NPS Pollution Reduction from Alpine Fields using Surface Cover Material and Soil Amendments

We described the effects of straw mat cover and soil amendments on runoff, agricultural non-point source nNPS) pollution and crop yield on sloping alpine fields in Korea. Two sandy loam field plots were prepared. One was a control plot and the other (SPG) was an experimental plot treated with rice straw, polyacrylamide (PAM) and gypsum (rice straw mat (3,300 kg/ha) + PAM (5 kg/ha) + gypsum (1 ton/ha)). Chinese cabbage was cultivated in the plots and seven rainfall-runoff events were monitored during the growing season in 2012. Less runoff and a lower NPS pollution load were measured from the SPG plot, compared to those from the control plot. The SPG plot had 29.4% less runoff and the pollution load was reduced by 86.6% for suspended solids, 34.7% for total nitrogen and 39.1% for total phosphorus. The Chinese cabbage yield at the SPG plot was 39,600 kg/ha, which was about 40% higher than that at the control plot. These results indicated that the SPG treatment could not only reduce runoff and agricultural NPS pollution but also increase crop yield and be a best management practice for sandy loam sloping fields in Korea.