Viticulture

Applying the following viticulture management practices can optimise your soil organic matter leading to greater carbon storage:

• grow cover crops or swards to provide surface cover
• generate growth of organic material and increase root mass at depth
• include a variety of plants (grasses, herbs, legumes, and broad-leaf plants to encourage a diversity of root growth forms and microbial activity)
• select species that invest more biomass into roots combined with well-combined fertiliser regimes that encourage root-microbe associations and increase microbial conversion to humus
• ensure mid rows and vine rows have adequate nutrition and soils are within a desirable pH range for plant growth
• manage any grazing pressure so that plant growth is stimulated
• import composted products to supply humus and increase number and types of soil organisms
• minimise tillage - to maintain surface cover levels
• minimise heavy grazing - to maintain surface cover levels
• compost management to reduce methane emissions
• improved soil health to improve to improve irrigation efficiency with good scheduling to minimise emissions from electricity.

Reducing emissions in viticulture

Grape growing has relatively low greenhouse gas emissions. Most of the emissions come from downstream scope three emissions from transport and manufacturing. On-farm emissions are largely CO₂ from energy requirements. There are also a small amount of emissions from nitrous oxide, and very minimal methane emissions.

Emissions reduction opportunities include:

• sourcing or generating renewable energy on-site
• minimising tractor passes along rows
• strategic nitrogen fertiliser application (rate, source, timing)
• use of specific fertiliser formulations:
  • urease inhibitors
  • controlled release fertilisers (polymer coating can contain micro plastics and have been banned in the EU, however biochar or natural wax could be an alternative)
  • nitrification inhibitors
  • New Zealand has developed Eco-N spray, it shows promising results but is not currently available.

Most of these options do cost more, but may become more necessary to meet emissions reductions targets.

In the not too distant future urea may be able to be sourced from suppliers who produce urea without fossil fuels by using renewable energy. This will reduce Scope 3 emissions.