Dryland legumes: perspectives and problems

Abstract

The different perspectives or concepts involved in developing legumes for dryland pastoral systems is commented on in relation to: N-fixation versus animal feed; root nodule bacteria requirements; large introduced legume flora compared with indigenous; species niche in relation to environmental gradients of moisture, temperature, fertility, and grazing; species adaptation along the decreasing fertility gradient from fine-root nutrient scavenging grasses, N-fixers, mycorrhiza, and proteoid roots; interaction of N- fixation with soil organic matter; establishment; determinants of pastures legume composition; and the possible role of allelopathy. Key words: dryland, environmental gradients, legumes, N-fixation, pasture composition

Soil pH, exchangeable aluminium and legume yield responses to deep-placed lime at Omarama Station

“…Toxic levels of exchangeable aluminium (Al) occur extensively in the acid soils of the South Island hill and high-country (Moir & Moot 2014;Whitley et al 2016). Al is particularly toxic to legumes which are relied upon in the hill and high-country for nitrogen fixation and quality feed (Scott 2003). Al toxicity impedes root growth, damages root caps and root hairs, inhibits nodulation and reduces the ability of plants to extract water and nutrients from soil (Foy et al 1978).…”