It’s dry and we harvested early, so we have time to kill — and diesel is cheap. Sjoerd Duiker, soil management specialist at Penn State, is a graduate of OSU’s School of Environment and Natural Resources and works just next door. A year ago he supplied us with these remarks on when and why to do fall tillage, it bears repeating.
- When compaction has been caused, remedial action may be needed. This is especially the case if ruts have been created. If no ruts are seen it is probably not needed to do tillage — instead plant a cover crop to use the living root system to alleviate compaction.
- Ruts need to be smoothened out to be able to plant the next crop successfully, however. If ruts are uniformly distributed across the whole field, some type of tillage may need to be done on the whole field. In many cases, however, ruts are localized and only need localized repair.
- It will be necessary to till deeper than the depth of compaction. Shallow ‘vertical tillage’ tools that only do tillage in the top 4 inches will not be sufficient to manage soil compaction.
- Very tough shanks are needed that will penetrate instead of bounce on top of the compacted layer. New subsoilers can do maximum fracturing without doing much surface disturbance with straight or bent-leg shanks. Parabolic shanks do much more surface disturbance and will need more secondary tillage for seedbed preparation and are therefore not preferred.
- Deep tillage may be what you could use in the fall, and then come back in the spring to smooth the field up with a field cultivator or disk harrow.
- Deep tillage should fracture the soil and it therefore needs to be performed in relatively dry soil.
- Deep tillage can be performed in a living cover crop in the spring — if you use the modern, low disturbance subsoilers. So let subsoiling not deter you from planting a cover crop.
- The more tillage you do, the more you set yourself up for increased compaction problems in the future.