Robin Oakley, Canterbury

Fifth generation farmer, Robin Oakley, has been growing vegetables in Canterbury since he was a kid and now supplies supermarkets around the country. His family is committed to sustainable farming and is starting to think about what that means for the climate.

Learn how Robin Oakley is managing greenhouse gas emissions on his Canterbury vegetable farm.


Duration: 6:57


From a young age, I've been quite passionate about growing vegetables. Putting a seed in the ground and seeing it grow and dealing with weeds and bringing something through to harvest. And then sitting at the dinner table at night knowing you're eating something that you've grown. It's a pretty rewarding feeling.

Oakley’s Premium Fresh Vegetables is currently growing on around 450 hectares of owned and leased land. We’re supplying potatoes, broccoli, beetroot 52 weeks of the year to largely supermarket customers. And we've got pumpkin that we grow, which is seasonal supply from April through to November.

Environment is a big issue nowadays and I think maybe it's caught up with everyone, that for a long time everyone just did what they did. And now we're seeing this consequence - global climate change.

It's real. It's happening. It's our backyard. And one can question at what rate it's happening and what effect it's going to have. But I think the bottom line is it's real, it’s happening. It is going to have an effect, and we've all got to get on board and do our bit.

The two that certainly got brought to our attention is the nitrate leaching and nitrous oxide gases.

So, in regards to what we're doing about it, we're using Overseer to measure what's actually going on, and that's given us a number. So, then we can see where we’re at. And with that, we can look at what things we can do, or where we think we can improve or reduce what we're currently doing.

And we're doing things on farm, such as e-mapping paddocks to determine where the variances are in the paddock for crop nutrition.

We are doing even more soil testing than what we've been doing in the past with measuring paddocks before we start with the crop. And then we're also measuring what we've got left in the paddock afterwards so we can put a number on that.

We are using moisture probes so we're quite accurately monitoring what's actually happening in the soil with irrigation or rain events and that gives us the ability to better predict what to put on and when. So we can avoid overwatering at any time and we can also avoid the plant going into stress,

We’re also doing plant tests as well, to see what's actually in the plant and we’re forming more of a database to understand what levels we need to be at to get a good outcome with the crop.

A big part of it’s fine tuning, we've found with what we've done that we’re, we're pretty close to where we need to be, but we can always do better, and having these measurements allows us to do better and also, at the end of the day helps take a bit of risk out of the business, because you're more certain that you are putting the right amount on. You haven't put on too much / not enough. And that goes with fertilizer and with water.

Crop rotation plays a big part, in the impact you have with the environment. And you observe over time that some crops naturally do better after others. And it's about finding what that best sequence is and also one of the other things we're doing now, is we're doing more cover crops than what we did in the past. So, we're moving and sooner afterwards, the assumption being that if there's any free nitrogen left in the ground that you get in there and get that soaked up in a cover crop and then that can return back into the soil and come back again for the next crop. So, there’s less chance of leaching.

Another thing we're doing is we've changed our practices quite a bit on soil cultivation. So we used to plow nearly all our ground and we hardly plow any ground at all now. So the cultivation we are doing is with rippers and discs.

So increased soil structure and organic matter going back into the ground gives you more holding capacity for both nitrogen and water. So anywhere we can help build that soil structure up by less cultivation and more organic matter going in, I think is a key part.

But the underlying thing is you can't manage what you can't measure.

So it's about measuring to start with. And then you can start to look at the numbers and go, right, well, what if we do this or what if we do that and try and understand the things that you could be doing or only making some small changes in your business, the impacts that that could have.

And in the big picture, I think everyone's business is bound to have some room to reduce and improve. And that's what our goal is.

In terms of the compliance that's certainly coming our way, I've found a big part is finding the right consultant to work with. You give them the information, they can digest it and bring it back to you on a report and say, here's what's going on, and then start understanding and working with them and going, well, that's not hard.

It's you know, at the end of the day, we're all caretakers of the land with what we're doing.

We're all trying to get the best out of our farms and no one's looking after them more than the farmers themselves because, you know, how we look after them is how they're going to look after us.

So it's just an extension of that and it's just understanding it's another tool and another way of measuring and achieving that outcome.

We're providing fresh vegetables to a lot of consumers in New Zealand, and we've got to be ready for when they come back and ask the question, how much impact are you having on the environment?

And I think we've got to be able to give an honest answer and back it up with facts to say, well, actually this is how much impact we're having and this is what we're doing about reducing what that is.

You should accept that someone should be able to point their finger at your operation and you should be able to stand up. And I think you need to be able to stand up and say, hey, because, you know, there's a lot of perception out there that all farms are bad or all things that are going on in rural is not good. And then we throw a bit back and point the finger at them and say, well, look at what you guys are doing in the city. But that's not getting us anywhere.

We've got to start measuring it and going, well, yeah, okay, we are having an impact and here's what it is, and this is what we're doing to reduce it. And then we can ask the question back to the to the other people and say, well, you know, what's your number and what are you doing about it?

So I think that's really important stuff.

