Effect of Albizia zygia and NPK Fertilizer on the Improvement of Soil Fertility on a Humid Alfisol in Southwestern Nigeria

The effect of integrating Albizia zygia and NPK 15-15-15 on soil fertility and maize yield were studied to investigate the effect of Albizia zygia and NPK 15-15-15 on soil properties, growth and yield of maize. The experiment was laid out as a Randomized Complete Block Design (RCBD) with five treatments and three replicates. The experiment was conducted from 2009 to 2011 at the Teaching and Research Farm, Joseph Ayo Babalola University, Ikeji-Arakeji, Nigeria. The treatments were: control (no treatment), Abizia zygia at 5 tons/ha, Albizia zygia + NPK 15-15-15 at 2.5 tons/ha and 125kg/ha respectively, NPK 15-15-15 at 250kg/ha and 0PK at 250 kg/ha of single superphosphate (SSP) and 90 kg/ha of muriate of potash (KCl). Soil was sampled before planting for determination of soil nitrogen conten, phosphorous, potassium, organic matter, soil pH, total soil porosity, Water holding capacity and soil bulk density were determined. Maize yield was determined at end of growing seasons as well as profitability of the treatments were also evaluated. Soil physical properties such as total porosity, water holding capacity, soil organic matter, total exchangeable bases, cations exchange capacity and soil pH were significantly improved by applying Albizia zygia biomass. Maize yields (1.33, 1.93 and 1.33 ton/ha in 2009, 2010 and 2011 planting seasons) were found to have increased significantly in the plot treated with Albizia + NPK 15-15-15 over other treatments. In the same vein, the same treatment (Albizia + NPK 15-15-15) was found to have returned more money (N37, 459 and N76,204 in 2009 and 2010 cropping seasons respectively) to the farmer over other treatments.