When one plows somebody else's
field, and the other one does not protest, is this indicative of the
presumptive ownership of the one who plows?
Some say “yes,” because a man would not see another plow his land and
remain silent. Some say “no,” because the owner may be saying to
himself that the more the occupant plows, the softer the soil becomes
and the better crop he, the owner, will be able to produce from the
fields when he returns to it.
Rav Ashi said, “I asked all the great scholars of the generation, and
they said to me that plowing establishes chazakah.” Rav Nachman bar
Yitzhak answered, “Is it proper to rule based on a poll? There are
others who don't think this way.” And the final decision is that
plowing does not establish chazakah.