While the first season of their subsurface drip irrigation trial hasn’t gone to plan due to the wet summer and autumn, Cust dairy grazers Penny and Gary Robinson have established a good baseline for the next season of their trial.

While Cust dairy grazers Gary and Penny Robinson are disappointed not to have collected the data they were hoping for from their subsurface drip irrigation trial due to a wet summer, the couple have established a baseline for the next irrigation season which they hope will follow a more normal weather pattern to enable data collection.

Gary and Penny are participating in a farming innovation project, which examines how the next generation of farmers are using innovation to improve their farming practices. Waimakariri Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the Ministry for Primary Industries (MPI) for the project, with support from MPI’s Sustainable Food and Fibre Futures fund along with Environment Canterbury, Ballance, and DairyNZ.

The subsurface drip irrigation system on their two-hectare test block in Cust consists of a network of valves, driplines, pipes, and emitters that are installed in tape below the surface of the soil. The evenly spaced emitters slowly release water directly to the root zone of plants which differs from traditional irrigation systems that apply water to the surface of the soil.

At the beginning of autumn Gary and Penny invited Carrfields and Ballance to visit the trial block to take pasture samples which have been used to provide a baseline for the next irrigation season. Penny says it is great to have two key industry partners on board to provide technical assistance with the trial.

“We mowed five consistent strips of the same width and length of pasture for analysis in terms of yield and tonnage per hectare of dry matter. This has given us a useful baseline which we can use for the following season.

“Having Carrfields and Ballance involved in the project is important as they are both invested in farming innovations. Carrfields can see that subsurface irrigation is the future of farming and Ballance are keen to see how we can use subsurface technology to apply precise amounts of fertiliser to the root zone of plants.”

Now that Gary and Penny have their baseline figures established, they plan to do an on-farm comparison between their subsurface irrigated trial block and the unirrigated section of the block. They will also compare the subsurface drip irrigation system with the traditional sprinkler irrigation system operating in another part of their farm.

“We have learned how the system functions at a practical level and moving forwards we are hoping for a typical irrigation season weatherwise so we can get the data to share with potential customers and partners. Having a baseline already in place allows us to track our progress throughout the season and make those important comparisons to prove the benefits of subsurface irrigation.”

Penny says one of the unique benefits of subsurface drip irrigation is the precision control of the system which allows farmers to use their water resource more efficiently resulting in cost savings and environmental benefits.

“The exact amount of water is applied directly to the roots which means you are not using any more water than you absolutely need to because you rely on data from your moisture probes which makes everything that much more accurate.

“You are irrigating to scientific data, not to what your eye can see. The result is overall more stable growth with better quality plants and a much better use of your water resource.”

For the next irrigation season Gary says the focus will be on measuring how much water is used by the subsurface irrigation system, the pasture growth rate and measuring how many tonnes per hectare of dry matter can be removed from the trial paddock.

“While it hasn’t been an ideal season for a trial, we are hopeful that we will be able to gather the data we need next season, and we will be ready to flip the switch on the subsurface irrigation system as soon as the moisture probes indicate we need to start irrigating.”

Fernside farmer Julie Bradshaw and Flaxton farmer Stu Bailey were able to make better informed decisions for their farms after participating in a five-year National Institute of Water and Atmosphere (NIWA) co-innovation study.

Fernside dairy farmer Julie Bradshaw says sharing scientific data in a way that was easily
understandable and useful for farmers helped create close bonds between landowners and NIWA
scientists during a five-year joint co-innovation study.
Julie is participating in a six-month farming innovation project, which examines how the next
generation of farmers are using innovative approaches to improve their farming practices.
Waimakariri Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the
Ministry for Primary Industries (MPI) for the project, with support from MPI’s Sustainable Food and
Fibre Futures fund along with Environment Canterbury, Ballance, and DairyNZ.
“It was a reciprocal relationship between our farmers and NIWA. They had no experience of dairy
farming, but it worked because we were willing to listen to each other and NIWA had a genuine
desire to provide us with data that was practical and helpful.”
Fellow co-innovation study group member Stu Bailey, a fourth generation Flaxton dairy farmer, says
working with NIWA helped him to make better farming decisions, especially on irrigation.
“They developed an easy-to-use tool that helped us to do things better. Before the project we had
limited data, but we now have a much broader understanding of what is really happening under the
ground.
“In the past you would look at the top of the soil and think it looked too wet or too dry but actually it
could be a bit dry on the top and wetter underneath where the grass roots are, and you wouldn’t
know that unless you have the moisture probes to measure it.”
Stu says having access to a broad range of data has opened his eyes to how useful science can be
when it is used in a practical way.
“We are looking at other ways to use the information and having the data helps us to feel confident
that we are making scientifically based decisions. We have improved our irrigation infrastructure to
better meet the demands of the soil and the grass which means we are now using less water.”
Julie would love to see further studies conducted to gauge the benefits gained during and after the
project and she believes the project provides an excellent example for other groups who want to
successfully engage with farmers to improve environmental outcomes.
“The difference with this project was that NIWA were responsive to our needs, and we worked
together to understand what data would be most useful to help us meet environmental regulations
and how best to receive this information.

