Referring to the fluted roller seed metering mechanism shown in the accompanying diagram, the seed delivery rate is directly proportional to the exposed active roller length $L$. At an exposed length of $20\text{ mm}$, the seed drill applies $80\text{ kg/ha}$. If the exposed length is adjusted to $L = 30\text{ mm}$ with all other operating parameters remaining unchanged, the new seed application rate is ________ $\text{kg/ha}$ (answer in integer).
Answer Key:
120
Step-by-Step Solution & Explanation
For a fluted roller metering mechanism, seed application rate $R$ varies linearly with the exposed length $L$:
$\frac{R_2}{R_1} = \frac{L_2}{L_1}$
Given $R_1 = 80\text{ kg/ha}$, $L_1 = 20\text{ mm}$, and $L_2 = 30\text{ mm}$:
$R_2 = 80 \times \frac{30}{20} = 80 \times 1.5 = 120\text{ kg/ha}$.