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Angus Kebbell talks to a Hurunui River dairy farmer and DOC's chief scientist about how land use changes brought by irrigation are changing the river catchment water quality

Angus Kebbell talks to a Hurunui River dairy farmer and DOC's chief scientist about how land use changes brought by irrigation are changing the river catchment water quality

Factum-Agri is a weekly podcast dedicated to New Zealand’s Agriculture industry produced by Angus Kebbell. Key areas of focus are - industry analysis with key stakeholders, policy makers, engagement with farmers and producers, and working to close the rural/urban divide.


We are looking at what farmers are doing to improve their businesses, their biodiversity, their land use and their wellbeing.

Over the past few weeks, we have been looking at farming after the Kaikoura Earthquake and how communities have rallied together and come out the other the end of such a devastating event.

Earthquakes and climatic factors have a significant impact on New Zealand’s farmers and producers, and all rural areas in New Zealand have a similar vulnerability to earthquakes and there are many lessons to be learned for farmers around the country from the Kaikoura earthquake.

Over the last couple of weeks Factum-Agri has been discussing the economic and social benefits and challenges of irrigation.

This week the environmental implications of irrigation are being discussed with farmer Nick Ensor and Ken Hughey who is the Chief Science Advisor to the Department of Conservation.

Ensor farms 520 ha in the Hurunui River catchment as an irrigated dairy unit that has been converted from sheep & beef.

Irrigation has enabled all-year grass growth although water access is only required in the September to May period. Converting to dairy allowed 90 ha of hill country to be retired into forest and wetlands, and now less than half the farm is used directly for dairy livestock, the rest for dairy support so that the unit is now fully self-contained. Erosion susceptible areas are now no longer under farming stress.

The farms now also supports more employees, going from one as a sheep & beef unit to four as a dairy unit.

Ensor welcomes the focus on standards and improvement. But he does chafe with the heavy-handed focus of the bureaucratic regulation that seems to overlook the big picture gains being achieved in favour of form-filling processes.

Hughey is at the top of the chain of regulators in the Hurunui River catchment, and a Professor of Environmental Management at Lincoln University. He is also well connected to the Wellington policy makers.

He is responsible for implementing the Fresh Water NPS in the catchment.

He sees much progress, but says that any further fresh water degradation is no longer acceptable to anyone.

He says irrigation can work well for overall water quality, and the irrigation scheme companies play an important role in setting standards and driving improvement among their customer/shareholders.

He is also watching a growing movement of farmers who are voluntarily applying covenants to their land to protect biodiversity.

While Hughey doesn’t think farmers are being unfairly targeted by the national fresh water standards, he does agree urban voters and Wellington officials don’t give farmers credit for the progress being made.

He points out that Christchurch City essentially refuses to manage severe water degradation from excessive concentrations of Canada Geese in its waterways, a problem that spills over to all of North Canterbury. And then these voters blame farmers who actually are managing such problems successfully.

In the end, Hughey says farming, including irrigated farming, will be the engine that pulls New Zealand out of its economic recession. And farmers need to be rewarded when they do that while improving the natural environment.

Farmers work hard, they love the land and care for whatever is produced on their properties. There are many things for farmers to think about whether it be drought, market conditions and farm gate returns, and increased pressure from the public or policy makers.

This podcast series tells the stories of these challenges.

Angus Kebbell is the Producer at Tailwind Media. We are hoping this will become a regular series.

We welcome your comments below. If you are not already registered, please register to comment.

Remember we welcome robust, respectful and insightful debate. We don't welcome abusive or defamatory comments and will de-register those repeatedly making such comments. Our current comment policy is here.


If you are irrigating on light gravel soils, nutrient loss has to be a problem. The knee jerk reaction from the public must also be concerning.

As to NZ Ag exporting and solving all our problems, I think that is little more than a pipe dream. Competition in export markets is going to be fierce.

Just one example of our new world, US flour consumption drops to 30 year low.

There's a webinar on Monday on soil science that you might enjoy, Andrew - registration here;

I'm happy with where my soils are heading, mostly because looking over the fence, Im miles ahead of the neighbours who are on better soils than me. I think I can really take this a lot further, I had some soils issues mainly acidity, i put tons of lime on over two years and the Mg turned to custard. I've blown 50k to get where I am ( perhaps a bit more), now I'm just going to tweak things. I'm going to plant a lot of legumes and also doing strip sowing.
It's really expensive when you start and it's hard to hang in there.
Confidence in the future is evaporating with all that's happening, so time to go low cost. My grass is bolting even with all the frosts we have been having, that and we are still in this dry spell although a green one.

