Suitability of six hedgerow species for alley cropping on an acid infertile soil in Burundi

The suitability of six hedgerow species for alley cropping was assessed on an acid infertile soil in the highlands of Burundi between 1988 and 1993. T he fastest growing species was Sesbania sesban, followed by Calliandra! cal othyrsus and Leucaena diversifolia. The slowest growing were L. leucocephal a and L. collinsii. The growth of Senna spectabilis was intermediate. Sesba nia sp. did not tolerate coppicing and died out in the second year. During the second and third years, crop yields from the alleys were lower than or at best equal to those from the control plots. In the fourth and fifth year s, Calliandra sp. enhanced maize yield by 29-63%, L. diversifolia by 27-43% , and Senna sp. by 24-38%. Maize yields from the L. leucocephala and L. col linsii plots were not significantly different from those of the (no-hedge) plots, which averaged 2.1 t ha(-1) yr(-1). The most effective species in co ntrolling weeds was Calliandra sp. followed by L. diversifolia and Senna sp .