NUTRIENT UPTAKE AND COWPEA PERFORMANCE FOLLOWING EARLY SEASON MAIZE CULTIVATION UNDER DIFFERENT FERTILIZER TYPES

Abstract

Background. The complementary application of organic and inorganic fertilizers has been found to meet soil nutrient deficits, enhance soil physical properties and crop yield. Objective. To evaluate the residual effect of initial application of different fertilizer types on cowpea performance and nutrient uptake. Methodology. A field trial was carried out in the late season between September-November, 2015. Initial fertilizer treatments consisted of poultry manure at 5 t ha-1 + urea (100 kg ha-1), cow dung at 5 t ha-1 + urea (100 kg ha-1), Oyo organic (also known as pace setter fertilizer made in Oyo state, Nigeria) at 5 t ha-1 + urea (100 kg ha-1) and control (No fertilizer application). Three cowpea varieties (Ife brown, Modupe and Ife 98-12) were evaluated on residual plots. Treatments were evaluated in Randomized Complete Block Design (RCBD)(r=4).  Data were collected on growth, yield, chlorophyll content as well as post- planting soil nutrient compositions. Results. All the parameters of the cowpea varieties were better performed on residual plots of poultry manure (5 t ha-1) augmented with urea (100 kg ha-1) for the soil nutrient status, plant uptake and crop yield. Similarly, plant grown on soil previously amended with poultry manure + urea had significant higher chlorophyll contents. Highest grain yield of 4.45 t ha-1 was obtained in the residual plots of poultry manure + urea. Conclusion. Application of poultry manure (5 t ha-1) together with urea (100 kg ha-1) had significant effect on optimum yield of cowpea