Threat of Soil Compaction is High

Parts of our state received between 2 and 4 inches of precipitation in the last week, creating wet and soggy conditions. With spring upon us, farmers are anxious to spread lime, fertilizer, or manure, and get on with field work. Here are a few tips to limit soil compaction:

1. Evaluate the fields on your farm. Some soils will sit wet longer than others due to texture, elevation, slope, and aspect (south facing slopes drying out quicker). Start work in the fields that dry out the quickest.
2. To determine if soil is fit to be on it, do the 'ball test'. Grab a handful of soil and knead it in your hand. If it easily forms a ball, the soil is too wet for traffic, tillage, or planting activities. Make sure to check a few spots in the field, and take some soil from the surface but also from the subsoil. If the soil falls apart when you knead it, it is ready to be on it.
3. When soil conditions are marginal, it is especially important to do whatever you can to avoid excessive damage. To control surface compaction, use flotation tires inflated to the lowest pressure possible to enlarge the footprint. Radial tractor tires should have a slight 'cheek'. Tracks are another option. Do not use road tires inflated to high pressures (e.g. 100 psi) in the field. To limit subsoil compaction, do not exceed 10 T axle loads.
4. Work with your cover crops – they are starting to grow actively now and therefore dry out the soil. Cover crop roots help improve soil aggregation and improve trafficability and workability.
5. Enjoy the benefits of long-term no-tillage. Long-term no-till soil is better drained, has higher organic matter content near the surface, and has a firm matrix interspersed with macropores. All this make no-till soil ready quicker for traffic, and also more resistant of compaction.
6. Watch the forecast. It seems a period of drier weather is coming, so waiting may be the right thing to do. Remember that surface compaction can severely reduce crop yields and soil function in the short run, and that subsoil compaction can cause long-lasting effects that are difficult to remediate.