Regenerative Agriculture can redefine best practice viticulture, but there is no ‘one size fits all’ blueprint for vineyards.
That’s the conclusion of 2019 Nuffield Australia Farming Scholar, Richard Leask, who has just completed his final report, ‘Is being sustainable enough for Australian wine?’.
Regenerative Agriculture is a system based on mimicking nature by having a diverse range of plant life storing and cycling carbon and increasing soil microbial diversity and activity through interaction with these plants.
Richard said the benefits for grape growers adopting the principles were multi-faceted – and well worth the effort.
‘I believe that Regenerative Agriculture could provide the Australian wine sector with a system that increases soil capacity and microbial diversity. This could improve water capture and retention and challenge the reliance on synthetic chemicals and fertilisers – and the increasing role of cultivation in organic vineyard systems’, Richard said.
‘In turn, this could be the key to unlocking the individual 'terroir' of vineyards and provide a unique environmentally friendly story to consumers.’
‘Optimising soil health and capacity through regenerative thinking is the key to building resilience and productivity in our vineyard systems’, said Richard.
Nuffield Scholar Richard Leask
According to Richard’s report, the top six practices of Regenerative Agriculture include:
Balance your soil nutrition – without synthetic fertilisers
Richard says internationally, there are two distinct ‘thought camps’ on balancing soil nutrition: Input Balancers (where many leading experts believe that some form of nutrient balancing using inputs is required to keep the plant functioning at its peak photosynthetic capacity) and Plant Balancers (using a diverse group of plants from as many plant families as possible to balance out any nutritional issues).
Richard believes there is no right or wrong answer, as there are many examples of both management practices being used successfully.
Keep your soil covered
Without either a green growing cover or a decomposing litter layer, the 'glue' that helps provide the soil structure through the plant-microbe interaction is broken – and the soil is susceptible to erosion and water loss through evaporation. Soil cover also buffers the soil microbe community against temperature extremes.
‘Even a 10cm layer of rolled cover crop mulch can significantly reduce soil surface temperature’, said Richard.
Minimise soil disturbance
Excessive cultivation destroys soil aggregates, significantly decreases water infiltration rates, accelerates the breakdown of soil organic matter and disrupts and diminishes the complex (and important) mycorrhizal fungal network.
Richard said mid-row cultivation disturbance could be reduced or eliminated using appropriate seeding, mowing and rolling equipment.
Increase plant and microbial diversity – above and below ground
To help build resilience in soil a diverse range of plant species is needed above the ground to cultivate a diverse microbial ecosystem below the ground. This can be achieved by cover crop ‘cocktails’.
‘The mid row area of the vineyard provides a great opportunity to experiment with different plant species to kick-start microbial diversity’, said Richard.
Incorporate living roots into your farming system all year round
Every green plant is a solar-powered carbon pump, says Richard. He recommends having living roots in the system ‘for as much of the year as possible, to keep feeding the microbial ecosystem’.
Integrate and manage livestock
Richard said during his scholarship year he observed the benefits of intensive rotational grazing across a number of different farming systems, with ‘obvious benefits to soil health’. The key is to keep stock moving regularly to ensure soil is not compacted, or the pasture overgrazed.
‘These six practices give a blueprint to create a healthy, diverse, living soil microbial ecosystem’, Richard said. ‘And over time, this produces a high functioning soil capable of high productivity and increased quality.’
You can read Richard’s final report here.