Cereal and oil seed crops response to organic nitrogen when grown in rotation with annual aerial-seeded pasture legumes

Authors

Angelo Loi, Department of Primary Industries and Regional Development, Western AustraliaFollow
Dean Thomas, CSIRO
Ronald J. Yates, Department of Primary Industries and Regional Development, Western AustraliaFollow
Robert J. Harrison, Department of Primary Industries and Regional Development, Western AustraliaFollow
Mario F. D'Antuono, Department of Primary Industries and Regional DevelopmentFollow
Giovanni A. Re, National Research Council, Institute for the Animal Production System in Mediterranean Environment, Italy
Hayley C. Norman, CSIROFollow
John Gregory Howieson, Murdoch UniversityFollow

Document Type

Article

Publication Date

6-29-2022

Journal Title

The Journal of Agricultural Science

ISSN

0021-8596 eISSN: 1469-5146

Keywords

Biserrula, dryland pasture legume systems, ley farming systems, nitrogen fixation, serradella, summer sowing, Trifolium

Disciplines

Agronomy and Crop Sciences

Abstract

Nitrogen fixation from pasture legumes is a fundamental process that contributes to the profitability and sustainability of dryland agricultural systems. The aim of this research was to determine whether well-managed pastures, based on aerial-seeding pasture legumes, could partially or wholly meet the nitrogen (N) requirements of subsequent grain crops in an annual rotation. Fifteen experiments were conducted in Western Australia with wheat, barley or canola crops grown in a rotation that included the pasture legume species French serradella (Ornithopus sativus), biserrula (Biserrula pelecinus), bladder clover (Trifolium spumosum), annual medics (Medicago spp.) and the non-aerial seeded subterranean clover (Trifolium subterraneum). After the pasture phase, five rates of inorganic N fertilizer (Urea, applied at 0, 23, 46, 69 and 92 kg/ha) were applied to subsequent cereal and oil seed crops. The yields of wheat grown after serradella, biserrula and bladder clover, without the use of applied N fertilizer, were consistent with the target yields for growing conditions of the trials (2.3 to 5.4 t/ha). Crop yields after phases of these pasture legume species were similar or higher than those following subterranean clover or annual medics. The results of this study suggest a single season of a legume-dominant pasture may provide sufficient organic N in the soil to grow at least one crop, without the need for inorganic N fertilizer application. This has implications for reducing inorganic N requirements and the carbon footprint of cropping in dryland agricultural systems.

Recommended Citation

Loi A, Thomas DT, Yates RJ, et al. Cereal and oil seed crops response to organic nitrogen when grown in rotation with annual aerial-seeded pasture legumes. The Journal of Agricultural Science. 2022;160(3-4):207-219. doi:10.1017/S0021859622000326