Assessment of maize and dry bean productivity under different intercrop systems and fertilization regimes.

Abstract

The productivity of different maize-dry bean intercrop systems (single and double rows of dry bean planted between two maize rows at low and high bean population) was assessed in 2006/07-08 seasons at different fertilizer application regimes (unfertilized control, low, adjusted low and optimum). Sole maize and dry bean plots were included as checks and together with the intercrop systems, they constituted the main treatment while the fertilizer regimes constituted the sub treatment. Treatments were arranged as a split plot design with three replications. There was a significant season x fertilizer interaction effect on maize grain and total biomass yields, and a significant season x cropping system interaction on dry bean grain yield. Grain yield for both crops were significantly (P<0.001) higher in 2007/08 with the highest maize grain yield of 2644 kg ha-1 obtained at optimum fertilizer rate. Dry bean grain yield of 875 and 829 kg ha-1 obtained in 2007/08 at optimum and adjusted low fertilizer rates, respectively were comparable. The highest mean grain yield of 2101 kg ha-1 for maize and 728 kg ha-1 for dry bean across the two seasons were obtained in single-bean row intercrop planted at low and high population, respectively. The single dry bean row intercrop system gave the highest productivity based on the total LER values and thus appears the most appropriate for small-scale farmers. Key words: Fertilizer application, food security, intercrop, land equivalent ratio (LER), planting density and seed inoculation.