ISUWAN, A. and KEAWARAM, T. 2021. Effects of Fertilization Regimes on Grain Yields and Economic Returns of Pathum Thani 1 Rice Grown on Sapphaya Soil Series. Walailak Journal of Science and Technology (WJST). 18, 2 (Jan. 2021), Article 6838 (7 pages). DOI:https://doi.org/10.48048/wjst.2021.6838.