Curtis - Achieving zero carbon agriculture requires access to water

Irrigation NZ CEO Andrew Curtis says a clear strategy regarding water use and conservation is essential in the move toward a lower carbon agriculture sector.

The government’s Zero Carbon discussion paper constitutes a major rethink about the future of farming in New Zealand. Seeking to achieve a lower carbon economy, the discussion document suggests that the amount of land used for horticulture and crop production could double or triple over the next thirty years, while sheep and cow numbers reduce slightly and forestry expands.  

Future national planning around access to labour, technology and support to reach international markets is needed for this shift to be successful, as well as policy around how land use changes might be supported.

Access to water is another key issue which underpins the zero carbon discussion but hasn’t yet been debated. The majority of fruit, vegetable and wine production in New Zealand today is on irrigated land. Irrigation will become even more important with more frequent droughts forecast as a result of Climate Change. In the future, even rainfall rich regions will be subject to regular droughts.

The drought conditions affecting a slew of regions (Southland, Northland, Wellington, Canterbury, Otago, Hawke’s Bay and West Coast) last summer was a foretaste of things to come. Drought like conditions were followed by heavy rainfall and flooding in many regions. Food prices went up, farmer incomes went down, with a flow on impact on the government’s tax take.

The importance of water for food production is highlighted by the fact that according to the United Nations, irrigation helps produce 40% of the world’s food supply on just 20% of the world’s agricultural land. If we want to become more productive and more efficient with our land use in order to generate more jobs, we need to recognise the value of irrigation. Currently we eat nearly all of the vegetables grown in New Zealand and in 50 years time we will need to feed an extra 2 million people, so we also need to be planning for this situation now.

Water is commonly seen as being in short supply in New Zealand, but we actually receive around 550,000 million m3 of rain each year according to NIWA. About 80% of this flows-out to sea, supporting river ecosystems. 18% of rainfall evaporates after it lands and 2% of our national rainfall total is used by humans. While there is regional variation and some areas where water is fully allocated, the United Nations rates New Zealand as having ample renewable water resources. 

We are already capturing and using some of this valuable water, and Northland is an example of what the future of Zero Carbon farming in New Zealand could look like.  The Kerikeri Irrigation Scheme has been operating for over 30 years and mainly helps produce kiwifruit and citrus fruit.  An Impact Assessment of the schemes value showed that the scheme had created 1,300 additional jobs and added $106 million per year to the Northland economy.

The assessment found no adverse environment effects from the scheme on local waterways. People living near the scheme had higher home ownership rates, higher household incomes and higher full-time employment rates than the rest of Northland. Having seen the changes in Kerikeri, the Northland Regional Council is now looking at a range of options to develop irrigation to grow crops like avocado, oranges, potatoes, kumara and lettuce. Up to 2,700 jobs could be created. The Council is looking for water storage options which provide multiple benefits – like suppling water for townships, providing water to supplement river flows and offering flood protection.

According to the Ministry for the Environment climate change will result in heightened demand for water in dry, hot summers with reduced soil moisture and groundwater supplies, increased risk of drought and changes to river flows. Collecting rain and river water in dams for shared domestic and agricultural use will help reduce the devastating impact of the climatic changes. Developing water storage also allows for water to be released into rivers when low flows occur over summer which is beneficial for water quality. There is also the potential to improve the water storage capacity of our existing infrastructure and modernise older infrastructure to become more water efficient.

To be successful internationally, each country should specialise in producing what it has a competitive advantage in creating. We don’t have minerals like Australia or an abundance of workers like China or India, but we do have a  combination of a temperate climate, good soils and ample water resources which makes us ideally suited to agricultural production.  Alongside this, the ecological role of waterways needs to be recognised and protected.

As only a small percentage of land is suitable for horticultural production, pastoral farming will continue to play an important role in our future economy too. With more frequent droughts occurring, irrigation helps provide enough pasture to meet animal health requirements. 

Irrigation is estimated to add over $5 billion to New Zealand’s GDP. Whether we have access to irrigation will affect our future food prices, and the income of rural economies which has a flow on impact on how much money is available to fund schools, hospitals and superannuation.

If we want to make the shift to different farming models we need a pathway forward to adapt agriculture to operate in an low emission but increasingly volatile climate. We need to invest in water storage to allow increased horticulture and crop production to occur. And we need to value the role irrigation plays in future proofing our food supply and protecting our national economy from the buffers of climate change.

The starting point for any of these changes is a clear strategy towards water, along with a much needed bipartisan approach to this issue which enables policies to be set based on the best long term outcomes for New Zealand.

If we don’t have agreement on water policy trying to develop future water infrastructure becomes extremely difficult. And if farms don’t have water, we can’t make significant expansions to horticulture and crop production, meaning #ZeroCarbon farming is not part of our future.