A recent correspondent was concerned that horses shared the same pasture as
fallen Pecan nuts.
I have always used organic fertilisers and manures, when available, in
conjunction with others, as the crops needed.
A glance through Organic Gardening books however recommends such manures
for 'Organics' that I'm surprised that many new potatoes aren't 'gift
wrapped'!!
Even these practices seem to engender no noticed health hazards~~ though
I do avoid 'Organic Produce' other than my own. Even their appearance is
off-putting. Eating 'fads' always seem to go OTT.
Best Wishes~~ A good site though some contributors do seem unduly
caustic to those genuinely looking for advice.