Under the Vines

10 September 2015

A successful trial program involving spreading a protective layer of compost under vines is running under a partnership between some Victorian vineyards, the Port Phillip and Westernport Catchment Management Authority (PPWCMA) and Landcare. Representatives from the trial spoke at the recent Australian Organics Recycling Association (AORA) Compost Revolution Conference in Melbourne, presenting an overview of their early findings. Karen Thomas, Regional Landcare Facilitator with the PPWCMA, Peter Ronalds from Western Port Catchment Landcare Network and Joe Vaughan from 100Hunts Vineyard, spoke about how working in partnership was achieving production and environmental benefits. The trials are funded by the regional delivery stream of the Australian Government’s National Landcare Programme. Although early days for the project, Karen Thomas said that interim results were promising. The group told the conference that compost provided an excellent thermal protection on hot days with soil moisture remaining consistent. It also provided good protection after a rainfall event, as the composted rows dried out, while the control row remained waterlogged several days after rainfall. Yield, quality and soil bulk density are being monitored as part of the trials, however, this data will not demonstrate measurable improvements until at least the second year. Anecdotally, Joe Vaughan said improvements he has noticed from the first year of trials include the need for less herbicide and less irrigation. “We wanted to show the local growers the data we collected and what some of the early findings were,” Karen said. They had an excellent response to an information day on the Mornington Peninsula, with more than 50 growers from regions such as Yarra Valley, Moorabool and the Goulburn Valley coming to hear about the trials and see examples of the results.” Declan McDonald says “treatments can-not be one-offs” “there is a lot of research showing the positive effects of compost on soils” farmers are increasingly becoming interested in alternative options to improve their soils and are seeking information on the ‘how to”. Events such as this, with over 50 attendees confirm this trend. “The aim of the trial was to look at protecting the environment, while still efficiently and economically producing the premium grapes that we need for wine,” Mr Vaughan said. “We’re looking at reducing the weed density under the vine, so, reducing the herbicide use. And it’s also a buffering effect to protect the vines from the elements on extreme heat days.” “What we’ve been testing for is the soil chemistry, we’re doing PL testing on the vines themselves, and grapes analysis at harvest for sugar and taste”, Mr Vaughan said. “We’ve put moisture sensors in the ground, which are logging soil moisture every 10 minutes and also the soil temperature every 10 minutes. On our vineyard, we have reduced the herbicide use from four applications a year to two”. For more information on the Australian Government’s National Landcare Programme, please visit ppwnew.ppwcma.vic.gov.au. Snapshot of results: Our trial data 6 months on from compost application confirms previous research that shows: • An improvement in soil moisture • An improvement in the evenness of soil temperature (it doesn’t fluctuate as much between night and day) • Improved protection on very hot days. Joe Vaughan notes that, “we’re finding anecdotally that there’s a buffering effect from the compost from hot and cold and wet and dry. • Improvement in soil structure “this is evident by the recent rainfall event in April. The control row took longer to dry out after reaching waterlogged than the fine compost and coarse compost rows, which dried out quite quickly following the rainfall” event says Declan McDonald. • Possible improvement in soil biology biomass. Joe thinks that he’s “finding an increase in the biology of the soil in terms of the microbes and fungal populations – which is good”.