In the past few decades, bamboo forests have expanded their distributions in Japan. Developing effective use of bamboo biomass resources is warranted. The aims of the present study were to asses effects of bamboo chip mulching on rice production in agrochemical-free rice farming. We conducted a field experiment using 16 experimental paddy fields (30 m2). We established five treatments with three to four replicates each : 1) control, 2) manual weeding, 3) low-volume bamboo chip application (0,5t/10a), 4) medium-volume bamboo chip application (1,0t/10a), and 5) high-volume bamboo chip application (2,0t/10a). Bamboo chips were applied manually to paddy fields soon after rice transplantation. Consequently, number of tillers and SPAD values were greater in the medium- and high-volume bamboo chip application treatments relative to controls. Application of bamboo chips showed no evidence of weed control. Rice yields were 1.7-1.8 times greater in medium- and high-volume bamboo chip treatments relative to controls. Rice grain quality did not differ among treatments. The results from a small-scale tub experiment (0.3m2) generally conform to those of the paddy field experiment except that aquatic weeds were suppresed in the bamboo chip treatments. We discuss potential mechanisms of enhanced rice production under certain amount of bamboo chip application.