Mission Estate Winery

April 2016

An environment award for a focus on soil health and an Organic Focus Vineyards project

New Zealand’s first winery, Mission Estate was established by Marist missionaries from France in 1851.  Both sacramental and table wines were produced at the estate which remained a seminary for priests and students until 1991. The first record of a commercial sale of mostly dry red wines dates back to 1870 and foundations of the present hillside vineyard were put down in 1897.

Today, viticulturist Steve Wheeler manages 33 hectares of vines for Mission Estate. The company also contracts crop and owns a 70 hectare vineyard in Marlborough. 

Mission Estate Winery won the soil management category of the 2015 East Coast Ballance Farm Environment Awards.   The award focuses on excellent management of soil structure, appropriate fertiliser use, sound knowledge of nutrient budgeting and impact on ground and surface water.

Winning the soil management category was a pat on the back for Steve and his employer, Mission Estate Winery based at Taradale near Napier.  Steve manages 33ha of vines at Mission Estate, and also oversees grape production at the company’s 70ha vineyard in Marlborough’s Awatere Valley and coordinates fruit supply from 12 contract vineyards in Hawke’s Bay.

Steve who holds a Master of Applied Science in Viticulture from Charles Sturt University in Australia and a Bachelor of Horticultural Science from Lincoln University, is especially interested in soil health.   “I think about soil as a growth medium and living organism,” he says.  “It’s not just dirt that you chuck water and fertiliser on but has biological, chemical and physical properties like fungi, bacteria, structure, texture, pH, nutrient content and water-holding ability.”

Healthy soils are required to grow healthy vines, he says.  Grapes are not a high nutrient-demanding crop, so haphazardly throwing on too much fertiliser might produce obese vines and possibly cause leaching into the aquifer.

Each of Mission Estate’s three Hawke’s Bay vineyards is on distinctively different soils.  White varieties chardonnay, pinot gris and sauvignon blanc grow on heavy silt loams while low-vigour red varieties merlot, syrah and carbernet grapes are in blocks with lighter, free draining gravel and shallow sandy loam.

Using GPS technology, heavy and light soils have been identified then mapped, based on ability to hold soil moisture and denseness of canopy growth.  Soils differ not only between blocks but also within rows, affecting decisions on canopy management influencing crop loading and grape quality. Techniques including leaf plucking and removal of shoots and bunches are used to balance crop loading with the vines’ potential to maximise flavours.

Differences between soils create differences in fruit attributes such as ripeness, yield and flavour, making it possible to selectively harvest parcels as they ripen to winemaking requirements.

Steve tracks trends in the grapes’ nutrient levels by tissue and soil testing.  Rather than waiting until vines turn yellow because they are stressed, he identifies any deficiencies early so they can be corrected.

About 70% of Mission Estate’s Mere Road vineyard is organic, likely to be increased to 100% next year with winemaker Paul Mooney convinced this management results in higher quality wines.

This was one of three vineyards which came under the microscope during a three-year Organic Focus Vineyards project which ended in 2014.  Researchers compared vine performance and wine quality in side-by-side, conventionally and organically managed blocks in Hawke’s Bay, Marlborough and Central Otago.

Paul says organic management appears to have improved the aroma and texture of syrah and merlot wines, giving purity of aroma and a big mouth feel.

“It’s my hunch that microflora in the soils have a huge influence which is where organics comes in,” he says.

Grower group Organic Winegrowers New Zealand, funded by the Ministry of Primary Industries’ Sustainable Farming Fund, initiated the Organic Focus Vineyards project in response to a recent surge of organic conversions in the wine industry.

At Mission Estate, organic grapes proved to cost less to grow than conventional grapes, with little reduction in yields and no pest and disease problems.

Steve says the main difference between the blocks is that on the organic block, grapes are under-vine cultivated, the traditional method of weed control, rather than sprayed with herbicides.  The mechanical weeder used was very slow and “pretty brutal”, its sharp blades flicking in and out of vines to slice weeds, but did the job.  However, 100mm of rain in four weeks in late November/early December 2015 made it difficult to keep on top of weed growth.

Steve suspects that the days of spraying weeds with the glyphosate used in the conventional vineyard, are numbered.  There was increasing evidence that this widely-used herbicide, branded Roundup, had an antibiotic effect on desirable soil fauna and flora.  Over-use was leading to weeds developing resistance and over-the-counter sales were this year banned in France due to its use being linked with cancers.

An innovative recycling sprayer, designed by FMR Group in Blenheim, straddles canopies and sprays through the vine collecting any excess product as it passes from one side to the other. This saves drift, avoids accumulation in the soil and reduces refilling trips.

“This is good for the environment and good for our bottom-line,” says Steve.