White clover performance in sown pastures: A biological/ecological perspective

Abstract

Recent advances in farming systems, have prompted a re-appraisal of the performance of white clover in New Zealand pastoral agriculture, in response to the question, is white clover delivering? Using recently developed insights into the processes by which our main pasture species, ryegrass and white clover, grow, this paper will briefly examine the establishment of white clover in mixed pastures and the ecological and biological premises of the two main functions of white clover in pastoral ecosystems, which are to 1), support the N economy of pastures via N fixation and 2), provide high quality livestock feed. The impacts of management decisions and environmental conditions are re-interpreted, in order to evaluate realistically (biologically) what our expectations should be. White clover is still able to deliver on function 1, but may not meet expectations in all cases on function 2. Keywords: ecology, environmental impacts, grazing management, herbage quality, light, mixed pastures, N economy, N fixation, plants, populations, ryegrass, white clover