Response of Okra to Poultry Manure Application and Tillage in an Ultisol.

ABSTRACT The trial was conducted at the Faculty of Agriculture experimental field at University of Benin, Benin City, Edo State, Nigeria. Three rates of poultry manure (0, 10 and 20 tons/ha) and two tillage methods (Hoe-tillage) and No-tillage replicated four times was fitted in a randomized complete block design (RCBD). Soil samples were taken prior to and after the experiment for analysis. Soil pH, organic carbon, total nitrogen, available phosphorus, potassium, calcium, magnesium, exchangeable acidity, manganese, iron and zinc were analyzed by standard methods of Udo et al., (2009). Moisture Retention was carried out in triplicates using a pressure plate apparatus. All data collected were subjected to analysis of variance using Genstat package and treatment means where separated by Duncan Multiple Range Test. Sole poultry manure and the interaction of poultry manure and tillage significantly enhanced moisture retention of the soil in both first and residual cropping. Tillage significantly increased (p<0.05) on immediate basis; soil total nitrogen, organic carbon, available phosphorus, Ca and Mg. However, on residual basis, tillage reduced organic carbon, total nitrogen, available phosphorus and micronutrients relative to no-tillage. The interaction of tillage and poultry manure at 10 and 20 tons/ ha significantly (p<0.05) influenced pH, total nitrogen and organic carbon, exchangeable acidity, manganese, iron, exchangeable calcium and magnesium, available phosphorus, Potassium and zinc content of the soil. Interaction of tillage and poultry manure at 20 tons/ ha significantly (p<0.05) influenced okra pod yield in both seasons.