Using new insights in grazing management to buffer the impacts of climatic variability on pasture resilience

Abstract

Pasture is the main source of nutrition for the New Zealand ruminant livestock industry. Changing climatic conditions and relentless intensification are putting the ability of pastures to provide that nutrition under pressure. Recent understanding of the interactions between grazing management and the life cycle of roots, leaves and seedheads of pasture species creates further opportunities to increase pasture resilience. Root production is directly related to, though lagging, leaf production and turnover. Tiller production is modified by temperature and seedhead production. Matching grazing patterns to maximise the production of each of these features is generally impossible at the farm scale. However, matching some of these characteristics on some of the farm can be achievable, and have long-lasting benefits for pasture resilience. Therefore, grazing management practices such as deferred grazing in late spring, summer and autumn may be used both to provide a boost to root and tiller production, and to transfer feed from one grazing period to another. Changing our winter management practices away from intensive daily allocations towards 4-day shifting may also increase early spring production, while reducing summer grazing pressure in droughts will aid pasture productivity and persistence in the long term. These techniques have the potential to ensure that the future nutritional needs of grazing ruminants will continue to be met by grazed pasture.