Effect of continuous organic farming on the growth and yield of rice [Japanese]

摘要

The correlation of the growth and yield of rice with the duration of organic farming (compost mixed with straw) was examined in comparison with conventional farming in Yamaguchi city. In organic farming, the plant length of rice was shorter and shoot number per hill was smaller than in conventional farming, but both of these values increased as the duration of organic farming increased. The maximum tiller number was smaller and the panicle number was also smaller in organic farming. However, both the panicle number and panicle length increased as the duration of organic farming increased. The grain-straw ratio and silicic acid content were higher in organic farming than in conventional farming, and increased as the duration of organic farming increased. These results suggest that the growth and yield of rice increased with continuous organic farming, and that the yield increased through the increases of panicle number per hill and grain number per panicle.