Compaction is a major limiting factor to soil health. In pastures, it results in soil layers that are difficult for roots to penetrate and interferes with pasture productivity. When soils are compacted, pore spaces become smaller, reducing the available habitat of microbial-feeding nematodes and microbes. These soil microbes cycle nutrients, and when they are not available, nutrient supply can be limited. Although compaction may be measured in the upper six inches of the soil, compaction at greater depths could have more of an impact on soil physical properties, especially on heavy soils.
Maintaining a healthy pasture should be a major objective of grazing management, but it should also be used as a tool for maintaining acceptable soil physical conditions. Overgrazing increases soil compaction. With limited grazing sources, animals tend to congregate leading to higher risk of soil compaction due to hoof pressure. Compaction is not visible and often goes undetected. Both grazing livestock and agricultural equipment apply pressure on the ground, leading to potential soil compaction issues. Tillage and pasture renovation are difficult to use in continuous grazing or permanent pastures, proving it difficult to improve poor soil physical conditions.
It can be difficult to lengthen the grazing season and retain the water and soil quality functions of perennial pastures due to compaction. However, planting forage brassicas can help combat compaction. Brassicas would consist of turnips, rape, kale, radish, and mustards which have a long history of being used for cover crops and animal forages. A forage radish has a very large taproot. Originally developed for oil production, oilseed radish is similar to the forage radish, but its taproot is stubbier and more branched. It also tends to be more winter hardy than the forage radish. Forage and oilseed radishes can be helpful in no-till operations because their large root systems help retain soil moisture and reduce erosion. They are excellent at breaking up shallow layers of compacted soils, earning them the nickname “biodrills” or “tillage radishes.”
Hybrid crosses such as Vivant, which is classified as a turnip rape cross, can provide an excellent taproot while also giving excellent regrowth to help prolong your grazing window. This tends to be a smaller seed and has also proven to be quite palatable.
We have many brassica options at Missouri Southern Seed. Give us a call and we’ll help you find the right product for you!