“Nitrogen Nutrition of Some Local Rice Varieties Grown Without Fertilizer on Acid Sulphate Soil Area in South Kalimantan”. JOURNAL OF TROPICAL SOILS 14, no. 1 (January 1, 2009): 41–47. Accessed December 26, 2025. https://journal.unila.ac.id/index.php/tropicalsoil/article/view/15.