Managing the Competition in Cereal-Subclover-Systems

Summary

The success of the establishment of living mulch systems in cereals depends, among other factors, on the spacial seed arrangement of the main crop and the associated
crop as well as on the nitrogen availability. A series of experiments with three different types of seed arrangement has been performed in southern Germany and central Italy
in order to assess the role of this factor using model systems with wheat and subterranean clover. The effect of nitrogen availability was tested in a separate experiment with 12 different levels of N fertilization. The best seed arrangement was narrow alternate rows, where competition between crops is reduced in the early growth stages. At higher N fertilization rates, subterranean clover was suppressed; however, at yield levels, typical for organic farming (3-6 t/ha), the establishment of a subclover canopy under wheat is possible.