Comparative effects of plant residues and NPK fertilizer on soil properties in a humid ultisol

Abstract

Field experiments were conducted at two locations in 2001 and 2002 on acidic Ultisol of Southeast Nigeria to assess the effects of amending soil with plant residues on soil physical and chemical properties. The soil amendment treatments compared were natural fallow, wood ash at 6 tha^-1, peanut residue at 12 tha^-1, combination of wood ash and peanut residue at 6 tha^-1 and 12 tha^-1 respectively, and NPK fertilizer (300 kg ha^-1). Incorporated wood ash, peanut residue, their combination, and fertilizer increased cation exchange capacity (CEC) compared with fallow, peanut residue increased soil N but not P. Ash increased soil P and not N, NPK fertilizer increased soil N, P and CEC. Ash and peanut residue, alone or combined, reduced soil bulk density and increased aggregate stability and porosity.

Nigerian Journal of Soil Science Vol. 15 2005: 9-13