Potential of intercropping soybeans (Glycine max (L.) Merrill) and cowpea (Vigna unguiculata L. Walp) with sunflower (Hetianthus annuus L.) in the transition zone of south west Nigeria

Abstract

Field trials were conducted at the Teaching and Research Farm of University of Agriculture, Abeokuta (7° IS' N, 3° 25' E, altitude 144 m above sea level) located in the forest - savanna transition zone of south west Nigeria, to assess the agronomic and economic potentials of intercropping soybeans and cowpea with sunflower at three growth stages (simultaneously (SS) at planting, tenth true leaf stage, V10 and eighteenth true leaf stage, V18) in 2002 and 2003. Land use advantage in terms of land equivalent ratio (LER>1.00) ranged between 1.04 - 1.40 in 2002 and 1.05 - 1.24 in 2003 for the intercropping systems, whilst marginal intercrop compatibility in terms of land equivalent coefficient (LEC>0.25) ranged between 0.29 - 0.48 for sunfflower/soybeans SS, at V10 and V18 in 2002 and sunflower/cowpea SS in 2003. These identified agronomic advantages did not guarantee substantial economic efficiency in terms of monetary equivalent ratio (MER>1.00) for some of the intercropping systems with LER>1.00 and LEC>0.25. Sunflower/cowpea SS in 2002 and sunfflower/soy bean V10 in 2003 recorded small monetary advantage over the most productive sole crop with MER=T.12 and 1.04 and sunflower yield equivalent (1349.2 and 1421.6 kg ha'1), respectively.