Technology – the biggest change

Technology has been the biggest and most exciting change in the irrigation sector and much of this was initially triggered by the water metering regulations 2010. There were a wide range of viewpoints around metering, some supportive of its compulsory introduction, others arguing against it and stating that real-time measurement of data was too costly and there was no value. This certainly made for some interesting conversations during the policy design phase!

Real-time measurement is now a given for all water takes, noting there are still some regions resisting, but they will hopefully see sense in the near future. While this provides information to the regulator for compliance purposes, its main benefit has been for improved irrigation performance. Sensor data used for irrigation decision-making, such as soil moisture or climate, can be easily telemetered with the water meter data in real-time. This was the game changer: ‘If I have to do this water metering thing I might as well make the most of it.’

Recent student programmes in Canterbury and Hawke’s Bay have shown irrigation decision-making technology uptake rates are now over 70%. However, there is the issue of technology rejection yet to work through, as there are too many businesses out there selling sensors as opposed to providing what is required. Despite this, you can visibly see the practice change when you drive between Christchurch and Ashburton soon after a rain event – 10 years ago most would still be irrigating, whereas now there are only a handful.

Over the next five years technology will likely take over the human decision-making altogether. Variable rate irrigation systems for precision application is now commonplace, and it will not be long until autonomous irrigation systems informed by artificial intelligence and remote sensing will become the new norm.

As part of this change it is likely soil moisture sensors will soon also become a thing of the past. Soil water budgets adjusted by remote sensing data, for example where actual evapotranspiration is calculated at the sub-paddock scale by the normalised difference vegetation index (NDVI), infrared (IR) and other measurements, will soon become commercially available in New Zealand and make the application of precision irrigation much easier as a result.

The rapid pace of technology change is why we need to make sure any future regulations, whether market, collective or regulator-led, focus on quality monitoring systems being in place for irrigation decision-making and not compelling the type of monitoring system to be used.

Farmers adopting technology is a real example of how change can be successfully implemented over a short timeframe, bringing with it multiple benefits for all New Zealanders.


Schemes of the future

There has been massive change in the irrigation scheme infrastructure space over the last 10 years. Alongside over $1 billion being spent on modernisation (open channels to pipes and manual to automated control systems) there has been an increasing level of professionalism within the sector.

The investment in piping and automation has enabled on-demand water delivery, which in turn has allowed investment in more efficient irrigation systems on-farm. New Zealand is now one of the most advanced countries globally for scheme infrastructure automation – to the extent that where international experts, scheme and farming leaders from overseas are now regular visitors, and they are always amazed by the innovation they see.

A decade ago all irrigation schemes were both governed and managed by shareholder directors and racemen were the only staff. Almost all the large schemes now have general managers, operations managers and environmental managers alongside scheme operators. They have become much more aware and future-focused as a result. Independent directors are also now common, and boards largely focus on governance.

Scheme amalgamation is likely the next step. We have already seen this starting to occur in Mid and South Canterbury. Over the next decade I predict this will continue resulting in four super schemes managing over 60% of New Zealand’s irrigation. Contrary to the current government’s rhetoric, scale is a good thing. It allows for investment in water supply efficiency and also more easily provides support for irrigators who need to improve their environmental practice.


Irrigation system change

Of New Zealand’s now 800,000 ha of irrigation, less than 6% is left flood irrigated. There has been a huge (in excess of $1 billion) investment in upgrading to modern spray and drip systems over the last decade. Over 60% of New Zealand’s irrigated area is now under center pivot, lateral and solid set for pasture and cropping systems and drip-micro for vegetable and permanent crops, which is unprecedented globally.

Of the modern irrigation systems drip-micro is by far the most efficient. New Zealand’s dominant norwesterly weather pattern can significantly impact on the efficiency of spray systems, as the application is blown off target changing the intended distribution pattern.

There are a number of pasture and cropping trials currently occurring with drip, and to date these have proven to be extremely successful, providing the laterals are spaced correctly. The question is, over the next 20 years will drip begin to replace modern spray systems in New Zealand as it has in places like California and Israel? While the capital cost is double, the potential benefits from reducing nitrogen loses could more than make up for this.

The other system change that is now being explored in New Zealand, and one that we are behind the eight ball on internationally, is the use of fertigation (the injection of fertilisers into an irrigation system). We have made mistakes with fertigation over the past decade, trying to mix irrigation and fertigation events together when the two should be treated as separate applications.

