成果の概要

On-farm field trials were conducted to demonstrate that the effect of P-dipping on rice growth and grain yield can be further enhanced by combining it with rice genotype with a shallow root system architecture. We successfully set up two field experiments using the P-dipping technique with three rice genotypes with different root architecture. To clarify the underlying mechanism of interaction between rice genotypes with different root systems and the localized P application, 1) we collected soil samples before transplanting and will analyze for the vertical distribution of soil properties in paddy rice soils (top 0 – 30 cm soil layers), and 2) we installed soil solution samplers to analyze the soluble P distribution at different soil depths and 3) we set up bucket colander to analyze the spatial distribution of the rice roots in the different soil departments.