Pasture cultivars in ecological perspective

An overview of the variety in New Zealand bred pasture cultivars is obtained by comparing the group against the variety that has developed in the whole spectrum of herbaceous plants during evolution. This was done by classifying each cultivar into one of seven different ecological groupings termed strategies. Each strategy grouping represents a different mature functional type; the seven groupings collectively cover the full range of mature plant types. This preliminary classification confirmed that there are different ecological strategies in our cultivar range but, as might be expected, they represent only a small part of the full range of ecological options. All cultivars are best suited to moderate grazing and high to medium fertility. The information obtained by viewing pasture cultivars in this wider context is used to predict that further breeding is needed to develop pasture cultivars for extreme situations and for use in mixtures. Stress tolerance associated with a rapid, contracted life-span appears to, be the best option for cultivars for dry or low-fertility pastures. It is also predicted that complex pasture mixtures are likely to be easier to maintain and of more value in lower fertility or moderately droughted pastures than in highly fertile pastures. Opportunities exist to develop additional cultivars suited to the different niches in these pastures. Amalgamation of knowledge from agricultural and non-agricultural research can clearly help solve agricultural problems and is an efficient use of science. Means should be sought to use information from both fields to look at finer-scale questions about cultivars. Keywords plant breeding, strategy theory, low fertility, drought, pasture mixtures, plant competition, niche differentiation, species diversity, science