Chisel plowing in the fall gives you a jump on preparing your fields for spring planting and more. Chiseling incorporates the bulk of the crop residue into the soil to allow the natural processes to break it down, returning the residual nutrients to the soil. It leaves enough residue on the surface to reduce or eliminate wind and water erosion.
Chisel plowing in the spring breaks up the soil, incorporates crop residue, aerates the land and kills early sprouting weeds. In most soils, a follow-up pass with a disk-harrow readies the field for planting seeds.
The parts of a field on which harvesting equipment travels frequently is likely to have compacted soil or a compacted layer that prevents rain from infiltrating and plant roots are unlikely to penetrate. A chisel plow run deeply along these travel routes will break up the compaction and allow the crop to grow evenly across the breadth of the field.
Conventional plowing, disking, planting and harvesting always involves traveling the same direction up and down the field and over time, the soil tends to reflect these linear farming techniques. Chisel plowing a field at an angle, 20 to 30 degrees from the usual direction, eliminates the linear affect and mixes the field's soil evenly.