Six trials were conducted in 1966-68 in which four cereals and two annual ryegrasses were overdrilled into lucerne in the autumn. Cereals were more productive than annual ryegrasses when left uncut until the spring. Nitrogen fertilizer improved the growth of the overdrilled species but also stimulated weed growth where there was inadequate competition from the overdrilled species. To make best use of the productive potential of the overdrilled cereals they should remain ungrazed from sowing until early to mid-spring, but this clearly has to be weighed against other management factors.
