What I find most interesting about the scenario is the affidavit of possession of "M" owning the caption property by will.  The fact that the affidavit shows ownership by "M" under the will (not by any adverse situation) makes me wonder if there was conditional language in the will regarding the subsequent title to "J".  Perhaps something like "should J elect to farm the subject property upon reaching the age of 25".  You did not indicate the timing of the filing of the affidavit, nor the specific language (other than M owning by the will), so it is just speculation on my part.