Application of the Surface Cover Materials for Reduction of NPS Pollution from Actual Cultivation

Abstract

Four actual cultivations were prepared and a variety of soybean was cultivated. A H-flume, an automatic water level gauge and an automatic water sampler were installed at the outlet of each plot equipped for the measurement of flow rate and its water quality. The amount of rainfall of the study area in 2013 was measured as 975.6 mm which was much lower than the annual average rainfall of 1,271.8 mm, resulting in less occurrences in rainfall-runoff events. Rainfall-runoff events were occurred three times during the rainfall event of 4~5 July, 23 and 24 August. The characteristics of NPS pollution discharge of the plots and the reduction effect of the selected BMPs were analyzed during these events. The reduction effect of straw mat and soil amendments (Polyacrylamide (PAM) and Gypsum) on runoff ratio ranged between 38.2 and 92.9% (average 71.6%). The NPS pollution load reduced between 27.7 and 95.1% (average 70.0%) by the application of rice straw mat and soil conditioner when compared with that of control plot. Soybean yield (2,133.3 kg/ha) of the straw mat covered plots increased by 14.3% when compared with control (1,866.7 kg/ha). The effect of straw mat on the yield was not economically viable if the material and accompanying labor costs were considered. The data collected and analyzed on different soil textures and crops in this study are expected to be a fundamental reference for the expansion of the results to the application nationwide and the development of NPS pollution management policies.

Application of Surface Cover Materials for Reduction of NPS Pollution on Field‐Scale Experimental Plots

“…Shin et al . (, ) and Won et al () reported that runoff reduction on sand and loamy sand fields by the SPG and similar surface cover treatments was between 29.4 and 81.2% and between 70.9 and 95.1%, respectively. The runoff reduction on sandy loam fields by the SPG and the SM treatments in the present study ranged from 22.0 to 90.9%, and from 37.5 to 68.1%, respectively.…”

“…Thus the differences in runoff quantity mainly contributed to the large reduction in pollutant loads, and proved that runoff control at source must be a key objective in the control of agricultural NPS pollution. Shin et al (2014) and Won et al (2014) reported that the NPS pollution reduction on sand and loamy sand fields by SPG and similar surface cover treatments was between 13.8 and 95.1% and between 28.5 and 79.8%, respectively. The load reduction on sandy loam fields by the SPG and SM treatments in the present study ranged from 27.6 to 95.0%, and from 38.7 to 96.7%, respectively.…”

“…Although the number of monitoring data was not enough to statistically compare the effect of the SM and the SPG treatments and deduce the effect of the PAM and the gypsum, the demonstrated effect of the SM treatment was also more than enough to be considered good practice (like the SPG treatment) for the control of field runoff. Shin et al (2012Shin et al ( , 2014 and Won et al (2014) reported that runoff reduction on sand and loamy sand fields by the SPG and similar surface cover treatments was between 29.4 and 81.2% and between 70.9 and 95.1%, respectively. The runoff reduction on sandy loam fields by the SPG and the SM treatments in the present study ranged from 22.0 to 90.9%, and from 37.5 to 68.1%, respectively.…”