The corporate dairy sector is by far our biggest contribution to global climate change. Intensive farming is resulting in rising methane and nitrous oxide emissions.
Over time, New Zealand's dairy sector has shifted from traditional pasture farming to a more intensive, corporate model. This is having a huge impact on the environment, rapidly increasing greenhouse gas emissions, eroding the clean and green brand on which New Zealand agriculture is built, and lowering economic returns to farmers.
Chemical fertiliser - a corporate treadmill
One of the main problems is the use of chemical fertiliser. Legumes (such as clovers) used to provide the pasture's nitrogen but this traditional method has been replaced with chemical fertilisers, which have increased in use by 617% since 1990. The main culprit is called Urea.
This high-input farming model is creating a fertility time-bomb in our soils. It's a vicious cycle - the more fertiliser used, the more natural sources of soil fertility are destroyed, and the more fertiliser you need each year to maintain production levels for pasture growth. The corporate fertiliser companies are the only winners.
In line with the increase of Urea is the increase of nitrous oxide emissions - up 27% since 1990.
Using chemical fertiliser for short bursts of pasture growth lets farmers maintain (and increase) high stock numbers per hectare, which causes soil 'compaction' and prohibits it from 'breathing'. Air spaces in soil are essential as it needs air and water to travel through it constantly or the roots and beneficial micro-organisms won't flourish. Compacted soil leads to water logging, where bacteria that survive without oxygen flourish and create nitrous oxides. A healthy soil will have around 60% of its volume as air spaces.
As well as damaging soil and pasture growth, allowing large herds to graze on degraded, highly fertilized soils produces much greater quantities of greenhouse gas emissions. Herds are also more prone to digestion problems - thought to be linked to increased methane production from the animal - and a host of other health issues.
The intensification of our dairy farming practices is also eroding our clean green image on the international stage. New Zealand's traditionally low emission and energy efficient farming methods have helped counterbalance the 'food miles' concerns of overseas consumers. But we're losing our edge. Reports indicate that even in the early part of this decade, low emission farming in Sweden and the Netherlands has starting to equal or surpass New Zealand in terms of emissions performance; before 'food-miles' are taken into account.
Worse, New Zealand's dairy farming greenhouse gas emissions performance is moving close to that of the UK. This increases the risk of future market erosion, particularly in light of UK supermarkets' recent initiative to implement "carbon lifecycle" labelling on products. As intensification of New Zealand dairy continues, the carbon footprint advantage that our dairy produce has had around the world is being lost, to the detriment of future generations of our dairy farmers.