Modified weeding machine effects to rice growth, yield, and competition to weeds in an organic farming, Northeastern of Japan

Abstract The development of weeding methods is important to support organic rice farming success. Most of organic rice farmer in Japan choose mechanical rotary weeder to remove weeds. Moreover, intra row-weeds remains a big problem in rice fields. The idea was attaching chain in a rotary weeder machine, to remove intra row-weeds during weeding time. This study aims to examine the effects of chained-machine weeding to the growth of weeds and rice yield in the harvest time. Hypothetically, more weeds would be removed, and rice yield would increase. To test the hypothesis, a field experiment was carried out in one organic rice plot in Yamagata, Japan. The treatment was non weeding plot as control/non-weeding (NW); machine weeding (M); and chained-machine weeding (M + C) with four replications each treatment. The result showed us that the addition of chain on the weeding machine not significantly performed higher yield compared to machine weeding. Both M + C and M treatments significantly suppressed weeds biomass and density compared to non-weeding. The decrement for weeds density was up to 90% for both treatments, while M + C suppressed 10% more weeds biomass compared to M. Our study concluded, the addition of chain in the machine weeding remove intra-row weeds but was not affect significantly to the rice yield.