The lack of a bulk liquid fertiliser supplier has also had negative results. As a consequence, urban myths began to circulate that fertigation does not work in New Zealand, despite the body of international research. However, evidence from some preliminary trials this season is showing production levels can be maintained using 30% less nitrogen – this comes from moving to a ‘little and often’ approach. The capital cost of installation also looks like it will be recouped within a season. A Master’s project through Lincoln University will investigate the pros and cons of fertigation in much more detail over the next two years.


The environment

Both the national and regional discussions on how to manage nutrient losses from farming started in earnest a decade. Water quality had been declining for a number of years and it would be fair to say some farmers had pushed their farming systems beyond sustainable limits. As a result, the first Freshwater Management National Policy Statement was promulgated in 2011 and we now await the fourth update to this with a degree of trepidation.

The limits regime we all now operate under is a result of the National Policy Statement. However, it is the implementation mechanism – the introduction of audited Farm Environment Plans (FEPs) – that focuses on the widespread adoption of good farming practice which is starting to make a difference. The declining trend seems to have halted in many areas and we are seeing early signs of water quality improvements. While this is a huge step in the right direction, and will help irrigators plan for regulatory change, good farming practice will not be enough in some at-risk catchments.

In these cases the only way to solve the problem is to look at it holistically as a catchment – and as a community. Recent overseas study tours to both Australia and the US have highlighted the need to bring catchment scale infrastructure into the mix, while also spending time clearly identifying the issues before coming up with solutions.

In many cases it could be more cost-effective to buy out and retire land or allocations in a particularly sensitive part of the catchment, rather than place blanket requirements across everyone. We also need to work through how we fund such solutions so that everyone who benefits contributes, as this is currently the elephant in the room.

To really get the water quality management system right we need to target the actual problem in the most cost-effective way. We have been very farm-focused in our thinking to date, e.g. ‘you will all decrease your nutrient losses by 20%.’ This is largely driven by the focus of the Resource Management Act 1991 – individual effects-based. However, I am not sure this is either fair or targets the problem. I am concerned that new regulation, which is being influenced strongly by the environmental lobby, may ignore a more holistic and constructive approach.


Public perception

It has been an uphill battle getting the good word out there about the significant changes occurring and the world-leading nature of the New Zealand irrigation industry, but progress has been made. The level of understanding about the benefits of water to agriculture are much more widely understood than a decade ago – so much so that freshwater rights are an increasingly political topic.

Much can be done if more farmers are willing to ‘put their head above the parapet’ and tell the story of their journey of change. This is not a fanfare, ‘look what we’ve achieved’, as very few will believe this. It is a humble, ‘this is what we now realise and this is what we are now doing to address it.’ Industry organisations can only do so much in this space as it is authenticity that is required with the wider public.

Telling the story of change from the grass roots is much more powerful than CEOs and board chairs constantly fronting the media. The only way to help educate the media, politicians and the public on the contribution irrigation makes to New Zealand is to share the story of how and why, and explain the important role of guardianship that farmers are now embracing.

It has been a decade of unprecedented change. The previous government was looking for a step change and they definitely got it from the irrigation sector, and the new government is starting to realise the change that is actually happening out there.

We have moved into a community-led environmental limits framework and the available water for irrigation is increasingly managed on an ‘as and when’ basis informed by data from an array of sensors. Automation is here and artificial intelligence is not far away.

The current water management regime in New Zealand needs a change of emphasis so that community-based solutions, including infrastructure, are considered alongside or preferably before regulatory constraints on-farm. We also need to become more spatially and temporarily aware in our solutions, as many of our water quality issues will not be effectively solved without a targeted approach.

Finally, the farming community needs to stand up and talk openly about what they are doing to better manage water. The public does not want to be told the problems are fixed; they want to know that the farming community are once again the guardians of New Zealand’s unique environment.


Facts about irrigation in New Zealand

  • We only abstract 2% of our water resource in New Zealand and irrigation makes up just over a 1% of the consumptive use
  • We irrigate around 800,000 ha of land, and around 60% of this is for dairy, 20% for cropping and 5% for fruit and wine. The remaining 15% is used by sheep and beef farmers for pasture and cropping
  • Around 30% of dairy production comes from irrigated properties, 50% of arable crops and nearly all vegetable and fruit crops are irrigated
  • Modern spray irrigation systems make up just over 60% of the irrigated area, only 6% still remains as flood irrigation and the balance is older spray systems.

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