Improving soil productivity through biochar amendments to soils.

Abstract

Biochar based soil management has not being fully exploited in the tropics. In a greenhouse study, two soil types (sandy loam and silt loam soils) and 6 treatments namely: 3t ha-l Biochar, 120 kg N ha-1, 120 kg N ha-1 + 3t ha-1biochar, 4t C ha-1 cattle manure, 4t C ha-1 cattle manure + 3t ha-1 biochar and control un-amended soil were evaluated for soil productivity. The treatments were replicated 3 times. Maize variety “mamaba” was the test crop. Shoot dry weight ranged from 41 to 45 g pot-l at the sandy loam soil at Ayuom and 28 to 35 g pot-lat the silt loam soil at Kwadaso. Shoot dry weight was significantly (P < 0.001) higher at the sandy loam soil compared to the silt loam soil. Soil pH declined in both soils. Biochar resulted in N recovery of 4 and 5% in maize shoot and root respectively on the sandy loam soil but caused less N recovery at the silt loam soil. The results show that N recovery can be improved by biochar application to sandy loam soil but not silt loam soil suggesting soil textural effect in the effectiveness of biochar application for soil productivity.   Key words: Biochar, nitrogen use efficiency, soil texture.