At Advanced Land Management we call it rotovating. Some others call it subsoiling and some call it forestry tilling. It seems to depend on your location on the globe and the industry you are in.
Typically we get odd looks when we start talking about rotovating since it is still somewhat unknown in comparison to other industry services like excavating, logging, and mulching.
Rotovating is sometimes confused with mulching. What is the difference between mulching and rotovating? Mulching is the process of breaking down the organic material above the surface of the soil and rotovating is breaking up what is under the surface. Mulching is to mowing as rotovating is to plowing.
Rotovating is treating the soil horizon below the surface down to a predetermined depth. The purpose of which can be singular or multiple, such as crushing rock, grinding up stumps and roots, or just conditioning extremely stubborn soil. Most ground that we treat with rotovating has had the organic matter above ground treated through mulching.
Rotovating is a big time power game. It takes pretty much all the HP you can throw at it which is why we use such high HP tractors. Soil moisture can make the highest impact on production due to the added weight of the moisture in the soil and the higher amount of friction in the chamber of the rotovator.
We follow the mulching process with the additional step of rotovating to fully incorporate it into the soil. The biggest advantage to this is that it chews, rips and tears through anything that is down below the surface. It grinds stumps and roots into small bits, smashes rocks into pieces, and pulverizes hard chunky clay soils.
There are several ways to control the result of rotovating. In most cases, it is not difficult to make it look good, but the true quality of the product, especially when dealing with organics like stumps and roots, is the size of the resulting material. Once you start working through the soil in the future big chunks and long stringy material will be unearthed if not done correctly. Adding modifications, adjusting speed, changing direction, and proper preparation beforehand is how we mitigate these issues.
Rotovating is not a fast process, but it does provide a very thorough product when done correctly. It can also solve problems that other methods have a much harder time with. The typical speed is around .5-1.5 mph on an 8’ wide 10” deep pass. The density of the soil, compaction, moisture, and other material in the soil like stumps will dictate the speed.
Our primary choice for rotovating is our Fendt 1050 with an FAE SSH/HP. This combination is extremely efficient and allows us to travel quickly from site to site. It puts out 515 horsepower and lets us go up to 20” subsurface, which is deeper than generally needed. In a single pass we generally go to depths of 10-12” in most circumstances. We use this tool along with mulching to complete land clearing and crop removal without the need to burn or haul off the material. We grind up material into small particles and then rotovate it back into the earth as organic matter. This allows the soil to be replenished, improving the health and fertility of the soil.
Sometimes rotovating is the correct tool for the job and sometimes conventional or haul-off methods are still the right tool for the job. We will outline the pros and cons of different methods in a future article.
-The team at Advanced Land Management
LinkedIn: Matt Bostrom