefore conducted in connection with the above problems on the cut-face having slope of $40^{\circ}$ and 1.6 meter in slope length with clay soils. Plot allocation for the experiment consists of 3 kinds of 3 replica plots having each $1.6m^2$ of slope area, i. e., the control plot with direct seeding on slopes only ($T_1$), the covering plot with the straw-mats after seeding on slopes ($T_2$) and the seeding plot after covering with the straw-mats. ($T_3$). The main results obtained may be summarized as follows : 1. Effects of the straw-mat mulchings on surface soil loss control:-The total amount of soil losses from each treatments are measured as 4,651 gr from $T_1$, 163 gr. from $T_2$ and 2,891 gr. from $T_3$ treatment respectively. (Refer to table No. 2, 3 and 4). In short, it is recognized that effect of $T_2$ treatment is compared as 28.5 times than that of $T_1$ treatment and 17.7 times than that of $T_3$ treatment respectively. Effect of $T_3$ treatment compared with $T_1$ treatment is also such recognizable as 1.6 times in control of surface soil losses on a slope face. 2. Effect of the straw-mat mulchings on soil moisture content on slopes; -Average per cent of surface soil moisture content by treatments show as 21.60 at the $T_1$, 23.04 at the $T_2$ and 22.21 at the $T_3$ treatment respectively and that of subsurface soil moisture content by treatment show as 23.81 at the $T_1$, 26.16 at the $T_2$ and 24.81 at the $T_3$ treatment respectively. The variance of soil moisture content by treatments was highly significant (Refer table No. 7, 8 and 9). 3. Effect of the straw-mat mulchings on vegetation establishment;-Average numbers of germination by treatments are counted as 237 Nos. at the $T_1$, 246 Nos. at the $T_2$ and 262 Nos. at the $T_3$ treatment plots and the vegetation coverage on ground was almost same as about 90% of covers in all treatments. This effect is more or less lower than that of surface soil erosion control. 4. Regarding the effect on surface soil erosion control, the straw-mat mulchings would be effective as a new measures for control of soil erosion on erosion susceptible lands such slope-faced bare-lands as cut-fill faces, mass-movement faces and bare hillsides.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.1036-1040
• /
• 2008

수질 개선을 위한 많은 노력과 투자를 하고 있다. 하지만 농경지의 부적절한 관리로 인한 토양유실로 발생하는 오염은 여전히 큰 비중을 차지하고 있다. 특히 강원도는 산이 많아 농경지의 대부분이 경사지에 위치하고 있다. 경사진 농경지는 그 특성상 토양유실이 일어나기 쉬운 조건에 있다. 경사지의 토양 유실은 지력을 저하시킨다. 또한 토양과 함께 유실되는 유기물 및 양분은 농경지의 손실이며 주변 수역으로 유입되어 수질 오염의 원인이 된다. 이런 토양 유실은 직접유출량과 큰 연관이 있다. 본 연구에서는 강우강도, 경사도, 피복도를 동일하게 조정할 수 있는 실내 인공강우 시험기를 사용하여 직접유출율을 산출하였다. 피복재료는 볏짚거적을 사용하였다. 강우강도는 30 mm/h와 60 mm/h 그리고 경사도는 10 %와 20 %를 사용하였다. 볏짚거적 피복처리는 0 kg/ha (나지), 3,000 kg/ha (볏짚 1겹), 6,000 kg/ha (볏짚 2겹), 10,000 kg/ha (볏짚 3겹) 이었다. 강우강도 30 mm/h, 경사도 10 % 인 시험포는 볏짚 1겹으로만 피복하여도 직접유출율이 0.77 %로 유출이 거의 발생하지 않았다. 강우강도 30 mm/h, 경사도 20 % 인 시험포의 직접유출율은 피복이 볏짚 1겹인 경우 16.9 %, 볏짚 2겹인 경우는 0 %로 매우 낮았다. 강우강도 60 mm/h, 경사도 10 % 인 시험포는 피복이 볏짚 2겹인 경우 3.4 % 로 매우 낮았다. 강우강도 60 mm/h, 경사도 20 % 인 시험포는 피복이 볏짚3겹인 경우 16.58 % 로 나타났으며, 볏짚 피복을 4겹 이상으로 할 경우 더 큰 저감 효과를 가져 올 수 있을 것으로 판단된다. 따라서 본 연구의 결과로 경사진 농경지의 직접유출량을 저감시켜 토양유실과 탁수를 줄이기 위한 방법으로 볏짚 피복을 선택하면 효과적인 것으로 사료된다.

• Journal of Korean Society of Forest Science
• /
• v.81 no.1
• /
• pp.53-65
• /
• 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 Korean Society of Forest Science
• /
• v.27 no.1
• /
• pp.5-14
• /
• 1975

