LUSAKA, Zambia — In Nkhundye, a farming community in Zambia’s Eastern province, cattle dung from a communal kraal, a traditional livestock enclosure, is being used to produce energy for cooking, to run irrigation pumps, and to meet some electricity needs. The biogas plant is managed by the Nkhundye Community Cooperative, whose members collectively keep some 300 head of cattle. The dung from the animals is fed into a biodigester that produces met…