Working the soil affects the physical properties which in turn dictate root development, ability to take up nutrients and overall plant health
Avoid turning the soil when it is wet The spring time is not aways the best time to improve the soil. Often the soil moisture is very high and this condition might lead to some destruction of soil texture if it is tilled or turned. Therfore, working the soil is best done when soil moisture conditions are such that you can just form a ball in your hand that breaks apart when lightly challenged. Wait several day before tilling if the ball remains hard.