101 Questions answered
Deep Ripping Clay Loams: Limited Benefits, Potential Risks, Test First
Generally, crop responses to deep ripping decrease as clay content increases. Deep sands and loamy sands tend to have a reliable response. Clay loams are less likely, but the only way to know for sure is to check with a test rip.
Let’s assume you mean a clay loam texture throughout the root zone. Most of the research suggests a response will be small (if any) or at least unpredictable.
The quality of the subsoil plays a substantial role in the response, as ripping heavier soils can bring big clods to the surface, creating other problems. If the subsoil is dispersive and you bring this to the surface, you run the risk of creating seedbed and trafficability problems in the future, which can even lead to a yield penalty in the short term. Consider applying gypsum and doing a shallower rip (above the subsoil) to get gypsum deeper into the soil to treat dispersion, but weigh up the costs.
If the subsoil has any other chemical issues, like salinity, a very high pH or toxic concentrations of boron, you also risk bringing this to the surface in clods. Subsoil issues tend to increase with depth, i.e. the deeper you go, the worse they get. Ripping can bring up clods of this hostile soil to the surface and make the paddock lumpy.
It will help to understand the soil first. Soil tests will show if there are chemical issues that mean the subsoil is better left untouched.
The best way to know for certain is to do a test rip (working at the right moisture conditions – not too dry, not so wet the soil just smears) and see how the soil responds.