“For example, in the beginning the moisture capacity of the soil was extremely basic and displayed in
a percentage format and this was changed to a colour scale so we could see immediately where the
moisture was sitting in the soil.
“We want information that is easy to understand in a couple of minutes because we are so busy
working on the land that we don’t want to be sitting around reading long reports. We want to able
understand what we need to do and then go out and do it.”
Meanwhile, this season Julie has been improving the condition of the grass on her farm. A consultant
has conducted soil testing and provided insights into actions she could take to boost the nutrient
value of the grass.
“We are looking at adding different species to our grass, along with plantains and a different mix of
grasses to give us a wider spread.
“There is no point just adding more fertiliser if you don’t know where you sit – you have to consider
the environmental impact of your actions.”
Julie’s KiwiCross herd which is a cross between Holstein-Friesian and Jersey cows is currently ranked
in the top five percent of Canterbury herds for breeding and production and sits just outside the top
five percent at a national level. She is passionate about continuing to improve the value of her herd
through genetics.
“We have 99 per cent recorded ancestry and all our herd are DNA tested so we know exactly what
we have and where we should be heading. As a business it is about getting the most efficient cows,
and then breeding from those cows.
“All dairy farmers need to be taking action to have the best herd of cows because that is going to be
the reality moving forward. Cow numbers are already being reduced across Europe to meet tougher
environmental regulations and it will happen here too.
“The best thing to do is to start working towards your genetic metrics now, as it is not something
you can do in a year. It will take at least five or six years to get the best herd and we need to be
proactive about this.”

Gary and Penny Robinson with their children Harry, Charlie, and Olivia in front of their subsurface drip irrigation test paddock in Cust

A wetter than usual irrigation season has hindered data collection efforts for Cust dairy grazers Gary
and Penny Robinson. They had planned to collect data over the season from their subsurface
irrigation system and compare this with traditional irrigation methods. However, the couple have
still been able to prove the system’s water and power saving benefits on their two-hectare test
block.
Gary and Penny are participating in a six-month farming innovation project, which examines how the
next generation of farmers are using innovation to improve their farming practices. Waimakariri
Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the Ministry for
Primary Industries (MPI) for the project, with support from MPI’s Sustainable Food and Fibre Futures
fund along with Environment Canterbury, Ballance, and DairyNZ.
A subsurface drip irrigation system consists of a network of valves, driplines, pipes, and emitters that
are installed in tape below the surface of the soil. The evenly spaced emitters slowly release water
directly to the root zone of plants which differs from traditional irrigation systems that apply water
to the surface of the soil.
Gary says that while the unseasonably wet season meant that farmers didn’t require much water for
irrigation, the rainy weather stymied efforts to collect and compare data from their subsurface drip
irrigation trial block.
“This was meant to be our data collection season but with the significant rainfall events we have had
all season it hasn’t quite worked out the way we thought it would.”
Despite the uncooperative weather, Penny and Gary were able to gather information on water and
power savings during a drier period in the middle of the season.
“What we found was that over the drier period in December we only had to irrigate every fourth day
and with the emitters putting on two millilitres per hour we only ran it for two hours per day to get
our four millilitres.
“This equates to water savings of up to 25 per cent and you can take that water and spread it out
further over the rest of your land, so it is a much more efficient use of water.
“With the subsurface drip irrigation system, we are not wetting from the top but from under the soil,
so it stays wetter for longer which means you don’t need to irrigate as often, and you also don’t lose
any water due to evaporation.”

The couple also researched power savings and found that it was possible to save up to 50 per cent
on power usage due to the shorter operating time for the subsurface drip irrigation system.
“With a sprinkler system you need to keep it running 24 hours per day but because the subsurface
system doesn’t need to be running continuously you can make quite significant savings on power.”
Gary and Penny have secured another site for a subsurface drip irrigation trial at Angus Aiken’s 550-
hectare mixed cropping and finishing farm in Waiau. The plan is to have the irrigation system
installed in early spring.
Angus, who is a firm believer in technological innovation, says he is keen to see if the system can add
value to his farm.
“We have a limited water resource on this farm and if we can use it more efficiently and spread it
further that would be great. I am keen to make changes that preserve our soil structure, help to
manage nutrients, and improve our water use efficiency, while also improving our crop yield.”

Cust farmer Roscoe Taggart examines his parsnip seed crop which is bound for Europe

Investing in precision agriculture has provided Cust farmer Roscoe Taggart with environmental, social, and financial benefits that help to continuously improve his family’s 730-hectare arable and sheep operation.

Roscoe is participating in a six-month farming innovation project, which examines how the next generation of farmers are using innovative approaches to improve their farming practices. Waimakariri Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the Ministry for Primary Industries (MPI) for the project, with support from MPI’s Sustainable Food and Fibre Futures fund along with Environment Canterbury, Ballance, and DairyNZ.

