Appraising White Yam Dioscorea Rotundata Poir Performance And Fertility Status Of An Alfisol Under Yam - Based Intercropping

Abstract Empirical evidence from many parts of the world indicates that intercropping on a long term basis results in depletion of soil fertility and attendant reduced crop yields. Thus the need arises to critically assess changes in nutrient status of soil under intercropping in order to be able to fashion out an adequate fertilizer package involving addition of organic andor inorganic fertilizers to replenish the lost nutrients hence making intercropping sustainable. To partly meet the need a two year study was designed to evaluate the influence of yam based intercropping on changes in fertility status of an Alfisol tuber yield and yield components of white yam Dioscorea rotundata Poir. The experiment was carried out at the Teaching and Research Farm of the Ekiti State University Ado Ekiti Ekiti State Nigeria during 2012 and 2013 cropping seasons. The experiment was laid out in a randomized complete block design with three replications. The yam based intercropping included sole cropped yam SCY which served as the control yamcowpea YC yammaize YM yamcassava YCa and yammaizecassava YMCa. The results obtained indicated existence of significant P 0.05 differences among the yam based intercropping systems as regards their effects on chemical properties of Alfisol and yam tuber yield and yield components. At the end of 2012 cropping season yam based intercropping resulted in significant P 0.05 decreases in soil organic carbon SOC from 0.68 g kg-1 for SCY to 0.58 0.52 0.46 and 0.39 g kg-1 for YC YMYCa and YMCa respectively. Similarly at the end of 2013 cropping season yam based intercropping resulted in significant decreases in SOC from 0.64 g kg-1 for SCY to 0.550.48 0.42 and 0.35 g kg-1 for YC YM YCa and YMCa respectively. At the end of 2012 cropping season yam based intercropping significantly decreased total nitrogen from 0.50 g kg-1 for SCY to 0.55 0.38 0.44and 0.32 g kg-1 for YC YM YCa and YMCa respectively. At the end of 2013 cropping season yam based intercropping significantly decreased total nitrogen from 0.47 g kg-1 for SCY to 0.52 0.34 0.40 and 0.27 g kg-1 for the respective YC YM YCa and YMCa. Across the two years of experimentation mean values of yam tuber yield adduced to yam based intercropping systems were 7.00 7.16 5.94 5.46 and 4.12 t ha-1 for the respective SCY YC YM YCa and YMCa