About the farm

Robin and Shirleen Oakley own Oakley’s Premium Fresh Vegetables. They grow potatoes, broccoli, beetroot, and pumpkin across 450ha of owned or leased land in Southbridge on the Canterbury plains.

Aerial image of tractor and potato harvester

Potato harvesting at Oakley's (Photo: Dave Allen Photography)

The Oakley family has been growing crops in the area for over 150 years - the flat topography, Waimakariri silt loam soils and temperate climate make for great growing conditions. Their vegetables are now available year-round (other than pumpkin, which is seasonally available from April-November) at most major supermarkets in the South Island and in parts of the North Island.

Environmental focus

“Growing food comes with responsibilities,” says Robin. “People should be able to ask us how our vegetables are grown, what impact there is on the environment and what we’re doing to reduce it. And we should be able to provide an honest answer.”

Over the years, Robin has developed a detailed understanding of his soil and the crops it supports. Crop rotation is key in Robin’s approach – helping improve soil structure and fertility and minimising build-up of pathogens and pests. A comprehensive precision agriculture programme is also followed.

Man in paddock with soil monitoring equipment

Robin checking soil data (Photo: Dave Allen Photography)

The soil is tested before, during and after crops have gone through and moisture probes help accurately monitor water levels so they can better predict what is needed. The paddocks are e-mapped to determine where there are variances that might affect crop nutrition. Regular plant testing also takes place and fertiliser applications are split throughout the plant life cycle to minimise leaching and increase yield. Cover cropping between rotations helps soak up excess nitrogen and they have significantly changed their cultivation practices, aiming to support good soil structure and health.

Everything is recorded in a database, providing valuable information to help them achieve reliable outcomes from their crops while also protecting their soils.

These efforts have seen the Oakleys recognised with several farm environment and innovation awards.

The Oakleys are also connecting and contributing in other ways. In April 2022 they installed a 220kw solar operation to power their packhouse at Southbridge – one of the largest installations in the South Island. They sponsor charities and sports teams in their community and regularly supply vegetables to their local food bank.  

The Oakleys greenhouse gas numbers

In the next few years, New Zealand farmers and growers will have to know their agricultural greenhouse gas numbers and have a written plan for reducing them.

A number of tools are available for farmers and growers to find out their greenhouse gas numbers. Robin uses OverseerFM to get his - more information on this tool and others is available on our Knowing your numbers page

Oakleys 2020/21
Farm area (ha) 310.2
Total biological GHGs from the farm (tonnes CO2-e) 147.2
Average biological GHGs per hectare (tonnes CO2-e/ha) 0.47
Total methane per ha (tonnes CO2-e) 0.06
Total nitrous oxide per ha (tonnes CO2-e) 1.41
Total carbon dioxide per ha (tonnes CO2-e) 0.04
Total methane (kg)* 775.5
N leaching as kg N/ha 9.8

*The weight of methane is shown here without conversion to CO2-e because this is how it would be required to be reported in any farm-level pricing mechanism.

As shown in the table above, the main agricultural greenhouse gas for Robin is nitrous oxide, driven by the amount of nitrogen fertiliser applied to his crops.

There is also a small amount of carbon dioxide associated with this fertiliser use and a very small amount of methane, emitted by a neighbour’s sheep brought in to graze between some crop rotations.  

Robin has long believed that “you can’t manage what you haven’t measured”. Now that he has his greenhouse gas numbers together, he can turn his attention to identifying ways to minimise his impact on the climate.

On-farm actions

The Oakleys are already farming very efficiently and have been focused on reducing their nitrogen leaching for a while now. The aim for them now is fine-tuning their operations – looking for further ways to reduce nitrogen fertiliser use. Here are the main things they are doing in that area: 

  • Developed expertise in the crops they grow, understanding where and when inputs are needed
  • Sophisticated crop rotation system
  • Variable rate irrigation to optimise crop growth and avoid nutrient runoff
  • Investment in precision agriculture systems to ensure fertiliser is applied exactly where and when it is needed
  • Cover cropping
  • Soil testing to optimise and minimise inputs

You can read about these actions and others on our on-farm actions page

The Oakleys are also adding solar panels to their operation to power the main packhouse and coolstore on site. This is helping reduce their carbon dioxide emissions (separate to their efforts to reduce their agricultural greenhouse gas emissions).

Robin acknowledges that it can feel overwhelming and daunting at the start. His advice to other farmers and growers is to ask for help from the experts, get them to analyse the data and put a report together that is tailored for the farm and will help support decision-making.

“At the end of the day, we’re all caretakers of the land,” says Robin. “We’re all trying to bring out the best in our farms – how we look after them is how they look after us and our families.”

Know your numbers and have a plan

By the end of 2022, all farmers and growers will need to know their annual on-farm greenhouse gas emissions and by the end of 2024, they'll need to have a plan in place to manage them. These requirements are part of the He Waka Eke Noa partnership and are intended to help get farmers ready for agricultural greenhouse gas emissions to be priced from 2025. To find out more on how to do this, see our Know Your Numbers page