Building more resilient pastures for a changing climate
This is day 5 of our seven-day series, The Future-Proof Dairy, where we explore the ideas, technology and changing approaches that could help shape the future of New Zealand dairy farming.
For decades, perennial ryegrass has been at the heart of pasture-based dairy farming in New Zealand.
It has earned its place for good reason. Ryegrass can produce well, responds strongly to fertility and management, and has become deeply embedded in the knowledge, systems and expectations of New Zealand dairy farmers.
But farming conditions are changing.
Longer periods of dry weather, hotter summers, unpredictable rainfall and increasing pressure to make better use of nutrients are prompting farmers to look more closely at what is growing beneath the cows' feet.
The question is not whether ryegrass still has a place.
It is whether a pasture made up of more than ryegrass could provide greater resilience when conditions become difficult.
This is where diverse pasture systems, including species such as plantain and chicory, are attracting attention.
These plants are not new to farming, and they are certainly not a magic solution to every pasture challenge. But they offer different characteristics that may become increasingly valuable as farmers look for ways to maintain pasture quality, animal performance and soil function through more challenging seasons.
Future-proofing the pasture may ultimately be less about finding one perfect plant and more about creating a pasture system with enough diversity to keep functioning when conditions change.
Why pasture diversity matters
A pasture is more than a green carpet for cows to graze.
It is a living system made up of plants, roots, soil organisms, nutrients, water and the animals that depend on it.
Different plant species have different growth patterns, rooting structures and responses to weather.
That means a mixed pasture can behave differently from a pasture dominated by a single species.
One plant may perform strongly during spring while another becomes more valuable as conditions become drier. One may have a deeper root system capable of accessing moisture further down the soil profile, while another may respond quickly when rainfall returns.
This does not automatically mean a diverse pasture will outperform ryegrass in every situation.
Instead, diversity can provide another layer of resilience.
The future of pasture may not be about finding a plant that can handle everything. It may be about growing several plants that each bring something different to the system.
For dairy farmers, that difference could become increasingly important as seasonal conditions become harder to predict.
Plantain brings a different set of strengths
Plantain has become increasingly familiar in New Zealand dairy systems, particularly because of its potential role in nutrient management and pasture diversity.
It has a different growth habit from ryegrass and can perform well during periods when some traditional pasture species may struggle.
One of the characteristics that makes plantain particularly interesting is its ability to take up nutrients efficiently.
Plantain can absorb nitrogen from the soil and has been investigated for its potential to influence nitrogen cycling within pasture systems.
Its presence can also contribute to pasture diversity, creating a sward in which different plants occupy slightly different niches.
For farmers, however, the practical question is always whether a plant performs effectively within the particular farm system.
A pasture species may have impressive characteristics on paper, but if it does not establish well, persist under the grazing pressure or fit the farm's management system, those characteristics mean little.
Plantain needs to be considered as part of the whole pasture strategy.
Its performance will be influenced by soil type, fertility, rainfall, grazing management and the other species growing alongside it.
That is one reason why pasture diversity requires more than simply adding another seed to the mix.
It requires an understanding of how the plants interact and how the pasture will be managed over time.
Chicory and the summer challenge
Chicory is another pasture plant that has attracted interest for its ability to provide high-quality feed during warmer periods.
Its deep root system allows it to access moisture further down the soil profile than some shallow-rooted species.
That can become particularly valuable during dry conditions.
When rainfall disappears and the soil surface begins to dry out, plants with deeper roots may continue accessing water that is unavailable to shallower-rooted plants.
Chicory can therefore provide useful summer growth in suitable conditions.
It also produces highly nutritious forage, making it an attractive option for farmers looking to maintain feed quality when pasture growth is under pressure.
However, chicory is not a replacement for good pasture management.
It has its own establishment requirements and management considerations, and its persistence can vary depending on the farming system.
The lesson is not that every dairy farm should suddenly move towards a chicory-based pasture system.
It is that farmers have more options than they once did when considering how to build summer feed resilience.
Going deeper underground
Perhaps one of the most important differences between pasture species is something farmers cannot easily see.
The root system.
Much of the conversation about pasture focuses on what is visible above the ground. Farmers measure pasture height, assess covers and look at the quality of the feed cows are eating.
But beneath the soil, different plants can have dramatically different root structures.
Some develop extensive root systems that reach deeper into the soil profile.
Those roots can influence how plants access water and nutrients and how the plant responds when conditions become challenging.
Deep-rooted species may be particularly useful during dry periods because they can potentially continue accessing moisture after the upper layers of soil have dried.
Roots also contribute organic matter to the soil and interact with the biological processes taking place beneath the pasture.
This is one reason pasture diversity should not be viewed solely as a feed-quality decision.
It can also be a soil-management decision.
A pasture containing plants with different root structures may explore more of the soil profile than a pasture dominated by one species.
That does not mean every diverse pasture will automatically improve soil health or drought resilience.
Farm management, soil type, fertility, drainage and climate all matter.
But understanding what is happening below ground gives farmers another way to think about pasture performance.
Making better use of nitrogen
Nitrogen is essential for pasture growth, but it also requires careful management.
Farmers need enough available nitrogen to support productive pasture, while ensuring nutrients are used efficiently and losses are minimised.
Different pasture plants can interact with nitrogen in different ways.
Plantain, in particular, has attracted attention because of research into its influence on nitrogen cycling and urinary nitrogen concentrations.
The relationship is complex, and pasture composition is only one part of the wider farm nitrogen picture.
