Production efficiency of maize-based cropping system as affected by intercropping date of companion legume crops

Abstract

Choosing appropriate legume crops and timing of their establishment is believed to be a relevant management option to minimize intercrop competition effects on the main crop. A field study was conducted at the experimental site of the Assosa Research Centre, located in western Ethiopia, to determine the production efficiency of maize-based cropping system under different interseeding dates of companion legume crops. The experiment was laid out in two factors randomized complete block design (RCBD) replicated three times. The factors employed were four legume crops namely, cowpea (Vigna unguiculata), soybean (Glycine max) and two common bean (Phaseolus vulgaris) varieties (Black Dessie and Awash Melka) intercropped with maize (Zea mays) at three times [simultaneous, four and eight weeks after maize emergence (WAME)] plus sole stand of the respective species. Significant (p≤0.01) effect of legume crops was observed on the total grain yield of the maize, where maize association with Black Dessie variety yielded the highest grain harvest (2.813 t ha^-1). The effect of intercropping time was, however, non-significant on total grain yield. Computation of the intercrop efficiency revealed that maize and Black Dessie variety complemented each other under intercropping simultaneously and four weeks after maize emergence, indicating that they were not competing for exactly the same ecological niches. Generally, the agronomic measurements and computations of intercrop efficiency affirmed that simultaneous intercropping of maize with Black Dessie variety was remunerative. The economic evaluation, on the other hand, indicated that the net benefit was higher for maize-soybean intercropped simultaneously. This economic performance was not affected under the worst possible input and output price scenarios as shown by the highest marginal rate of return. Hence, farmers stand to gain better when they intercrop maize with soybean or Black Dessie variety than the maize alone.

Key words/phrases: Actual yield loss, Intercrop efficiency, Interseeding, Marginal rate of return, Partial budgeting.