Compost under vine trial continues in the Macedon Ranges

20 March 2020

The Port Phillip & Westernport CMA, in partnership with Macedon Ranges Vignerons Association, AORA, GrapeLinks and Veolia, is undertaking a three-year trial into the financial and environmental benefits of composted mulch from urban green waste under cool climate Pinot Noir vines in high altitude vineyards of the Macedon Ranges.

Funded through the Victorian Government’s Wine Growth Fund, the project aims to assess ways of avoiding herbicide use and improving root conditions for vines.

The mulch was spread under 25 vines in September 2019, just prior to budburst (emergence of spring leaves on vines).

In February 2020, vines in the mulched rows at each of the three sites had grown past the top wire (see image below). In comparison, the vines in the control row (with uncontrolled weeds) were far less vigorous.

Samples of 100 petioles (the stalk that attaches a leaf to the plant stem) were taken for nutrient analysis from the mulched row and the control row at flowering in mid-December 2019. At the time, the results showed no significant difference in nutrient flow to leaves.

At one site, a burst dripper under one vine in the control row resulted in untypical growth and clearly demonstrated the competition for water from undervine weeds early in the season.

Aerial and soil temperature above and under mulch continue to be recorded and laboratory tested grape quality will be assessed in the next month.

Mid-season in the trial. Right row: mulch applied before budburst under 25 vines. Left row: control, no undervine management, weeds inhibiting vine growth except in one vine where a dripper had burst. Soil and aerial temperature loggers are inserted in both rows. Image courtesy of Darryl Ward.

This project is supported by the Victorian Government, Macedon Ranges Vignerons Association and AORA.

The concept is based on trials undertaken on the Mornington Peninsula between 2015 and 2018, which saw positive grape quality results from Pinot noir with recycled composted mulch under vine.

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