Sounds great, you're already there ... yes time to go low cost.

Water is the key ingredient for our future in both the urban & rural zones. Both groups need to pull their socks up as far as the sustainability of this precious resource goes. For me, storage is a key component is this discussion. Whether for drinking, irrigating & yes, even for energy purposes, water is the one thing we need to get right. For all the talk & telling off in recent times, we simply do not have enough water storage. What was enough 60-70 years ago is not any more. We have huge expectations for all our types of water & the city dweller has their part to play by having water storage solutions as part of their city residences. It should be mandatory in my book, but as is often the case these days, council greed gets in the way.

The Amuri basin, water from the Waiau (of which is the picture - Mouse Point Road, up from the Red Post), is a great success of what was a community border dyke scheme, transitioned to pivot.

The farming systems before (sub clover browntop & south down lambs) were harder on soils than current.

Scientific references please, otherwise you are just a FF party political broadcast.

Yes knowledge is important.

Top level. As this addresses the...
he does agree urban voters and Wellington officials don’t give farmers credit for the progress being made.
Intellectuals and Society not only examines the track record of intellectuals in the things they have advocated but also analyzes the incentives and constraints under which their views and visions have emerged.

Detail level: 2 steps.
1. Grasslands papers, many and Large Herds Conferences,
For example Grasslands 1994:
Building a solid foundation: sulphur phosphorus and potassium requirements for sedimentary soils of North Canterbury
Roberts, Webb, Morton, O'Connor, Emeades.
2. Known truth. People, we are living it.

Andrew- you are right about irrigating light gravel soils, but when farmers in Amuri started irrigating nutrient loss was unheard of. Not all the basin is light, some of it is quite heavy. As HT says, the basin is now highly productive, a far cry from brown top and 12kg lambs. If irrigated dairy farming does nothing else it will fund the establishment of irrigation schemes that will enable future farmers to take advantage the best market that the combination of their soils, climate and water will allow. Just because irrigated land is presently used for dairying does not mean that that will always be the case. I would wager that in 50 years most of the better Canterbury soils under irrigation will be used for crops such as potatoes or the like.

I believe that we can change systems so nutrients are used by plants and not wasted, i just don't know how to get there, I also think this needs to be led by farmers trying new things, not people 'who don't know what they are doing', ie councils.
I don't know yet how to capture those nutrients but I think the problem will be worse with intensive cropping. I am worried about sensationalist articles by journalists who don't know what they are talking about but get mainstream coverage.
It's finding how to grow plants that can utilise the N as far as I know clover can produce more N than we could ever apply, for me clover = bloat. Im working on the problem, it's slow as I have to wait for next season all the time and they are always different, dahm it.
I'm wondering how much you can drop cow numbers but increase per cow production, a win win.

Andrew, re capture of nutrients, deeper rooting plants like plantain and chicory are helpful, as is Lucerne, but in most cases Lucerne also equals bloat. I had the same problem with bloat when farming in the NI, and ended up running hoggets ahead of cattle in order to take the sting out of the clover. So far (13 years ) I have had no trouble with bloat on irrigated pasture in Canterbury. Re clover growth I have observed that the more urea I apply to old cocksfoot pasture the more clover appears. Re cow numbers, inferior genetics are a characteristic of an expanding industry ( think sheep during the skinny sheep era of the 70,s ) and now that cow numbers have stabilised the opportunity is there to work on improving per cow performance via genetics. For most dairy farmers costs are per cow and returns are per hectare, so improving genetics gives the win/win you refer those people who are experimenting with regenerative farming may stumble onto something in the nutrient space.

give Graig Smith seeds in Ashburton a ring and try some Sainfoin, it's a non bloating legume, very popular in the UK and Oregon.

Andrew there is a very simple solution to your problem of bloat when growing clover/legumes and that is salt. Potassium and sodium work together in a balanced soil but if potassium is the only one you have been applying and sodium is low the plant will be taking up far to much. If you do pasture tests look at the DCAD and if your pastures are on the high side you need to add sodium to pull the high anion/cation ratio back. Its sad that the 2 big fert co dont advocate using sodium to stop bloat cause its a very easy solution. I suggest you apply 80kg/ha to start and then come back 20kg/ha each year to end up with maintenance of 20kg/ha every year you apply fertilizer. Hope this helps with clover/bloat problem and you can crank the clover up to fix nitrogen for you.

