We own four small ponies/large miniature horses, and you would be amazed by their strength. My largest is 38 inches at the withers -- big enough to be extremely strong, but small enough to be easily handled. I trained him for recreational driving and need to put him to work around our farm. Several friends do farm work with their minis, and one uses theirs for light logging. The challenge lies not with their abilities, but with finding the appropriate size implements and forecarts. While driving harnesses are easy to find, heavy duty work harness takes more searching and knowledge. A good place to start is Patty's Pony Place. Of course, with any work animal of any size, proper care is essential, and the learning curve is steep. Mot typically, people I know already had them decided to train them for farm work, rather than buying them specifically as mini plow horses. The rewards, however, are immense.