A 9-row fluted roller type seed drill with $400 \mathrm{~mm}$ ground wheel diameter is used for sowing wheat at $200 \mathrm{~mm}$ row spacing. Each fluted roller discharges $6500 \mathrm{~mm}^{3}$ volume of seeds per revolution. The ratio of ground wheel rpm to fluted roller shaft $\mathrm{rpm}$ is 2: 1 . If the bulk density of wheat is $850 \mathrm{~kg} \mathrm{~m}^{-3}$, the seed rate in $\mathrm{kg} \mathrm{ha}^{-1}$ will be__________________
A 9-row fluted roller type seed drill with $400 \mathrm{~mm}$ ground wheel diameter is used for sowing wheat at $200 \mathrm{~mm}$ row spacing. Each fluted roller discharges $6500 \mathrm{~mm}^{3}$ volume of seeds per revolution. The ratio of ground wheel rpm to fluted roller shaft $\mathrm{rpm}$ is 2: 1 . If the bulk density of wheat is $850 \mathrm{~kg} \mathrm{~m}^{-3}$, the seed rate in $\mathrm{kg} \mathrm{ha}^{-1}$ will be__________________