Compost and Mulch

We have made a commitment to recycle all compostable waste materials from our Yarra Valley site. This includes all grape skins, stems and seeds, paper and cardboard, kitchen, household  and garden wastes. Compost results from the bacterial and fungal breakdown of nutrients in the high nitrogen, green and woody material that we add to our compost 'heaps'. It converts nitrogen, phosphorous and potassium in the compost material into the living form ie fungi, bacteria, protozoa and nematodes.

Different types of farming require different compositions for best results. For our vineyards  we require a fungal compost to improve the diversity and amount of beneficial fungi in the soil within the vineyard.

Typical fungal compost composition used on site is:

• 40% woody components such as sawdust, wood chips, straw, cardboard, paper and grape bunch stems

• 30% green material such as hay, green prunings, grass clippings and grape skins

• 30% high nitrogen material from grape seeds and pea crops grown on-sit

The windrows [rows of compost heaps] are prepared in layers of the different composition materials and are seeded with purchased certified organic compost. Rainwater is used on the windrows to maintain moisture levels at approximately 50%. No animal manures are used at this stage, as they can be a source of E.coli which can impact on the health and safety of the people handling the compost.

The fun starts as the windrows heat up due to the fungal and bacterial consumption of the nutrients as they rapidly reproduce and grow.  When the centre of the windrows reaches  65°C they are turned to introduce  air back into the compost heap and to cool it down.  We must ensure that every part of the piles reaches  65°C for 24 hours to be confident that all the weed seeds and disease pathogens have been killed.

The windrows are turned with a compost turner which moves the heated material from the centre of the pile to the outside and the cooler material towards the centre. As the material is thrown into the air it is sprayed with more water to replace what has been lost to evaporation.

We continue ‘turning’ the windrows until the food source is depleted, indicated by a reduction in heat produced and biologically test it to confirm the compost has the right biology to be spread onto our vineyard soils.

We broadcast the compost on all vineyards and we are trialling the incorporation with the soil under the vine with some tillage. One tonne of aerobically made compost has enough biology and nutrients stored within its cells to replace fertiliser requirements on one acre of our soil.

Last spring we made over 1200 cubic metres of compost, more than enough to apply to the entire 250 hectares of our Yarra Valley vineyards.