The challenges facing legumes in a dryland environment - a consultant's view

Abstract

The dryland regions of New Zealand suffer from summer moisture deficits in the majority of years. These dryland regions have been developed along the same basis as other farming regions, with increasing fertiliser usage leading to more subdivision and higher stocking rates. Given the exposure to droughts, the production per head of these regions has been extremely variable. Historically, dryland farming systems have been based around breeding ewe systems with all lambs finished if the season allowed. Since the removal of all Government support during adverse events, in the early 1990s, farm systems have become considerably more diverse. Irrigation areas have doubled between 1985 and 1999 to approximately 500 000 hectares. Both sub clover and lucerne have been used extensively in dryland areas, but the main legume is still white clover. Farmers recognise the significant limitations in the ability of white clovers to cope with summer droughts, but have not been able to efficiently utilise other legumes, which require unique management to perform. There are a number of reasons for this. Looking forward, the five key roles that legumes have in dryland farming systems are, to persist within a general purpose pasture, to produce nitrogen, to improve summer feed quality, to improve year round quality feed through specialist crops and pastures and to provide specialist composite feeds (i.e. condensed tannins). With the increased diversity in farming systems, growers require a more diverse range of legumes from perennial species to annuals that will fit a short-term high feed quality niche.