Changing roles for legumes in Mediterranean agriculture: developments from an Australian perspective

Pulse and pasture legumes have maintained productivity in Mediterranean agricultural systems since antiquity, providing biologically fixed nitrogen and helping to control pests, diseases and weeds, Throughout the last 500 years many species from the Mediterranean basin have been transferred either accidentally or deliberately to the new-world, and integrated into a multitude of farming systems. During the past 30 years biological, economic and environmental forces have caused failure/breakdown of some of these productive systems. This paper examines the factors influencing legume usage in Mediterranean agriculture and uses the changing focus on legumes in southern Australia to illustrate new roles for legumes in evolving farming systems. An essential factor in developing new roles for legumes is the matching of root-nodule bacteria to both legume hosts and soil conditions. New roles for annual and perennial pastures in Mediterranean-type agriculture are discussed in relation to an analysis of the role of root-nodule bacteria in maximising productivity in these systems. (C) 2000 Elsevier Science B.V. All rights reserved.