"katy" wrote
They did a study of the Amish farmers in the southern Michigan and
northern Indiana area and found that for small farms, those under
300 acres, that Belgian horses were more efficient than tractors.
One of the factors was that a horses weight on the soil does not rip
it up like the heavy tread of a tractor.

There is some truth in this. FWIW circa 1968 I used "no-till" to grow corn for
my cattle. Plowing is for weed control, the freeze-thaw cycle naturally
prepares the soil for planting, and plowing is hideously expensive in fuel, time
and wear & tear on machinery. I'd spread rye grass seed on the snow followed by
manure. The manure sank through the snow carrying the seed with it. Come early
spring the rye grew knee high and kept the soil shaded and moist. Then I
poisoned the rye with a non-persistent herbicide and it lodged up into a mat
that allowed me to drive a flotation tired tractor over the very wet soft soil
pulling a light planter. After harvesting the corn in the fall, I'd disk the
stalks into the soil but never plow. Had the same or better yield/acre as
conventional plowing. I'd have loved to farm like the Amish but it would be
impossible to produce enough crops to feed our current non-farming population
today - let alone grow enough corn to make enough ethanol - using horse and
buggy technology. We'd have to force modern Americans off welfare and make them
(gasp) work like illegal aliens just to provide the manpower. Never happen!!