Effect of lucerne-wheat rotations on the yield and quality of subsequent wheat crops on the Darling Downs, Queensland.

Abstract

In one experiment, on a brown colluvial clay loam derived from basalt and sandstone, wheat grown after three years of grazed lucerne and grass sheep pasture was compared with wheat grown after three years of summer (grain sorghum) or winter (grazing oats) animal cropping. In a second experiment, on a dark brown clay derived from basalt, an eight-year rotation of alternate wheat-grain sorghum was compared with four years of lucerne grown for hay followed by sorghum, wheat, oats, wheat. Wheat yields were increased by growing lucerne on the more fertile soil which had good moisture-holding capacity; lucerne did not increase wheat yields on the less fertile soil. Grain-protein content increased where wheat followed lucerne, particularly on the less fertile soil; flour quality also improved.