Eroded sloping faces in hillsides including cut-bank slopes are liable to both surface erosion and land-slides and the key to control of these form of erosion lies with drainages of excessive run-off and dense vegetation establishment including surface mulching on the slopes. Micro-plots having $1.6m^2$ (1 metre in width and 1.6 metres in slope length, and 1:1.2 in gradient) of banking slopes on coarse sand soil are used to establish the order of magnititude of the difference in controlling of soil erosion and water runoff, and in rating of survival, performed on the repetetions of three-experiment plots consisted of such three levels as 90% (Dense), 70% (Moderate), and 50% Sparse of the density of the coarse straw-mat mulchings. The main results obtained may be summarized as follows: 1. The rates of surface runoff are calculated as 13.13% from the dense mulchings, 14.21% from the moderate mulchings, and 15.57% from the sparse mulchings respectively. 2. The total amounts of soil loss are measured as about 1.24 tons/ha. from the dense mulchings, about 1.33 tons/ha. from the moderate mulchings, and about 1.44 tons/ha. from the sparse mulchings respectively. The amounts of soil loss under these treatments are much lower than the standard of erosion in USDA (1939 Bennet). 3. Average numbers of germination by treatment are counted as 80 seedlings at the dense mulchings. 132 at the moderates and 121 at the sparse respectively. Large numbers of seedling are suppressed and died during the growing at the dense mulchings due to mainly mechanical obstruction. 4. Coarse straw-mat having about 70% of coverage density is the most suitable mulches in both soil erosion control and vegetation establishment. 5. The method of coarse straw-mat mulching is the most recommendable measure for establishing the vegetation cover with less soil erosion on the denuded gentle slopes in hillsides at present in Korea.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.2
• /
• pp.29-36
• /
• 2013

The objective of the research was to describe the effect of straw mat cover and soil amendments on the reduction of runoff and non-point source load from steep sloped highland agricultural fields. Four $5{\times}30$ m plots on sandy loam soil with 28 % slope were prepared. Experimental treatments were bare (control), rice straw mat cover (3,000 kg/ha) (S), PAM (5 kg/ha)+Gypsum (1 ton/ha) (PG) and rice straw mat cover+PAM+Gypsum (SPG). A variety of lettuce was cultivated and runoff was monitored during a growing season in 2011. Natural monitoring was conducted to three times. Runoff rate of S, PG and SPG plots were significantly lower than those of control plot. Especially, the runoff rate is zero in SPG plot at a first rainfall events. The reduction rate of runoff from the S, PG and SPG plots was 30.8 %, 29.0 % and 81.8 % compared to control plots, respectively. The reduction rate of NPS pollution load of S, PG and SPG was ranged of 50~90 %, 30~70 % and 90~100 %, respectively. Yield of lettuce from S, PG and SPG plots was respectively 400 (567 kg/ha), 320 (453 kg/ha) and 760 (1,067 kg/ha) that of compared to control plots greater than that from control plots (140 kg/ha). We speculated that the experimental treated plots could hold more nutrients and moisture than the control and helped the crop grow healthier. When analyzing the above results, in terms of reduction of runoff and NPS pollution load and crop yields, SPG experimental treatment had the best effect. It was concluded that the use of rice straw mats cover and soil amendments on soil surface could not only reduce the NPS pollution loads in receiving waters but also help increase the crop yield.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.54 no.2
• /
• pp.95-102
• /
• 2012

The objective of this research was to experimentally test the effect of rice straw mats on the reduction of runoff, sediment discharge and turbidity under a laboratory scale. We used the small runoff plots of 1 m ${\times}$ 1 m ${\times}$ 0.65 m ($L{\times}W{\times}H$) in size filled with loamy sand. Experimental treatments were bare (control), rice straw mat cover of straw mats + PAM + Gypsum (SPG), rice straw mats + Chaff + PAM + Gypsum (SCPG) and rice straw mats + Sawdust + PAM + Gypsum (SSPG); slope of 10 % or 20 %; and rainfall intensity of 30 mm/hr. Runoff volume and rate of covered plots were significantly lower than those of control plot. Average runoff rate of covered plots, slope of 10 % and 20 %, decreased 85.6 % and 72 % in respectively. Sediment reduction ratio was more than 99 % regardless of slope. The differences runoff and sediment discharge among different cover materials were not significant. It was also shown that even if runoff reduction by surface cover were low, sediment discharge reduction could be very significant and contribute to improve the water quality of streams in sloping agricultural regions. It was concluded that the use of straw mat and soil amendments (PAM and Gypsum) on sloping agricultural fields could reduce soil erosion and muddy runoff significantly and help improve the water quality and aquatic ecosystem in receiving waters. But mixing effect of PAM and Gypsum was minimal.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.4
• /
• pp.37-44
• /
• 2013

We have examined the effect of rice straw mat (RSM) on the reduction of non-point source (NPS) pollution loads at soybean cultivations. The slope of the experimental plot was about 3 %. Monitoring was carried out for four years at conventional tillage (CT) in 2008~2009 years and RSM covered tillage in 2010~2011 years. Thirty-two rainfall events were monitored and analyzed during the study period. During the 2 years of 2008 and 2009, 20 rainfall runoff events were monitored. But in 2010 years, only 2 rainfall runoff events could be monitored. And in 2011 years, 10 rainfall runoff events was monitored. It was because the RSM cover enhanced infiltration and reduce runoff in 2010 and 2011. Average NPS pollution load (organic matters) of the RSM covered field was reduced by 72.1~94.2 % compared to that of CT field. NPS pollution load of TN and TP reduced by 67.5 % and 55.7 %, respectively. Especially, SS pollution load was reduced by 97.3 %. Based on the results, rice straw mat cover was considered as a promising best management practices (BMP) to reduce NPS pollution load. However, it was recommended that the results are limited to the field conditions and the same experiments must be performed on different soil textures, slopes, and crops if it is applied to the development of policies.