Stocking rate, fertiliser use, soil conditions, animal diet, irrigation, rainfall and grazing management all contribute.
That means planting plantain is not a substitute for good nutrient management.
Instead, it may become one tool within a broader approach.
The future of dairy farming is likely to involve increasingly careful consideration of how nutrients move through the farm system.
Pasture species that can contribute to that efficiency may therefore become more valuable.
Future-proof pasture is not simply about growing more grass. It is about making every part of the pasture system work harder and smarter.
Diversity can provide options when weather turns
Every dairy farmer knows that weather can change quickly.
A season can begin with excellent pasture growth and then move into a period where rain disappears and temperatures rise.
That is when pasture composition becomes particularly important.
A farm relying heavily on a species that performs poorly under those conditions may see pasture growth fall rapidly.
A more diverse pasture may respond differently.
That does not mean the diverse pasture will continue growing at the same rate throughout a drought. No pasture can create rain.
What diversity can potentially provide is a broader range of plant responses.
If different species perform under different conditions, the pasture may be better able to maintain useful growth across a wider range of weather.
That can give farmers more options.
It may also reduce the risk of relying too heavily on one plant to carry the entire season.
This is particularly relevant as farmers consider how to prepare for increasingly variable summers.
The goal is not necessarily to eliminate the impact of drought.
It is to make the farm more capable of managing it.
There is no one-size-fits-all pasture
Pasture decisions need to begin with the farm.
A system that performs well on a free-draining Waikato dairy farm may not be suitable for a heavy soil farm in Southland.
Rainfall, soil type, fertility, temperature, grazing pressure and the timing of feed demand all influence which species will perform.
The farm's calving pattern matters too.
A farmer who needs maximum early-spring pasture production has different priorities from someone managing a system with a strong focus on summer milk production.
This is why pasture diversity should not become another farming fashion.
The question is not simply, “Should I plant plantain or chicory?”
The better question is, “What is my pasture currently failing to do, and could another species help solve that problem?”
If the major challenge is summer dry, deep-rooting species may deserve consideration.
If nutrient management is a major focus, species with characteristics that may influence nutrient cycling could be relevant.
If establishment and persistence are the biggest concerns, then the suitability of the species to the farm needs to come first.
Good pasture management begins with identifying the problem.
Only then should the plant be chosen.
Photo by Dianna Malcolm
Managing a diverse pasture takes knowledge
A more diverse pasture can create more resilience, but it can also create more complexity.
Different species grow at different rates.
They may respond differently to grazing, fertility and weather.
That means farmers need to understand how the pasture is changing throughout the season.
A mixed pasture cannot necessarily be managed exactly like a ryegrass-dominant one.
The timing and intensity of grazing can influence which species thrive and which decline.
Farmers may need to monitor pasture composition as well as pasture cover.
This is where good observation remains essential.
Technology can help with pasture measurement and monitoring, but farmers still need to understand what they are seeing.
A pasture that looks excellent in one season may gradually change over several years.
A species that was originally a strong component of the sward may decline, while another becomes more dominant.
Future-proofing therefore requires ongoing management rather than a one-off pasture renovation.
Resilience is about more than drought
It is easy to think of pasture resilience purely in terms of surviving summer drought.
But resilience is broader than that.
It is about the ability of the pasture system to continue providing useful feed as conditions change.
That might mean coping with heat, recovering after dry conditions, making efficient use of rainfall, responding to fertility or maintaining quality at different times of the year.
A resilient pasture should support the cows while also fitting the environmental and financial goals of the farm.
That means farmers may increasingly look at pasture through several lenses at once.
How much feed does it produce? When does it produce it? How well does it persist? How does it respond to dry conditions? How does it fit the grazing system? How does it interact with nutrient management? And perhaps most importantly, does it make the farm more resilient?
There will not always be a simple answer. But asking the questions is an important part of future-proofing.
Photo by Dianna Malcolm
The pasture beneath tomorrow's cows
The dairy cow of the future may be genetically better suited to heat, more efficient with feed and capable of producing with a lower environmental footprint.
But she will still need something to eat.
That makes pasture one of the most important pieces of the future dairy puzzle.
The opportunity may not be to abandon ryegrass.
Ryegrass has proven its value across generations of New Zealand dairy farming and is likely to remain an important pasture species.
Instead, the future may involve using a broader range of plants where they can add genuine value.
Plantain, chicory and other deep-rooting or diverse pasture species could provide farmers with additional tools for managing dry summers, pasture quality and nutrient use.
The right combination will vary from farm to farm.
What matters is that farmers have the opportunity to make pasture decisions based on the challenges they expect to face rather than simply repeating what has always been done.
The pasture system of the future may look familiar from a distance.
But underneath the cows, there could be a much more diverse and carefully managed ecosystem at work.
Future-proofing pasture is not about finding a single plant capable of solving every farming challenge.
It is about understanding how different species behave and considering whether greater diversity could make the pasture system more resilient.
Plantain and chicory offer characteristics that may be valuable for summer growth, deeper rooting, feed quality and nutrient management, but they need to be considered in the context of the individual farm.
Ryegrass is likely to remain an important part of New Zealand dairy farming, but farmers have an increasing range of options when designing pastures for the conditions they expect to face.
The most important step may be to look beneath the surface and ask whether the pasture is prepared not just for the season farmers have today, but for the seasons they may face tomorrow.
Tomorrow in day 6 of our Future-Proof Dairy series, we look at the idea of the circular farm and explore how effluent could become more than something that needs managing, with opportunities around biogas generation and recovering valuable nutrients.