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IrrigationNZ Banking Partner
Freshwater use in NZ – we have to do it right
By Susan Kilsby, ANZ Agriculture Economist.
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Irrigation is considered an important tool to mitigate the impacts of climate change. The 2020 United Nations World Water Development Report states: “Combining climate change adaptation and mitigation, through water, is a win-win proposal as improving the provision of water supply helps combat both the causes and impacts of climate change”.
“Improving the provision of water supply helps combat both the causes and impacts of climate change.”
Current global farming practices will not sustain the world’s future population. Many parts of Asia are expected to have water shortages in the future and will either have to become more efficient at using water, or will need to import more food.
The FAO estimates China is already irrigating nearly all of the land it potentially can. India is only irrigating about 50 percent of the area of land that could be irrigated but water shortages are expected to limit further expansion.
New Zealand is one of the few countries in the world with plenty of freshwater available. However to capture the benefit of this valuable natural resource more water storage facilities are required.
New Zealand is already well connected with Asia from both a geographical and trade perspective. We are well positioned to benefit from the elevated levels of economic growth this region is experiencing relative to the rest of the world. Even in the subdued economic environment China’s economic is expected to grow this year. The IMF has forecast the economies of emerging and developing Asia will contract by just 0.8 percent in 2020 compared to the global average growth rate of -4.9 percent. Asian consumers are highly conscious of food safety and quality. As average incomes in these regions grow so will their demand for high quality imported food.
Irrigation provides an opportunity for New Zealand to increase productivity levels and allows more diverse uses of land. Irrigation is also a tool that can be used to manage weather and climatic risks and therefore also mitigate financial risks.
Producing more with less is becoming increasingly important as the agricultural sector faces limits and costs associated with greenhouse gas emissions and nutrient emissions.
This trend is encapsulated in the government road-plan for the primary sector “Fit for a Better World – Accelerating our Economic Potential” which recognises the importance of irrigation.
Maintaining production and profitability whilst reducing emissions is a massive challenge for our primary sectors. The government would like to see an extra $44 billion of export earnings generated, in total, over the next decade which is an ambitious target. To even get part way down this road there is no doubt we need to dedicate more land to high returning uses, many of which will require irrigation.
Improving water storage has been identified by the government as a transformational opportunity to improve productivity. While this is not new thinking for most of the primary sector is good to see the current and potential value of irrigation being recognised by the central government.
An increase in small scale water storage is expected to generate an additional $500 million by 2030, with $300 million coming from horticulture, an extra $100 million from dairy and $100 million from meat and wool. This investment is also haled to build community resilience to climate pressures.
A study by NZIER1 based on data from 2011-12 identified that irrigation contributed $1 billion in export earnings. No doubt export earnings that could be attributed to irrigation will have expanded even further in the past decade, but generating an additional $500 million from new irrigation is still a lofty target.
Irrigation reduces the risk of not being able to efficiently finish livestock, enables more flexible farming systems, and reduces the risk of having to off-load stock during dry periods
a t cap i p er ³ m d n sa o u h T
90 80 70
60 50 40 30 20 10 0
a a d Ca n d e ala n Z New i a s s u R
a/ c r i e m A n Lat i e an bb i Ca r a l i a r st u A s e t a S t d t e i n U an r a h a S b S u ca i Af r World average
o n i n U e a n p u ro E a n i C h i a A s h u t o S a i d I n
(Source: Aquastat 2014. Renewable internal freshwater resources flows refer to internal renewable resources (internal river flows and groundwater from rainfall) in the country. Renewable internal freshwater resources per capita are calculated using the World Bank’s population estimates.) 1. NZIER and AgFirst Consultants NZ Ltd. (2014). Value of irrigation in New Zealand: An economywide assessment. Retrieved from: https:// www.mpi.govt.nz/dmsdocument/5014/send
when market prices are typically low, or cut short the milk production season.
Intensification of systems, whether due to irrigation or not, can result in a higher nutrient loading, coming either directly from the extra livestock being carried or from increased use of fertilisers. However, irrigation done well reduces nitrogen run-off, by ensuring that the water is delivered to dissolve the fertiliser at precisely the time that the plant requires it and is able to absorb it. If rain is forecast on dryland pasture, fertiliser is spread, but then the rain doesn’t arrive, that fertiliser will dissolve at some later date which may not be the optimal time for the plant to adsorb it. Too much rain and/or a lack of uptake by the plant and the nutrients will leach through the soil into waterways.
Our farming and orchard management systems are becoming increasingly complex and sophisticated, including our irrigation systems. Water and nutrients are increasingly being applied in a more precise manner based on soil data readings and/or sophisticated modelling. The need to place water more efficiently onto the land, and in a more automated way, is reflected in the move away from flood irrigation to pivot irrigators.
Irrigation has a role to play in enabling alternative land uses. The ability to apply water when required means land can sustain a wider range of enterprises, particularly more intense arable and horticultural uses. Without access to water it would be too risky to invest in a number of these higher-value crops. Some crops don’t require a large quantity of water, relative to pastures, but they do require water at strategic times.
New Zealand has an opportunity to continue to grow our role as a reliable supplier of high quality, ethically produced food. Used appropriately, irrigation can enable a wider range of crops to be grown, improve animal welfare, and reduce greenhouse gas and nutrient emissions, but used inappropriately it can enable negative environmental outcomes. We have to do this right.
IRRIGATION BY TYPE IN NEW ZEALAND
Gun
Borderdyke Lateral & linear boom
Other or unknown
Pivot
K-Line/Long lateral Rotorainer
Drip/micro
