Heavy Duty Compact Model Disc Harrow Trailed behind the tractor and because of its heavy design and weight can effectively break up heavy clods. And when green manure, trash, or other surface growth is cross-disced, the organic matter is effectively buried and mixed with the soil and decays rapidly into humus. The harrow has a strong and sturdy main frame with high-quality steel discs and heavy-duty graded cast iron spools to provide center weight. Optional wheels can be provided for towing on the road.