Abstract
We investigated the spatial variability of rice taste with a variable rate of fertilizer application applied to reduce the spatial variability of grain yield. The amount of grain protein was compared with vegetation growth, vegetation growth index, grain yield and the amount of nitrogen applied at topdressing. Although it was difficult to reduce spatial variability of grain yield, it was possible to maintain grain yield in spite of a reduction in the amount of fertilizer applied when the variable rate fertilizer application section being 15% less than the amount of fertilizer applied at the uniform fertilizer application section. The number of tillers at heading stage, and SPAD value and plant length at ripening stage were correlated with the amount of protein. It was difficult to estimate the influence of fertilizer on a rice taste map because the amount of amylose may have a high correlation with rice taste compared with the amount of protein. When the grade of vegetation growth index is divided into 3 levels, the pattern is very similar to the fertilizer application plan map. The amount of protein at the variable rate fertilizer application section has a partially high correlation with vegetation growth, vegetation growth index, grain yield and amount of nitrogen.
