Compute the solution of the given Question

Question- A wheat field in Central Alberta receives solar irradiance of 225 W/m² on a sunny summer day. Assuming that solar radiation penetrates 1cm into the soil and the soil heats evenly through this depth, and that this field is clay soil (unsaturated).

Part 1- What rate does the soil warm (assuming no downward flux of energy)?

I need help to determine the rate does the soil warm and Answer should be in Kelvin per hour.