Energy efficiency of horses vs tractors

But you still get manure and that should count for some energy even if they are idle.

Another area of this general discussion I don’t believe I have ever seen adequately addressed is soil compaction.  My filelds have had a tractor on them once in the last 35 years for mowing and baling 2 years ago after I got hurt, otherwise all the manure spreading and haying, etc. has been strictly horse powered- not even a pickup truck.  I recently took my 3/4ton out across the field to pick up something and I could feel the divets every where the truck drove.  My understanding is that 90% of compaction takes place on the 1st pass.   Another factor I wonder about is the vibration from the motor as the wheels are rolling over the ground.  Vibration is used to settle concrete and many other things. In my experience  there is a negative economic impact from the extra compaction caused by the use of tractors on land when animal power could just a easily do the job.  I can feel the difference every time I walk across my fields (and the fields of others).  Jay

Compaction is also a problem because we plant so many annuals and not enough perennials  which send down deep roots to help brake up some compaction.

While it is an interesting study, It’s definitely not a good comparison of horses and tractors at all.  To do that properly you would have to compare two completely separate but similar operations, one with only horses, the other only tractors.  Even then it would be hard to totally compare, because the types of operations where horses are most efficient are different than operations where tractors reach their peak efficiency.   And it’s not only about efficiency, it’s about the big picture of the effects ( or lack thereof) on the environment and local farm system.  Of course if you only use horses two hours a week and use the tractors to help grow their feed you would come up with results like this.  I would also guess, as suggested in a previous post, that teamster experience was a big factor.  I’m not quite as familiar with farming as I am logging, but I do know that the difference in efficient use of time between a beginner and an old hand can be quite large.

So, interesting study, but not very realistic conclusions as far as comparing horse and tractor efficiencies.

Here is an article I have posted before on the same subject, it is from Ireland.

Yes it was definitely an interesting read, and I agree that seeing it’s shortcomings can help us clarify our own positions.

To address the efficiency question/point.  Efficiency is strictly a ratio, of input to output.  You can use any values you want to: human hours or horse hours, or you could address other issues such as the inherent inefficiencies of the tractor as a power source, like the fact that with, for example, a 50 HP tractor, you only end up with actually maybe in the 6-10 HP range at the drawbar.  There are many other values you can put into the efficiency ratio, all very interesting studies.