A second generation of annual pasture legumes and their potential for inclusion in Mediterranean-type farming systems

摘要

A second generation of annual pasture legumes and their root-nodule bacteria has been released to agriculture in Mediterranean-type environments. These new species emanate from selection activity focussed upon ‘alternative legumes’. In 1992, in response to changing constraints upon production, a program was initiated which sought species with different ideotypic traits to the traditional annual medics and clovers used in agriculture in southern Australia. Traits sought in the new species were deeper root systems, improved persistence from higher hardseed levels, acid tolerant symbioses, tolerance to pests and diseases and ease of harvesting with conventional cereal harvesters. Several cultivars of species new to Australian agriculture such as biserrula (Biserrula pelecinus), French serradella (Ornithopus sativus), gland clover (Trifolium glanduliferum) and improved varieties of arrowleaf clover (Trifolium vesiculosum) and yellow serradella (Ornithopus compressus) were developed and have had rapid adoption and impact in southern Australian ley- and phase-farming systems. This paper reviews the importance of ley farming for Australian agriculture, the shortcomings of the traditional medics and clovers and the imperatives for a second generation of annual pasture legume species to be developed. In addition to enhancing ley farming, the commercial availability of a second generation of annual pasture legume species has provided a much needed impetus for the development of more flexible and sustainable farming systems.