Now that row crop harvest is over in Kansas, producers might be considering deep tillage for the purpose of alleviating compaction. Here are a few things to consider:
How deep should the tillage operation occur?
That is best answered by taking a spade or soil probe out in your field and digging a few holes. Ideally, you should dig down to about 18 inches. You are looking for dense layers that are restricting plant roots. If you see “platy” soil structure, which looks like many horizontal layers of soil about ¼ to ½ thick in diameter, look to see if the roots have penetrated through this zone in the soil. If the roots have predominantly penetrated this zone, the layer probably isn’t really root-limiting. If you see a lot of roots that are growing horizontally, or if they appear stubby and gnarled, lacking many root hairs, that can also be a sign that the roots are having trouble making it through this layer.
If you see a dense zone that ends, at say, 8 inches, you’d only want to go about 9 inches deep with the tillage operation. As you double the depth of the tillage operation, you quadruple the power requirement, so going too deep is a waste of time and energy. Also, there is no point in going deeper and potentially damaging the soil profile even further (risks are explained below). Continue reading “Deep Tillage”