Tinamba Turf general manager Hugo Struss. Photo: Supplied

Convinced by on-farm trials showing significant fertiliser and water savings from applying organic compost, the team at Tinamba Turf has expanded its R&D program.

General manager Hugo Struss said they started with a nitrogen efficiency study on the Gleneagle farm, in conjunction with ICL, at a time when sky-high fertiliser prices “were scaring the bejesus out of us”.

Phosphate and nitrogen fertiliser prices had already been on the way up in 2021, but skyrocketed after Russia invaded Ukraine in February last year. They peaked at more than $1800 per tonne, before falling almost 40 per cent earlier this year, but remain at almost double the rolling five-year average before 2022.

As part of the nitrogen study, soil tests were carried out before, during and after, and they monitored turf health, colour, vigour and strength in Wintergreen Classic Couch that received a range of fertilisers at different rates and timings during the growing season.

Hugo said they had been inspired by the work of Dr Mick Battam, principal soil and irrigation scientist at AgEnviro Solutions, who gave a presentation on turf nutrition to the 2017 Turf Australia national conference.

“Mick has done a lot of work with Turf Australia in the past and we wanted to incorporate his logic and what he found into our trials,” he said.

“We wanted to try to disprove his theories on nitrogen usage as well as seeing his results for ourselves. And we also wanted to try to better the options that are out there so we incorporated his organic trial into it as well.”

Dr Battam, whose slides are available on the Turf Australia website, had conducted soil tests on 18 turf farms and found composted garden waste offered closest to the optimal NPK ratio of 9:1:7.

Hugo said the trial without compost became “quite predictable” with more nitrogen resulting in more growth. By contrast, plots that received compost and less nitrogen equalled or surpassed the quality of those treated with higher nitrogen rates but no organics.

The compost they used was sourced from a local supplier, NuGrow, after they unsuccessfully went looking for a product offering the same components as that used by Dr Battam.

Hugo said their priority had been to find an organic compost made largely from green waste, and containing a wetting agent to help hold onto moisture.

They tested spreading compost on regrowth and bare earth that was later replanted using the conventional method of plug planting.

The compost was incorporated with a rotary hoe at 100 tonnes per hectare and in further trials, chicken manure was added to the paddocks as well. Trials are currently underway to determine the best timing for this application and if it can be done without the added cost of replanting turf.

“That was simply based on the math of it,” Hugo said.

“Anything less was like throwing a needle in a haystack and expecting to be able to see the needle. Whereas, where we went to 100t/ha it gives you an actual 10 per cent ratio of change. If we weren’t amending up to 10 per cent it wasn’t really worth the exercise.”

The results have been significant: Hugo estimated fertiliser savings of 10-15 per cent and a 20-25 per cent reduction in water use.

“They’re estimates, but we do have that data and maybe at some point we’ll share it,” he said.

Since then, they’ve decided to expand the trials from 1000 square metres to several thousand square metres and placed them in different soil types, ranging from sandy loam to dark alluvial soil on the floodplain at Gleneagle and Chambers Flat.

The plan is to carry out more detailed testing of nutrient and moisture retention.

Hugo’s parents Stephen and Jane started Tinamba Turf in 1988 on the former dairy farm near Beaudesert that has been in the family for more than 100 years.

From the original 250ha they expanded to become Australia’s biggest turf producer, with 324ha at Gleneagle, north west of Beaudesert, and the 85ha Clifton Park Turf Farm at Chambers Flat which is also on the Logan River.

Stephen also established a broiler farm on the Gleneagle property in 2004 as a means of diversifying the business, and producing their own chicken litter to the standard they need at 30 per cent less than it cost to buy litter from other farms in the area.

The farms have been GPS mapped, laser levelled and graded to maximise water harvesting from the typically heavy summer rainfall into dams which have a total capacity of 750 megalitres.

“We catch over 65 per cent of the water on our farm at Tinamba,” Hugo said.

“In south east Queensland we’re about storms, we’re not about nice long rain events where it all runs down the river and we get to pump it out. We get thumped in an hour and a half. And then three days later we get thumped again, for an hour and a half, and our water system is all set up to deal with that.”

Other challenges include managing ever-increasing input costs.

Hugo said it was “scary” that so many farmers did not know how much it cost them to grow turf.

“It’s great that we’ve been able to as an industry plod along like that and have around about figures,” he said.

“But I think as sales become increasingly tight, for farmers to make it and for farms to be successful, they need to know their costs and manage their costs, which is the process that we’re going through at the moment.”

Tinamba Turf has nearly 400ha of turf under irrigation, mostly using centre pivots, across its farms and produces green couch varieties such as Grand Prix, Wintergreen and Wintergreen Classic, and Monarch Zoysia, Fortress Buffalo and Sir Walter Buffalo.

Most customers are commercial clients needing large volumes of turf for sports fields, new subdivisions and stadiums.

In 2018 they won the contract to supply and lay Grand Prix Couch at Eagle Farm racecourse and in 2020 they supplied and planted 1.2 million square metres of Grand Prix Couch for what was dubbed Brisbane’s biggest lawn – the surroundings for Brisbane Airport’s new $1.3 billion runway.

This article appeared in the Summer 2023-24 edition of Turf Australia magazine