The use of agricultural by-products as alternative nutrient sources in crop production had gained popularity in order to reducing the rate of chemical fertilizer application in the field. This study was conducted to determine whether the application of rice milling by-products treated with yeast inoculants could substitute, or reduce the rate of chemical fertilizer application. The results of agronomic measurements showed that the effect of incorporated materials was not immediate, as compared to 100% chemical fertilizer application. However, grain yield and quality was either the same or greater than 100% chemical fertilizer application. It was found out that expanded rice hull (treated with yeast or not) could reduce the rate of applying chemical fertilizers by half. Also, yeast treatment was only favorable only to expanded rice hull and not with rice bran, and was already found to be a potential material in reducing chemical fertilizer application in rice production.

• Pil Dae Seo(Crop Production Laboratory, School of Applied Biosciences, Kyungpook National University)
• John Paolo Nunez(Crop Production Laboratory, School of Applied Biosciences, Kyungpook National University)
• Jae Sang Park(Crop Production Laboratory, School of Applied Biosciences, Kyungpook National University)
• Venecio U. Ultra, Jr.(Univesity of Eastern Philippines)
• Sang Chul Lee(Crop Production Laboratory, School of Applied Biosciences, Kyungpook National University) Corresponding author