Indevin has found a sustainable solution to the problem of dealing with the solid remains of the grape, known as grape marc.
Working with Big Bale Contracting and the Marlborough District Council, Indevin is ‘green spreading’ the marc onto bare land at Bankhouse Estate to inject nitrogen into the soil.
Why is grape marc a problem?
Grape marc is the skin, pulp, seed and stem of the fruit that remain after pressing for juice. If marc is stockpiled for a long time it can start to leach, causing problems for water and soil quality.
Green spreading is a known solution and has been successful in other regions.
At Indevin the marc is captured in a purpose-built concrete bin and trucked to Bankhouse. The Big Bale team spreads the marc within 16 hours of it arriving, as it must be spread within 48 hours to prevent leaching.
In preparation for new season cropping rotation, the marc is worked into the soils of predominantly barley or corn crops harvested immediately before the grapes were.
Indevin has worked with the council to ensure they are happy with the spread rates (tonnage per hectare) as guided by a soil consultant.
Marlborough soils typically have low organic matter, so the marc assists in building that up to help soil structure, health and water retention.
Specialised equipment including a Canadian Degelman muck spreader with variable speed and self-weighing technology, used in conjunction with GPS positioning, ensure the marc is spread accurately and within the consent limits.
The spreader is set to spread 40 tonne per hectare and the goal is a double spread to 80 tonne. The consent allows 90 tonne per hectare per season, and the soil is monitored annually.