Influence of autumn—winter lucerne management and overdrilled ‘Grasslands Tama’ on spring herbage yields under irrigated and dry conditions

Three trials were conducted over two seasons under both irrigated and unirrigated conditions to examine the extent to which available herbage in early spring could be increased by either adjusting the autumn‐winter grazing management of “lucerne alone” or by over‐drilling ‘Grasslands Tama’ ryegrass into lucerne in autumn. Under both irrigated or very dry, unirrigated autumn conditions, spelling ‘Wairau’ lucerne over winter or autumn and winter increased spring yields by a minimum of 34% and 48% respectively. These increases were much greater than the amounts of lucerne foregone by spelling and were entirely in the form of fresh leafy herbage. The results also indicated that the common recommendation to autumn spell and winter graze lucerne is not well founded for the warmer climatic zones where lucerne is able to make some winter growth. Overdrilling Tama into lucerne did not improve spring herbage yields if dry conditions in autumn prevented rapid germination and establishment of the grass. However, with autumn irrigation the overdrilled Tama established quickly and increased spring yields by a minimum of 60%.