At the start of the project Roscoe applied variable rate nitrogen fertiliser with nitrogen sensors attached to the roof of his tractor which has proven to be a game changer by applying the precise amount of fertiliser required for each paddock.

Having experienced the benefits of being able to apply variable rate nitrogen in real time, Roscoe has followed this up by grid sampling his farm in blocks to improve the efficiency of spreading fertiliser, while also reducing costs and environmental impacts.

“Traditionally we have done a standard soil test which is a transect across a paddock with about five or six samples. With grid sampling we are taking a sample every hectare and after we put this information into our variable rate spreader, we can spread our fertiliser in a much more educated way.

“This is especially important when you are doing your base application because if you get this right, you will get an even crop, and this has many flow-on effects.”

By applying his fertiliser in such a precise manner Roscoe anticipates growing crops that are more even which will make crop management much easier over the season.

“You will have everything happening at the same time in terms of the growth stages and a more even crop when it is time to harvest.

“Financially you are better off too as it makes your yield more even. You do have to invest more upfront with new technology, but it is well worth it when you consider the long-term benefits.”

The environmental and social benefits of applying the right amount of fertiliser at the correct time are also important to Roscoe.

“One of the biggest things we have got going on now in agriculture is our inputs and leaching. If we use science and technology to apply only what is needed to each paddock, then we are ticking boxes all over the place. Above all else, it is the right thing to do.

“From my perspective we need to prove that we meet the requirements to keep our social licence to operate and it is important to do the right thing on farm for our wider community.”

Fernside dairy farmer Julie Bradshaw is passionate about the ability of genetics to create the most efficient herd of cows.

Fernside dairy farmer Julie Bradshaw has applied learnings from a five-year National Institute of Water and Atmospheric Research (NIWA) irrigation study to make science-based decisions while also using genetics to improve her herd with the overall goal of reducing the farm’s environmental footprint.

Julie is participating in a six-month farming innovation project, which examines how the next generation of farmers are using innovative approaches to improve their farming practices. Waimakariri Landcare Trust (WLT) and Waimakariri Irrigation Limited (WIL) have partnered with the Ministry for Primary Industries (MPI) for the project, with support from MPI’s Sustainable Food and Fibre Futures fund along with Environment Canterbury, Ballance, and DairyNZ.

From 2016 to 2021 Julie and a group of five neighbouring farmers participated in a co-innovation study which provided landowners with real time data and forecasts to make science-based irrigation decisions.

The data included measured rainfall, soil moisture, soil temperature, drainage, and estimated evaporation as well as two, six and 15-day rainfall and weather forecasts.

Julie says the practical study gave each farmer a fantastic insight into their own land and irrigation practices while also providing a broader picture of what was happening in the catchment.

Having access to precise data has helped Julie and her neighbouring farmers to apply exactly the right amount of irrigation and fertiliser at the right time which helps to mitigate environmental impacts.

“It was amazing. We had so much data and information that we had never had before which has helped us make decisions about irrigation and fertiliser used that are backed up by facts and scientific data.

“Having the records also makes it much easier when it comes time for your FEPs and audits. We can show that we have been using our water resource correctly.”

All the farmers involved in the study were able to see each other’s data and this high level of transparency helped the group to understand what was happening in various parts of the catchment.

“We have always been very open. It is just information and data about water and getting to know more about other farms is helpful because we are learning from each other along the way.”

Although the study has ended, Julie still logs in to the group’s website most days to enable her to make accurate decisions about water allocation for the Cust Main Drain Water User’s Group. The group was established 25 years ago to manage water allocation during the irrigation season when water takes are restricted.

“It has been such a bonus to be able to see where everyone is sitting in terms of the moisture on their paddocks as this helps me to allocate the water more accurately to where it is needed. Not only do you see today’s moisture levels but you also get a future reading so you can see where things are heading.”

Last year Julie and her husband Peter received the Sire Proving Scheme Farmers of the Year Award from the Livestock Improvement Corporation (LIC). The couple have been working with LIC for 15 years and the award recognised their record keeping and commitment to having their entire herd DNA tested.

“We have a KiwiCross herd which is a cross between Holstein-Friesian and Jersey cows. I am really passionate about the ability of genetics to improve your overall herd quality. Having 99 per cent of the ancestry of the cows recorded is an immense help when doing the breeding.”

Julie believes that improving the overall quality of the herd means that if she needs to reduce her stock levels in the future, she knows exactly which animals have the best genetics to meet future farming limits. She is committed to using science to reduce her impact on local waterways.

“Genetics and DNA testing is so helpful when you think about the possibility of reducing herd numbers in the future. We must think ahead and use science to help us make the best decisions both for our business operation and for the environment.”

Throughout the course of the MPI innovation project Julie would like to learn more about genetics, while also improving the quality of the grass throughout the farm.

“We have three cows that LIC would like a bull calf out of so that will be an interesting process to follow.

“Another challenge is to improve the quality of our grass. With the colder and wetter spring that we had last year, followed by a cloudy and cooler summer our grass didn’t contain enough sugar and energy for the cows. We want to work on that throughout this project.”