Effect of Tillage Systems and Tithonia diversifolia Mulch on Soil Physical and Chemical Properties, Growth and Cocoyam Yield in a Tropical Alfisol

Field experiments were carried out during 2012 and 2013 cropping seasons on an Alfisol (Oxic Tropuldalf) at Owo in the forest – savanna transition zone of southwest Nigeria to evaluate the effect of different ti llage systems (zero tillage (ZT), ploughing plus harrowing (P+H) and ploughing plus harrowing twice (P+2H), and with or without Tithonia diversifolia mulch (TM) on soil properties, growth and yield of cocoyam. The experiment was laid out in a randomized co mplete block design in a factorial combination of six treatments that were replicated three times. Among the tillage systems, zero tillage had the highest soil moisture content (12.3%), lowest soil temperature (31.8 ° C) and lower soil bulk density (1.36 Mg m - 3 ) and higher total porosity (48.7%) that was similar to P+H. ZT also produced the best values of soil chemical properties, growth and yield of coco yam compared with P+H and P+2H. P+2H had the highest soil bulk density (1.56 Mg m