The Walpole Youth Lacrosse League  has signed an agreement with selectmen to take over maintenance of Porker Field in exchange for playing privileges there. The league hopes to keep the current field in prime condition and to expand it, since the local lacrosse program has more than 500 participants.  Porker Field is the second to be taken over under the town’s Adopt-a-Field program. The Walpole Youth Football League began maintaining Stone Field  two years ago.