A STUDY OF THE PARTITIONING OF APPLIED NITROGEN BETWEEN MAIZE AND BEANS IN INTERCROPPING

The experiment examined how nitrogen applied to a maize crop was parti tioned when the maize was intercropped with beans. Treatments consiste d of 2, 4 and 6 rows of beans at within-row spacings of 20 or 10 cm so wn between 'maize' rows in which maize was either present or absent. N itrogen was applied at 0, 30, 60, 90 or 120 kg ha(-1). Maize showed a large response to nitrogen and this was little affected by beans. All bean rows in all positions showed some response to nitrogen. The large st response was from the rows closest to the maize, but this response was similar whether these rows were 20, 40 or 60 cm from the maize. Be ans gave a much greater response in the absence of maize, indicating t hat the main factor determining the partitioning of the nitrogen betwe en the two crops was the superior competitive ability of the maize. It is suggested that the approach could be suitable for examining nitrog en partitioning in other non-legume/legume situations.