Diversified pastures at the front line of climate change in Northland: farmers experiences, new directions and wider implications for other parts of the country

Abstract

The persistence of both perennial ryegrass and white clover is challenged under summer-dry conditions. Future climate change projections indicate greater incidence and severity of summer moisture stress for many regions in New Zealand, and therefore, greater pressure on our traditional pasture base. The ‘Northland Diversified Forages Project’ aimed to identify alternative pasture species that provide an advantage in terms of dry matter yield, quality and/or timing of growth within a summer-dry environment, with a particular focus on legumes. A series of mown-plot trial and paddock demonstrations were established across a range of soil types to assess the potential of a wide variety of forage species. Perennial ryegrass and white clover both failed to persist, comprising less than 25% of the sward within 3 years of establishment. Cocksfoot demonstrated potential as a more persistent alternative to perennial ryegrass. However, whilst a range of legumes were successful at increasing the proportion of legume in the sward and total yield in the first year, significant challenges were identified in maintaining functional legumes across multiple years. This raises questions around whether we currently have the right species in New Zealand to adapt to a changing climate.

The contribution of perennial ryegrass (Lolium perenne L.) breeding to whole pasture productivity under dairy cattle grazing in New Zealand. 1. Variation in yield, nutritive value and persistence‐related traits

“…This confirms farmer feedback (e.g. McCahon et al, 2021; Reynolds, 2013; Rijswijk & Brazendale, 2016), and evidence from research trials (Lee et al, 2017), that even when infected with endophytes offering the best available protection from insect pest damage, perennial ryegrass does not persist beyond 3–4 years under some situations in the upper North Island.…”

“…However, of concern here is the observation from Table6, and the data (not presented) collected in years 4 and 5 from Trial 2 in Waikato, that no cultivar-endophyte combinations remained dominant in the pasture after 3-5 years post-sowing. This confirms farmer feedback (e.g McCahon et al, 2021;Reynolds, 2013;Rijswijk & Brazendale, 2016),. and evidence from research trials (Lee…”

Improving Human Diets and Welfare through Using Herbivore-Based Foods: 1. Human and Animal Perspectives

“…Associated with negative impacts of warmer, drier climate on pasture growth rates, the longevity of the traditional perennial ryegrass-white clover pasture type is also expected to decline resulting in higher rates of pasture replacement [156]. Indeed, the latter impact is already evident across the upper North Island of New Zealand [157] bringing higher costs of production but, importantly, also increased risk of nitrate leaching [158] and high rates of loss of soil C [159]. Adaptation will be required but the R&D response is lagging as pasture research now sits well down the list of Government and industry stakeholder priorities [160].…”

Organising Committee Chair's address: Resilient pastures

“…Resilient Pastures -Grassland Research and Practice Series 17: 7-14 (2021) that resilience to extreme climatic events is paramount (Cullen et al 2021). Farmers in affected areas, especially in Northland, are responding by moving away from perennial ryegrass (Glassey et al 2021;Jagger 2021;McCahon et al 2021). Simple conceptual models such as depicted in Figure 1 help guide the direction of change, but much better definition of what constitutes 'low' or 'high' stress, 'suited' or 'unsuited', 'alternative management' and 'better adapted' is needed to help decision-making at the individual farm level.…”