Although it's hard to imagine that an onion farm would produce an odor as unpleasant as most any kind of livestock operation, it is highly likely that it would produce a noticeable odor, which might be especially strong at harvest time. During the process of harvesting onions, the leaves and bulbs are likely to be cut, crushed, pulverized, and shredded, resulting in the release of toxic fumes highly likely to irritate the noses of anyone in the area. People who are especially sensitive to the gas released by the onion plants may even suffer allergic reactions and may be unable to remain in the area for long. However, most people are probably only going to find the smell unpleasant and complain a little about the noxious cloud of aromatic vapor responsible for their suffering. Garlic is another food crop that would also produce an extremely disagreeable odor, but, again, not as unpleasant as that likely to be encountered in close proximity to any kind of operation involving livestock.