Economic efficiency of green maize intercropped with beans grown under Tithonia and inorganic fertilizer

Abstract

A field trial aimed at assessing the performance of maize and beans under intercropped systems was conducted in 2013 under three experimental components of maize, beans and maize-bean intercrop in a randomized complete block design (RCBD) with three replications. Each component was subjected to treatments that included: a control-without fertilizer (WF), mineral fertilizer (MF) at 150 kg/ha of 17:17:17, Tithonia biomass (TDB) at 8 tons/ha and integrated application of MF and TDB comprising 4 tons/ha Tithonia and 100 kg/ha mineral fertilizer (MF/TDB). The MF/TDB produced 21.7% higher green maize yields than control, while MF and TDB produced 8.96 and 7.52% higher yields, respectively than the control. The land equivalent ratios (LER) were higher than one in all the intercropping plots, thus indicating an optimum exploitation of the environmental resources. Control plots showed the highest yield advantage in terms of LER of 1.70. When maize yield was converted to bean equivalent yield (BEY), the intercropping BEY was higher than the BEY in the sole for all fertilizer types, thereby revealing an agronomic advantage. The actual yield loss (AYL) values for maize indicated a yield gain of between 11.2 and 15.05% when MF and MFTDB were used in the intercropping compared to the sole cropping. Beans recorded yield loss in all the fertilizer types except in TDB which had a yield gain of 20.45%. The economic performance of the intercropping systems, affirmed that the most advantageous fertilizer type for maize was MF/TDB with an IA of 6.566. The monetary advantage index (MAI) indicated a definite yield and economic advantage in maize-bean intercrop over their sole cropping, with integrated use of MF/TDB as nutrient sources being the most economical and advantageous fertilizer regime.