A Rising Disquiet Among the Bogs; Environmental Worries Block Plan by New Jersey Farmers To Expand Cranberry Fields
35 families who work cranberry bogs of New Jersey's pinelands want to expand their 3,800 acres of fields into adjacent wetlands--including portions of Pine Barrens; proposal has support of state environmental officials and some state conservation groups, but it is oppposed by Federal environmental agencies and national environmental groups, who fear that loss of wetlands to agriculture will damage sensitive ecology of state's pinelands; New Jersey is third-largest cranberry producer in world; photo (M)