Herviyanti, ., Prasetyo, T. B., Ahmad, F., & Saidi, A. (2019). Humic Acid and Water Management to Decrease Ferro (Fe2+) Solution and Increase Productivity of Established New Rice Field. JOURNAL OF TROPICAL SOILS, 17(1), 9–17. https://doi.org/10.5400/jts.2012.v17i1.9-17