Effect of System of Rice Intensification on Water Productivity and NPS Pollution Discharge

Paddy fields comprise the single largest land use in Korea, occupying nearly 60% of arable land, consuming about 56% of the nation's water supply, and discharging a significant amount of agricultural non-point source (NPS) pollution to public waters. Rural water resources conservation, the improvement of irrigation water productivity (IWP) and the reduction of NPS pollution from paddy fields are important issues in Korea. To quantify the issue, a field-size rice-plot study was conducted for 3 years comparing the treatment of a system of rice intensification (SRI) irrigation management and a conventional practice (CT). The SRI reduced the irrigation requirement at field level by 50% compared to the CT. The IWP of the SRI improved by an average of 94% over that of the CT. The average reductions of the NPS pollutants by SRI was 44.4% (BOD), 38.6% (SS), 35.3% (CODMn), 28.3% (CODCr), 23.8% (TN) and 36.3% (TN). The SRI treatment was concluded to have contributed to healthy rice plant growth, improvement of IWP and reduction of agricultural NPS pollution from paddy fields, which could significantly conserve rural water resources and improve water quality in Korea. Copyright © 2016 John Wiley & Sons, Ltd.