poster - International Conference of Agricultural Engineering

Application of Surface Cover and Soil Amendment for Reduction of
Soil Erosion from Sloping Field in Korea
Su-in Lee, Chul-hee Won, Min-hwan Shin, Woon-ji Park,
Yong-hun Choi, Jae-young Shin, Joongdae Choi*
Dept. of Regional Infrastructures Eng., Kangwon National Univ., Chuncheon, 200-701, Korea
*Corresponding author. E-mail: jdchoi@kangwon.ac.kr
Abstract
Runoff from sloping fields in Korea has been blamed for the water quality degradation in
rivers and lakes. No-till is known to be one of the best practices to reduce muddy runoff.
However, no-till practice does not fit well to intensive vegetation farming and other alternative
practices are required in Korea. The objective of the paper was to investigate the effect of
surface mulch materials on the reduction of runoff and sediment from sloping experimental
plots. The mulch materials were made of straw mat, PAM, rice chaff, sawdust, and gypsum.
Three surface cover materials were tested and analyzed under 10 and 20% slopes and 30
mm/h rainfall simulation. Runoff reduced significantly under covered conditions. The average
reduction of runoff under 10 and 20% slopes was 85.6% and 72.0%, respectively. The
average reduction of sediment discharge from mulched plots was 99%. It was concluded that
the cover materials were effective in reducing muddy runoff from sloping fields.
Key words: Muddy runoff, water quality, sloping field, rice straw mat, sediment.
1. Introduction
Muddy runoff from sloping highland fields during heavy storm events has caused serious
water quality problems in rivers and dam lakes that are important to domestic water supply in
Korea. The soil surface of these fields is not well protected either by crop canopy or crop
residues during the storm events in general because of the timing of vegetable cultivation
(Won et al., 2011). Muddy runoff are largely influenced by rainfall amount, intensity and
duration, soil texture, crop, tillage, surface cover, infiltration, slope and slope length, runoff
amount and velocity (Choi, 1997; Choi et al., 2000; Sharpley and Halvorson, 1994). Effective
and economic control of these factors could reduce runoff and soil erosion, resulting in the
reduction of muddy runoff. No-till practice is known to be one of the best BMPs to reduce
muddy runoff. However, no-till practice does not fit well to intensive vegetable farming and
other alternatives that could resemble no-till practice are required in Korea. One of the
alternatives could be rice straw mulch on the soil surface. Shin et al. (2009) tested the effect
of rice straw mat mulch on runoff, infiltration and sediment discharges under a laboratory
rainfall simulation condition. Use of anion PAM and gypsum is also an alternative to reduce
runoff (Flanagan et al., 1997; Choi et al., 2010; Keren and Shainberg, 1981). Use of
phosphogypsum and PAM mixture could contribute to the reduction of soil erosion (Lee et al.,
2001; Jian et al., 2003; Lee et al., 2010). Won et al. (2011) reported that the treatment of rice
straw mat, PAM, sawdust and rice chaff mixtures could reduce soil erosion significantly
compared to control treatment. However, the effect of surface mulch combined with rice
straw mat, PAM and phosphogypsum has not been reported in Korea. The objectve of this
research was to experimentally test the effect of surface mulch combined with rice straw mat
on runoff and soil erosion under laboratory rainfall simulation.
2. Methods
The main experimental system of this research composed of eight soil boxes, two Norton
Ladder-type Rainfall Simulators, and 10% and 20% stands for slope control. The soil boxes