On Sundays, the Rev. Carl Nichols preaches at Big Zion AME Zion Church in little Kenansville on North Carolina’s coastal plain. Tuesdays to Fridays, he drives a cargo van on a daily 320-mile circuit along rural roads edged with pine and fields of tobacco, collards and corn. His mission: delivering boxes of food to people who cannot always afford their own. The minister, his wife, two grown daughters and three helpers make up a tiny nonprofit whose food deliveries are part of an experiment that p