Published online by Cambridge University Press: 09 October 2009
The efficiency of nitrogen fertilizer use is as low as 0·30–0·35 in most agricultural practices due to losses to the natural environment in many ways. Ammonia (NH3) volatilization is important in paddy rice fields. The present study investigated the effect of a surface film-forming material (SFFM) on NH3 volatilization from a paddy rice field, by model estimation using parameters from evaporative pan experiments. The modified Jayaweera–Mikkelsen (J-M) ammonia volatilization model was employed to simulate and elucidate the effect of SFFM in reducing ammonia volatilization from paddy fields. A parameter of kf value in the J–M modified model was introduced to represent the resistance of NH3 volatilization loss from SFFM. The simulated data fitted well with the prediction of the J–M modified model and field observations. The modified J–M model is suitable for screening and verifying the new SFFM, and merits further study.