For some growers a well mown orchard is a point of pride, while others have been reaping the benefits of minimal mowing and a lush sward for years. Opportunities to improve orchard resilience, meet market expectations, save time, money and the environment, may offer mowing fans new reasons for a rethink.

“Question the need for every input,” is a mantra for Daniel Kenna and his family when it comes to managing their conventional Gold3 orchard, near Katikati in Bay of Plenty.

Two of the inputs they’re currently learning to live without are time and fuel for mowing and mulching. They say it’s a win-win for their bottom line, soil health, and the environment.

“We’re part of the Zespri Carbon Neutral Trial so we’re looking for ways to reduce fuel use and associated greenhouse gas emissions. We already had a minimal approach where we only mulch the older, heavy male prunings that need it, and mow only when it’s necessary for worker comfort and safety. But we dropped one of the ‘necessary’ mows from the trial block last season too and it really wasn’t a problem,” said Daniel.

Daniel manages their 4.4 hectare Hangawera Orchard together with his parents Stephen Kenna, Phillippa Wright and brothers William and James Kenna, and they share a passion for finding ways to improve the environmental, financial and social sustainability of their orchard businesses. As well as being a carbon neutral trialist, Daniel is also one of three Zespri Impact Orchard Network (ION) growers. Through these programmes, he’s leading work with his family to test ideas for improving orchard practices, mainly on a 1.35 hectare trial block, and sharing what they learn with other growers.

“When we took over the orchard it had very little sward and a large brown weed strip which we wanted to fill in. We sowed clover and rye across the whole orchard in our first year, when we grafted it to Gold3 in 2020, but we don’t want to keep sowing seeds every year. The extra sunlight through a developing canopy helped those seeds and naturally occurring plants to establish. Now we’re allowing it to grow, set seed and become a self-sustaining sward,” said Daniel.

They chose clover and rye because they expected those species to establish quickly, do well in low light, and provide nitrogen fixing benefits.

Challenged through the Carbon Neutral Trial to bring their already low emissions footprint (1,925 kg CO₂e per hectare) down even further, Daniel decided that for their ‘necessary’ two mow and one mulch runs, they could further reduce inputs and emissions by one third.

“It was an easy choice to mow with just two passes, to cover the middle of the row and leave the outside edges. We used to do the whole row width with three passes, but no-one’s working in the outside edges so it’s not necessary.

For mulching, we kick the prunings into the middle of the row so we can cover them in two passes instead of three. We’ve also tried different tractor speeds and get a better mulch at about 3.4 km/hour rather than 5 km/hour. The tractor has a digital speedo which means we can easily set it to run at the most efficient rate,” he said.

They use tow behind mulch and mow attachments on an Antonia Caerrero 10/900 100 horsepower tractor. At two passes versus three, they save about half an hour in labour time, and about five litres of fuel per hectare, per mow.

For the trial block, the need for a spring mow decided itself on the day that orchard workers arrived for zero leaf pruning.

“We were at the end of the row discussing whether it needed mowing or not and the workers started walking up the row. The knee-high grass was trampled down in seconds and it didn’t bother them at all. So we saved ourselves a complete mow, and there were no worker complaints or safety issues” said Daniel who notes that there’s really no downside to minimal mowing and there’s a raft of benefits.

“An orchard doesn’t need to look like a golf course. In fact, the soil and vines are probably healthier if it doesn’t. We’ve counted more than 20 different plant species and 12 different fungi in our self-seeding sward – they’re the plants that survive here naturally, and that diversity will be supporting a broader range of pollinators and beneficial bugs. The roots are helping to build soil carbon that improves soil water retention and nutrient cycling.

We’re seeing more sedge grasses, wild strawberries which are said to have a good soil fungi relationship, and less of the weedy nightshade species that we’d otherwise be pulling out.”

Daniel says they tried rolling in the spring of 2022 but the sward bounced back quickly. They’ve considered crimping but with no complaints from their orchard workers, they think the fuel use may be unnecessary.

“We haven’t seen any increase in pest or disease problems, despite our minimal approach to pesticides. And we don’t use herbicide – just wood chip in areas where sward suppression is needed around irrigation sprinklers. We’ve got high vigour and awesome soil, so our fertiliser inputs are also low. That all adds up to very little machinery movement and minimal compaction risk, leaving our soil healthy with great water holding capacity, so we didn’t need to irrigate last year either,” said Daniel.

The results

Daniel has reduced his already low annual on-orchard emissions footprint down by more than five percent; from 1,776 kg CO₂e per hectare to 1,675 kg CO₂e per hectare in the trial block. This compares to an industry average of 4,310 kg CO₂e per hectare.

He’s achieved that with 2024 production of 12,126 trays per hectare across the whole orchard. This compares to a 2024 Gold3 average for the Katikati supply region of 11,290 trays per hectare from orchards in their third year of production.

“We’re really happy with that result from a developing orchard that we’ve made a lot of changes to in recent years. A key focus for the coming season is to keep increasing production while keeping emissions low; so we grow more kilograms of fruit per kilogram of emissions that we can’t eliminate,” said Daniel.

The need to reduce climate change impacts, along with increasing regulatory and market access requirements, are key drivers for measuring and minimising orchard greenhouse gas emissions.

Visit the Manage emissions page on the Zespri Canopy website for an online calculator to estimate your orchard carbon footprint and guidelines for developing an orchard emissions reduction plan. These tools can help growers to meet the new recommended GAP principles that were introduced last year in section 4.7 of the Zespri Grower Manual.