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By comparing the financial outcomes of the regenerative paddock and the conventional paddock, the project aims to inform farmers of potential benefits and provide practical advice. 

CVRF project officer, Ross Davey, said the financial outcomes will be assessed by quantifying input costs versus monetised production results, in the form of net feed utilised by stock converted to a theoretical stock weight gain. Natural capital improvement will also be part of the financial outcome assessment. 

Two paddocks, two approaches

The regenerative methods adopted include:
•    Multi-season use of annual multi-species cover cropping
•    Minimal use of pesticides and chemical fertilisers
•    Application of biological amendments
•    Establishment of multiple species perennial pasture
•    Adaptive multi-paddock grazing. 

Conventional methods include:
•    Minimal species ‘clean-up’ cereal and clover crops
•    Strategic use of chemical fertilisers
•    Establishment of simple two mix perennial pasture
•    Set stocking. 

Implemented on a 40-hectare block of a large corporate farm, the practices were designed to be practical and simple to fit labour resources and farm routines. 

Assessing the outcomes

To quantify production outcomes, Feed On Offer (FOO) assessments were used instead of actual stock weights. This was due to the difficulties of weighing stock and maintaining consistent stock attributes for comparison. 

Dry matter tests at strategic times produces net feed utilised by stock, which is converted to a standard theoretical stock weight gain and thus financial return. Input costs are available from farm operation records. 

Challenges

After a number of seasons of sowing simple annual ‘clean-up’ pasture mixes the conventional paddock was sown mid-May with phalaris, clover and oats. The regenerative paddock was sown in early June with chicory, plantain, sub-clover, strawberry clover, rape, radish, linseed and phalaris after a number of seasons of multi species cover crop sown as annuals. The aim was to establish perennials on both sides. 

Mr Davey said cold weather impacted the growth of perennials, and this was expected to shorten the period of grazing of any resulting perennial pasture. A lack of rain after sowing also had an impact. 

The extreme rain period from early November to the end of December 2022 meant that growth of pasture on both sides was severely retarded for three months. Entry to both paddocks was totally curtailed due to the wet; no stock could be put onto the paddocks and no application of biologicals was possible. 

Measurement of Feed on Offer was finally possible in mid-January 2023, but by that stage many of the pasture species had matured past being quality feed.

Project agronomist Jade Killoran observed that the chicory on the regenerative side was prolific and had started to seed, the phalaris had seeded and the clover was growing well – all good foundations for a stronger establishment of perennial pasture for future seasons. 

Evidence to date

Averaged over all seasons, the financial returns on implementing regenerative practices to improve pasture and soil is a ‘no regrets’ strategy compared with conventional methods.

“There is no financial disadvantage; you certainly wont lose money” Mr Davey said.

“On top of that we can already see substantial anecdotal evidence of superior soil health improvement in the paddock using regenerative practices. If natural capital improvement is accounted for, it is anticipated that improved financial outcomes will result.”

Possible outcomes

As a result of this project, a template could be developed for a soil and pasture improvement program using multi species cover-cropping, perennial pasture establishment, and biological amendments (minimising high cost chemical fertiliser inputs).

Mr Davey said farmers needed further assurance that moving from conventional pasture management to a regenerative approach could be a financial “no regrets” strategy.

“We could have evidence that in a three-year period it is possible to have identifiable improvements in soil natural capital and pasture resilience showing a trend that should continue over a longer time,” he said.

Advice for farmers

Mr Davey said farmers still needed to make informed decisions.

“Selecting a trial area that is a significant, but small, part of one’s operation in order to assess optimal regenerative approaches and test best practices for your area is a wise move,” he said.

“There are many variables in inputs, timing, species selection, stock management etc that is best trialled first to ensure your investment is optimal. 

“Always conduct trials first with comparative areas and controls, but avoid the temptation of overcomplicating the variables. 

“Stick to the plan but be reactive and adaptive and document the plan, variations, decisions and outcomes.”

Laurel Park has both conventional orchards and high-density planting, which is being trialled alongside the cover cropping. “Where we used to have one tree, we now have three…” Tom said. 

The floods which destroyed Lismore in February and again in March 2022 (over 3m of rainfall) resulted in a loss of 560 of Laurel Park’s avocado trees. 

The main issue on the farm prior to this was Phytophthora. “There’s good evidence that more organic matter will fight that. So, anything that involves more organic matter is good,” Tom said. 

Sourcing the seed was also tricky due to the floods. “I think all of the rural stores were just a bit messed up... I think they actually had stuff that floated away.” 

Dr Karina Griffin took soil samples at the beginning, middle and end of each trial. 

While it is too early to have any solid data on the effect of the multispecies cover crops, Tom has made a few observations: 

• There’s a lot less soil compaction in the cover-cropped areas, which is a good thing.
• He noticed a lot of bee and assassin bug activity when the cover crops are in place (assassin bugs are beneficial insects that prey on pest insects).
• In terms of the soil sampling data, no solid conclusions can be made just yet.  

“There have been some differences in the cover cropped areas versus the control, but not large differences over a significant time period, so you can’t make any management decisions based on the soil health test,” Tom said, “But you can watch it over time and see what’s happening.” 

Tom has enjoyed the University’s trial process, saying it “makes a lot of sense” given the research that has been done into avocados and organic matter. 

“My joke is when you think you’ve put enough organic matter on, put some more on. You just can’t have enough; you see the soil and the trees respond to it,” he said. 

Read the full case study here: Case Study: Laurel Park Avocados and Macadamias.

Presented by Professor Terry Rose, Dr Karina Griffin and entomologist Dr Christopher Carr, the team discussed soil health and the cover crop trails they have been undertaking in the inter-rows of Northern Rivers coffee, macadamia and avocado plantations. They also detailed Dr Carr’s current findings as to the effect of cover cropping on beneficial insect populations.

While it is too early to come to any firm conclusions as to the efficacy of various cover cropping techniques, the use of lablab in coffee plantations was ruled out. By June 2022 at Zentveld’s, lablab was highly dominant and had shaded out all other ground cover, it also caused significant issues in the plantation as it climbed all over the coffee plants.

Another preliminary conclusion is that little positive impact on soils can currently be attributed to the summer cover crops sown, as the endemic perennial, summer-growing ground covers in the control plots produced an equal amount of biomass to the sown cover crops. Smothering from summer cover crops has the potential to weaken the existing summer-growing perennial groundcovers, which is not desirable.

Winter cover crops, however, appear to have made a noticeable difference in labile carbon in the winter-spring period. Presumably this is because more biomass was produced where winter cover crops were over-sown, compared to the control plots, where existing groundcovers were relatively dormant. Control areas were not mown for the duration of the cover crop cycle.

“Short story is, these winter cover crops do seem to be improving our soil health by producing additional biomass over the winter period. Further, these cover crops can be direct drilled into existing perennial groundcovers in autumn, so groundcover is maintained. Bare soil at any time of the year is undesirable in the northern rivers, where intense rainfall events can occur at any time of year and cause erosion on sloping lands. It appears that we can establish winter cover crops in coffee plantations without ruining our perennial base, so these winter cover crops look like they’re a bit of a winner in terms of soil health,” said Professor Rose. Winter cover crops are more challenging in many macadamia plantations, where nuts need to be harvested off the ground over the winter period.

This message was repeated throughout the day, the key takeaway being that regardless of what is growing in the inter-rows, whether it be weeds, native grasses or cover crops; they all have a beneficial effect, increasing biological diversity, biomass and holding the soil together in heavy rainfall. In summary, growing anything on the ground between your trees is preferable to bare dirt.