Hedgerow intercropping. Hedgerow of Laucaena leucocephala (Leguminosae) and maize as a companion crop in a field at Wenchi. Leucaena fixes nitrogen. - - Support to national agro-forestry programme in Ghana: GHA/88/007. This project assisted by the UNDP/Food and Agriculture Organisation (FAO) operates various demonstration plots where farmers are taught new or improved agricultural techniques such as the use of Leucaena leucocephala intercropped with food crops where the