Soil erosion is a major threat to food security in rural areas of Africa. Field experiments were conducted from 2011 to 2014 in Majulai and
Migambo villages with contrasting climatic conditions in Usambara Mountains, Tanzania. The aim was to investigate the effectiveness of
mulching in reducing soil erosion and restoring soil fertility for productivity of maize (Zea mays) and beans (Phaseolus vulgaris) under
miraba, a unique indigenous soil conservation measure in the area. Soil loss was significantly higher (p < 0·05) under miraba sole than under
miraba with mulching, for example, 35 versus 20 and 13 versus 8 Mg ha1 y1 for Majulai and Migambo villages, respectively, in 2012. Soil
fertility status was significantly higher (p < 0·05) under miraba with Tughutu mulching than under miraba sole, for example, 0·35 versus
0·25% total N, 37 versus 22 mg kg1 P and 0·6 versus 0·2 cmol(+) kg1 K for the Majulai village; and 0·46 versus 0·38 total N, 17·2 versus
10·2 mg kg1 P and 0·50 versus 0·2 cmol(+) kg1 K for the Migambo village. Maize and bean yields (Mg ha1
) were significantly higher
(p < 0·05) under miraba with Tughutu mulching than under miraba sole, 2·0 versus 1·3 for maize and 0·9 versus 0·8 for beans in Majulai;
and 3·8 versus 2·6 for maize and 1·0 versus 0·8 for beans in the Migambo village in 2012. This implies that Tughutu mulching is more
effective in improving crop yield than Tithonia, although both could potentially protect the arable land from degradation caused by water
erosion under miraba.