The experiment fields consisted of five plots as follows; 2, 4, and 8 tonsㆍha⁻¹ citrus skin in combination with starch sludge and pig manure mixing compost (CSSP), 4 tonㆍha⁻¹ fermented pig manure compost (FPMC) treated plot, and untreated control. Plant height and stem diameter were significantly increased by CSSP. Most of all, average tuber weight and tuber yield per plant were significantly increased in 4 and 8 tonsㆍha⁻¹ CSSP plots compared to the other plots. Marketable tuber (＞50 g fresh weight) yield were superior in order of 4 and 8 tonsㆍha⁻¹ CSSP plot, 4 tonsㆍha⁻¹ FPMC plot, and 2 tonsㆍha⁻¹ CSSP plot.