Abstract
SUMMARY: Maize and cowpea were grown in mixed and pure stands, using the same overall density in all plots. Four fertilizer treatments N0P0, N1P0, N0P1and N1P1were imposed in experiments carried out during the early growing seasons of 1976 and 1977 at Ibadan in the rainforest zone of Nigeria. There was no competition between the crops for nitrogen or phosphorus and yields in mixtures were significantly higher than the means of the species monocultures, as shown by relative yield total (RYT) and C (complementation) values.