• Journal of Soil and Groundwater Environment
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• v.24 no.2
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• pp.1-7
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• 2019

The feasibility of using hydrated lime ($Ca(OH)_2$) was assessed in reducing soil loss in sloped land under field condition. During 6-month monitoring from May to October, amendment of hydrated lime (3%, w/w) to a test plot decreased soil loss by 76% as compared to the unamended plot. However, the growth of natural vegetation was hampered by hydrated lime addition due to pH increase. Hydrated lime can be used as an effective agent to prevent soil loss in sloped land, but additional treatments are needed to preserve vegetation growth, especially in crop fields.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.48-57
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• 2020

The objective of this study was to investigate the feasibility of organic compost for reducing soil loss in 25% sloped farm land. For the study, laboratory and field experiment were performed. After nine weeks monitoring in pot test, hardness of the amended soil with organic compost (1%~3%, w/w) showed two times higher than the control soil. Furthermore, soil loss of that was decreased by 95% under rainfall simulation test. From the result of laboratory experiment, organic compost with 2% (w/w) was applied for field experimental plot. After six month from April to September, the amount of soil loss became 67% of the initial, and the growth of natural vegetation was not hampered. Therefore, organic compost can be used as amendment materials to reduce soil loss in sloped farmland.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.682-688
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• 2009

A plane field and a sloped field located at low-land plane and alpine areas, respectively, were monitored with respect to runoff, water quality and fertilizer uses from March to December, 2008. Runoff volume and Non-Point Source (NPS) loads were estimated and analyzed with respect to fertilizer uses. Total TN and TP loads from the sloped field were higher than those from plane field because of larger chemical uses in the alpine field than in the plane field. Organic matter load from plane field was higher than that from sloped field because more organic compost was applied to plane field than to sloped field. Event Mean Concentration (EMC) of measured water quality indices were relatively higher in both fields. Organic matter load per 1 mm rainfall were higher in plane field and TN and TP loads per 1 mm rainfall were higher in sloped field than those in respective comparing field. It was concluded that the type and application method of fertilizer could play an important role in the estimation of NPS pollution loads and the development of Best Management Practices (BMPs). However, it was recommended that long-term monitoring is necessary to better describe the relationship between fertilizer uses and water quality from agricultural fields because numerous natural and management factors other than fertilizer also affect runoff quality.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.307-313
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• 2019

BACKGROUND: An intensive farming system may be of the most important source for agricultural non-point source (NPS) pollution, which is a major concern for agricultural water management in South Korea. Various management practices have therefore been applied to reduce NPS loads from upland fields. This study presents performances of sediment trap for reducing NPS and soil loss from rainfall runoff in cropland. METHODS AND RESULTS: In 2018 and 2019, three sediment traps (L1.5 m × W1.0 m × D0.5 m = 0.75 ㎥) and their controls were established in the end of sloped (ca. 3%) upland field planted with maize crops. Over the seasons, runoff water was monitored, collected, and analyzed at every runoff. Soils deposited in sediment traps were collected and weighed at the season end. Sediment traps reduced runoff amount (p<0.05) and NPS concentrations, though the decreased NPS concentrations were not always statistically significant. In addition, sediment traps had a significant prevention effect on soil loss from rainfall runoff in a sloped cropland. CONCLUSION: The results suggest that the sediment trap could be a powerful and the best management practice to reduce NPS pollution and soil loss in a sloped upland field.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.792-800
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• 2012

The study was performed to simulate the reduction efficiency of suspended solids (SS) for cultivated land located at riverine area at the Namhan River and the Bukhan River watershed sites (site A, B, C) under the rainfall conditions using HUFF & SCS UH-based VFS Design module of Web GIS-based VFSMOD System. The study indicates that the field 5% sloped, located at Bukhan River watershed (site A), requires at least 0.5 m width of Vegetative Filter Strip (VFS) to reduce 70% of SS while the field 10% sloped requires the at least 1.0~1.5 m width of VFS to reduce 70% SS, under the condition 106.2 mm of rainfall event and bell pepper or corn of crops. Against the conditions 95.1 mm of rainfall event and sweet potato or soy bean of crops, the field 5% sloped, located at Namhan River watershed (site B) requires at least 0.5 m width of VFS to reduce 70% of SS while the field 10% sloped requires at least 1.0 m width of VFS to reduce 50% SS. The crops sweet potato and soy bean are cultivated in the site C, located at Namhan River watershed, 1 m of VFS is capable of 64.0% and 62.0% of SS reduction against 102.6 mm and 151.2 mm rainfall conditions respectively, for the 5% sloped field. The result supports that VFS is one of most potential methods to reduce SS from cultivated area, which is environment-friendly hydrologic structure. The VFS design, however, needs to be simulated before its installation in the field, the simulation needs to consider not only various characteristics of the field but also different conditions affecting the VFS, using a model capable to consider a lot of factors.

