Effects of Reclaimed Wastewater Irrigation on Paddy Rice Yields and Fertilizer Reduction using the DSSAT Model

• Published in: Journal of The Korean Society of Agricultural Engineers Vol. 53; no. 4
• Main Authors: Jeong, H.S., Seoul National University, Seoul, Republic of Korea, Seong, C.H., Seoul National University, Seoul, Republic of Korea, Jang, T.I., University of Georgia, Athens, GA, USA, Jung, K.W., Seoul National University, Seoul, Republic of Korea, Kang, M.S., Seoul National University, Seoul, Republic of Korea, Park, S.W., Seoul National University, Seoul, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 01.07.2011
• Subjects: AGUAS RESIDUALES; DSSAT; EAU USEE; fertilizer reduction effect; paddy rice yield; WASTEWATER; Wastewater reuse
• ISSN: 1738-3692

The objectives of this study were to assess the rice yields and evaluate fertilizer reduction effect of reclaimed wastewater irrigation in paddy fields using the Decision Support System for Agrotechnology Transfer (DSSAT) v4.5 model. The experimental plots were designed, which was located near the Suwon wastewater treatment plant in Gyeonggi-do, Korea. The rice yield, irrigation amount, irrigation water quality and soil data were monitored and collected between 2006 and 2009. The DSSAT model was calibrated and validated with observed data. The methods that were used to evaluate this model were the root mean square error (RMSE), normalized root mean square error (nRMSE), and index of agreement (d). The values of RMSE, nRMSE, and d ranged from 145 to 789 kg ha-¹, 3.0 to 13.3 %, and 0.90 to 0.95 for the calibration period, respectively and represented from 91 to 538 kg ha-¹, 2.0 to 10.4 %, 0.94 to 0.98 for the validation period, respectively. Overall, this model showed good agreement with observed data of rice yields irrigated with reclaimed wastewater. The fertilizer reduction effect in paddy field of reclaimed wastewater irrigation was assessed about 60 % in 2008 and 40 % in 2009.