I've never heard of this before, thanks I will do some research. It was such a problem we gave up on lucerne. We had a bad grass grub problem and our pasture ended up all most all clover.
I have added salt before, and I have used salt blocks( bloat blocks work really well). Im getting into some strange things the neighbours are giving me odd looks, some paddocks stayed green this year in a 1 in 50 year drought.
Isn't it amazing how little we know about soils, yet spend thousands each year on the advice of a young soil rep paid on commision.

Haha you are so right about the pretty young girls as fert reps now. Very little knowledge and a vehicle, laptop for orders, phone cause that's all they need now. Send me an email if you like and I can send you some info on some of your issues.

Farmers work hard, they love the land and care for whatever is produced on their properties.

Sounds like a party political broadcast. In fact the whole article can be summarised thusly: Heroic farmers set city greenies right.

Have you ever stepped foot on a farm? Or are you just another armchair "expert" throwing rocks from the sidelines? Enlighten us with your extensive knowledge of all things farming! It always amazes me how much comment there is on farming (in all media) but very little of it is from actual farmers. Most just don't have time to pontificate all day! As the saying goes " never let the facts get in the way of a good story(rant!).

the problem areas around here re almost entirely corporates or very large farming operations pushing boundaries, the regional council won't act unless embarrassed and shamed into action.

This really bugs me as the council then over reacts and jumps on all of us.

I hear you Andrew. I have no love for corporate farming either. One of the worst is Landcorp! And we all pay for their stupidity!
My point was though that farmers are constantly bagged by people who know absolutely nothing about farming - only what the read by other commentators, the likes of Fish & Game etc.

We have these problem areas that get ignored, like NAIT, doesn't work but we keep up appearances. We should make tag manufacturers pay for lost tags, they are the ones failing.

Another Muldoon Think-Big Legacy that died and rose again - a gift that gave

The Amuri Irrigation Company is a private company which does not publish financial accounts - what is that scheme valued at today?

In 1987 the Amuri schemes were valued at $22-26 million by NZ Treasury
The Farmer Consortium insisted that these works had no value if irrigators could not afford to pay the water charges and the scheme was closed down and rejected any valuation that was above nominal figures with a write off of taxpayer funded investment.

When the larger Lower Waitaki scheme was sold for $1 million, the Consortium knew their scheme was worth less. The Amuri Irrigation Company Ltd (AIC) was formed in 1990 and the Government agreed to sell the three Amuri schemes to Amuri Irrigation Company Ltd that same year.

1987, there were a couple of other things going on Ag wise.
People had corriedales, trading losses and water charges.
Only a minority number of people there now, were there at the beginning. The turnover has been large.

Amy Adams
Central Plains Water Scheme

Conflicts of Interest - July 2019
Amuri Irrigation Company Ltd

Last year we went through the Waitaki Valley to look at the Waitaki scheme
What a mess - have a look at the photo below from the ODT
Guess how much that's worth and the land value enhancement to local farmers

Waitaki Irrigation Scheme

The controversial irrigation pipe between Kurow and the Waitaki Dam will eventually be placed below ground level. The Waitaki District Council has given the Kurow Duntroon Irrigation Company a deadline of September next year to complete this work. Sections of pipe either side of the Kurow Cemetery were installed above the ground as part of the company's $45 million upgrade and expansion

The upgrade you refer to involved putting the water into a pipe and delivering it under pressure to scheme subscribers, where previously delivery was via an open race. My understanding is that in order to meet contract deadlines the installers chose to site a small section of pipe above ground, contrary to consent requirements, where the intention was always to come back and remedy the situation once the irrigation season was over. The Kurow Duntroon scheme is not synonymous with the Waitaki scheme - it is merely a small offshoot that operates in the same area. The Waitaki scheme is one of the most mature and settled schemes in NZ, and could not in any way be described as a mess.

When a $100 million irrigation scheme runs past your dry-land farm it's value is enhanced even if you dont hook up to it - read the last paragraphs of the following article by Guy Trafford irrigated land $44000 versus dryland $17000