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

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.260-267
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• 2010

As sloped farmland is subject to runoff and soil erosion and consequently require appropriate vegetative coverage to conserve soil and water, a field study was carried out to evaluate the impact of crop canopy coverage on soil loss and runoff from the experimental plot with three different textural types (clay loam, loam, and sandy loam). The runoff and soil loss were examined at lysimeters with 15% slope, 5 m in length, and 2 m in width for five months from May to September 2009 in Suwon ($37^{\circ}$ 16' 42.67" N, $126^{\circ}$ 59' 0.11" E). Red pepper (Capsicum annum L. cv. Daechon) seedlings were transplanted on three different dates, May 4 (RP1), 15 (RP2), and 25 (RP3) to check vegetation coverage. During the experimental period, the vegetation coverage and plant height were measured at 7 day-intervals and then the 'canopy cover subfactor' (an inverse of vegetation cover) was subsequently calculated. After each rainfall ceased, the amounts of soil loss and runoff were measured from each plot. Under rainfall events >100 mm, both soil loss and runoff ratio increased with increasing canopy cover subfactor ($R^2$=0.35, p<0.01, $R^2$=0.09, p<0.1), indicating that as vegetation cover increases, the amount of soil loss and runoff reduces. However, the soil loss and runoff were depending on the soil texture and rainfall intensity (i. e., $EI_{30}$). The red pepper canopy cover subfactor was more highly correlated with soil loss in clay loam ($R^2$=0.83, p<0.001) than in sandy loam ($R^2$=0.48, p<0.05) and loam ($R^2$=0.43, p<0.1) plots. However, the runoff ratio was effectively mitigated by the canopy coverage under the rainfall only with $EI_{30}$<1000 MJ mm $ha^{-1}hr^{-1}$ ($R^2$=0.34, p<0.05). Therefore, this result suggested that soil loss from the red pepper field could be reduced by adjusting seedling transplanting dates, but it was also affected by the various soil textures and $EI_{30}$.

• Journal of Korean Society of Rural Planning
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• v.4 no.2
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• pp.20-28
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• 1998

A small wastewater collection system for rural area was reviewed and the small diameter gravity (SDG) was thought to be the most appropriate. The pilot-scale field experiment was performed for 15 months and the result is presented. The wastewater used for experiment was the effluent of septic tank in Kon-Kuk University, and components are similar to normal domestic wastewater. The SDG experimental system included 2" PVC pipe and reverse-sloped lower section is included. No clogging problem by solids was experienced at the points where flow direction changed. The pipe-breaking by freezing was experienced during the cold weather, thus proper protection may be required where severe weather is expected.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.279-288
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• 2006

Three different experiments were undertaken to investigate the runoff and erosion loss of diazinon and metolachlor from sloped-field by rainfall. The mobility of two pesticides and which phase they were transported by were examined in adsorption study, the influence of rainfall pattern and slope degree on the pesticide losses were evaluated in simulated rainfall study, and the pesticide losses from soybean field comparing with bare soil were measured in field lysimeter study. Freundlich adsorption parameter (K) ranged $1.6{\sim}2.0$ for metolachlor and $4.0{\sim}5.5$ for diazinon. The K values of pesticides by the desorption method were higher than those ones by the adsorption method. Another parameter (1/n) in Freundlich equation for the pesticides tested ranged $0.96{\sim}1.02$ by desorption method and $0.87{\sim}1.02$ by adsorption method. By the SSLRC's classification for pesticide mobility of diazinon and metolachlor were classified as moderately mobile ($75{\leq}Koc$ <500). Runoff and erosion losses of pesticides by three rainfall scenarios were $0.5{\sim}1.0%$ and $0.1{\sim}0.7%$ for metolachlor and $0.1{\sim}0.6%$ and $0.1{\sim}0.2%$ for diazinon. Distribution of pesticides in soil polite were investigated after the simulated rainfall events. Metolachlor was leached to $10{\sim}15$ cm soil layer and diazinon was leached to $5{\sim}10$ cm soil layer. Losses of each pesticide in the 30% of sloping degree treatment were $0.2{\sim}1.9$ times higher than those ones in the 10% of sloping degree treatment. Pesticide losses from a series of lysimeter plots in sloped land by rainfall ranged $1.0{\sim}3.1%$ for metolachlor and $0.23{\sim}0.50%$ for diazinon, and were $1/3{\sim}2.5$ times to the ones in the simulated rainfall study. The erosion rates of pesticides from soybean-plots were $21{\sim}75%$ lower than the ones from bare soil plots. The peak runoff concentration in soybean-plots and bare soil plots were $1{\sim}9{\mu}gL^{-1}$ and $3{\sim}16{\mu}gL^{-1}$ for diazinon, $7{\sim}31{\mu}gL^{-1}$ and $5{\sim}40{\mu}gL^{-1}$ for metolachlor, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.25-30
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• 1989

A field experiment was carried out to evaluate the effects of zeolite application and vinyl mulching on the changes in soil physico-chemical properties and yield of silage corn on the newly-reclaimed sloped land. Corn (Suweon 19) was cultivated under 4 application levels of zeolite, 0, 500, 1,000 and 1,500 kg/10a, with and without vinyl mulching, and various soil physico-chemical properties and corn growth were investigated. Soil physical properties, such as cation exchange capacity and water stable aggregates, were increased, but soil hardness was decreased by zeolite application. The porosity and temperature of soil were increased greatly by vinyl mulching. The differences between daily maximum and minimum soil temperature were large in beginning stages of crop growth, but those were decreased to $2^{\circ}C$ after mid-August. Zeolite application enhanced the plant growth and increased yields by 3-37% compare to control, also vinyl mulching brought to increase the corn yields by 17-23%. Water stable aggregates was correlated with soil hardness, and silage yields were highly correlated with porosity, air phase and water stable aggregates.