Diverse Pastures for ReGen Ag
Massey University investigates pasture species in regen ag
One of the claims of a regenerative agriculture approach to pastoral farming is that diverse pastures with multiple (more than 10) species produce more and better-quality feed than simple mixtures. Whenua Haumanu lead and Professor of Dairy Production Systems, Danny Donaghy, and his team are testing that claim in a seven-year study under the Whenua Haumanu programme at Te Kunenga ki Pūrehuroa Massey University.
Professor Donaghy explains regenerative agriculture (also known as regen ag) has gained popularity in parts of the USA, and Australia that are increasingly been threatened by ‘desertification’. Intense agricultural and monocultural cropping practices have begun to strip the land of its ability to support healthy production, hence the need to ‘literally, regenerate soils’. He says it makes sense in those scenarios where tonnes of topsoil have been lost through intensive cropping practices, to move to a pastoral farming system, where animals become a part of the land management, and a lighter touch can be used to support the productive environment.
In New Zealand, we already have a pastoral farming system with higher levels of soil carbon than many other pastoral soils worldwide – so the questions that need to be asked are, what more can be done to support production in this country? And what impact do regenerative practices have in a New Zealand context?
Professor Donaghy believes New Zealand farmers are becoming increasingly interested in benefits of diverse pastures and alternatives to their current pasture base, mostly driven by climate volatility, and issues with persistence of rye grass and white clover.
While regenerative agriculture is still spoken of as a subset of approaches to pastoral farming (and Professor Donaghy notes there is a lot of research going on around the world in that area), there are many more farmers looking at diversifying their pasture base, without calling themselves Regenerative, or adopting management practices that might be loosely classed as regenerative.
The Whenua Haumanu programme at Te Kunenga ki Pūrehuroa Massey University has been set up to explore a number of aspects of regenerative farming on New Zealand farms. It is uncovering findings and developing practical applications focusing on pasture diversity, regenerative agriculture practices, and measuring their impact on New Zealand pastoral farming systems.
These practices include approaches such as the use of diverse pastures, different grazing techniques, and the application of varying levels of nutrients or other additions to soil. They are monitoring and comparing the impacts of those applications to see which work best under local conditions.
Alongside the regen ag practices, the programme is also testing and measuring the impacts of existing pastoral systems – simpler ryegrass and clover pastures under current best practice grazing and fertiliser management.
So, how does an increase in species diversity and regenerative management affect pasture growth? In 2026 and four years into a seven-year study, Massey University’s Whenua Haumanu programme is confirming what multiple other studies have found - over time, pastoral systems become more grass dominant. And it has found that of the 18 or 19 species initially sown, 11-12 species are still present in the pasture in varying amounts, with about 5 species ‘doing the heavy lifting’ and of those, 3 or 4 species were clearly dominant.
Diverse pastures were sown with a variety of species, including legumes, herbs and grasses. In theory, each species is included to fill a gap and ‘do a job’. Multiple studies have shown that more species diversity improves pasture production by ensuring that at least one or two species always fit the current conditions and therefore annual growth is more stable.
That would suggest that as species disappear from our diverse pasture, annual pasture yields should decrease. However, what was found is that pastures containing 4-5 species are capable of producing as much pasture as those containing the original 18 or 19-species mix. And the 4 or 5 species that have persisted are those that suit the farm site and system the best.
So that raises the question: why would you sow a multi-species mix when many of those species may not suit the conditions they’re being introduced into?
The advice from the Massey team to farmers wanting to increase species is they should take the approach of functional diversity – and not a broad ‘more the merrier’ approach of throwing multiple species in and seeing what comes out. ‘In practical terms, it’s around the idea of diversity being designed by the functions that the farmer wants, rather than just throwing as many seeds into a mix as possible’, says Professor Donaghy.
As he points out, sowing multiple different plant species in a pasture that are not going to persist is a very expensive approach to pasture management. In addition, if it is unclear that certain plants thrive or struggle simply due to climate variation – with very dry summers or wet winters – then that is also not a sustainable approach.
The Massey team began their investigations by asking what is it that farmers are trying to achieve, or what are they trying to overcome? Then, what system are they running (e.g., sheep, dairy, etc.) and what the physical attributes of their location (e.g., soil type, climate) are. By using this approach, species are selected to work alongside each other and help to resolve or mitigate those problems.
And Professor Donaghy adds, it may be as simple as adding a few additional species into an existing ryegrass/white clover base, which is an easy approach for farmers to adopt. Professor Donaghy says traditional approaches will still be relevant, and still practical and doable.
Within the MPI-supported Whenua Haumanu programme there have been around 30 post-graduate students working within the Massey team. Their association with the programme is not only playing a role in gathering important information for farmers, but is also helping to develop the next generation of future farm systems experts.
As a result of this study, a framework is being developed to help farmers decide which species will fit with any given farm system in New Zealand. Farmers will be able to use this resource to help decide what plants are most appropriate for their pastures and avoid sowing plants that will not contribute meaningfully to that system.
Science for Farmers | Whenua Haumanu
https://www.youtube.com/watch?v=46Z5q8idofU&t=3s
Whenua Haumanu – Nurturing the Land through exploring pastoral farming