Some effects of the inclusion of leys in a six-course rotation on light land

Abstract

SummaryAn experiment comparing six-course rotations which included 1-, 2- and 3-year leys of pure grass, pure legume and grass/legume mixture is described, and the results from the fifth and sixth phases of the first cycle and first and second phases of the second cycle are discussed.Compared with all-arable cropping, the inclusion of leys increased the yield of barley grown as the second and third crops after the leys were ploughed up, although the difference was less when 58 kg N/ha had been applied. Neither length nor type of ley affected yield in the second crop after ploughing the leys, but in the third crop 2- and 3-year leys led to greater yield than 1-year leys.Only rotations containing 1-year leys were compared with all-arable cropping in the fourth and fifth crops after ley, but some effects of these were still apparent in that both Italian ryegrass and broad red clover leys led to an increased sugar percentage of sugar beet grown as the fourth crop when no nitrogen was applied, and broad red clover leys led to a greater response to nitrogen in barley grown as the fifth crop after ley.