Abstract
The purpose of this study was to evaluate the effect of planting depth (2,4, or 8 cm) on yield and the uptake of N and silicate by rice under low soil fertility in two years. (1) Regardless of the rate of application of basal N (0,3, or 6 gm^<-2>), the numbers of tillers and panicles per unit area were highest at a planting depth of 2 cm and lowest at 8 cm. (2) At 0 and 3 gNm^<-2>, the yield of brown rice tended to reduce as the planting depth increased. At 6 gNm^<-2>, it was highest at a planting depth of 4 cm and lowest at 8 cm. (3) At 0 and 3 gNm^<-2>, the uptake of N and silicate tended to reduce as the planting depth increased. (4) At 6 g m^<-2>, the uptake of N and silicate was highest at a planting depth of 4 cm and lowest at 8 cm. The results suggest that shallow planting increased the spikelet number per unit area (sink) and root mass (source of N and silicate).
