The amount the horses poop while doing work is completely negligible. We did haul a big cart of manure from the stables, like half a ton or so. Yes, manure is

The amount the horses poop while doing work is completely negligible. We did haul a big cart of manure from the stables, like half a ton or so. Yes, manure is a good fertilizer and promotes a good ecosystem of microbes but it needs animals on pasture (an element in good crop rotation) or bringing it from elsewhere to get the kind of quantities needed.