Maximising the Value of Irrigation

The H2Grow Team are excited to introduce Carolyn Hedley as our guest contributor, it is with great pleasure that we can share with you her valuable expertise. Carolyn is a Soil Scientist with Manaaki Whenua, based in Palmerston North, and lives on a small Kairanga farm with husband, Mike. Carolyn has combined her interests in soil science, proximal soil sensing and precision agriculture with on-farm studies of precision irrigation and soil carbon mapping. She has led several nationally funded projects in irrigation and soil carbon, including current leadership of the MBIE funded programme “Maximising the Value of Irrigation”.

Maximising the Value of Irrigation  -  Carolyn Hedley

Early in the new millennium I found out about EM mapping and in 2004 published a method in the Australian Journal of Soil Research to rapidly EM map soil variability on a basis of soil texture. I realised that EM mapping was a really useful new technology to rapidly survey soil variability. The EM map had picked the difference between a Kairanga silt loam and a Kairanga clay loam, and this had management implications for the farmer because the heavier textured soil would compact sooner when grazed in wet conditions.

I could see great potential in this new technology and so embarked on a PhD in proximal soil sensing and this is when I started to relate the EM map to soil available water holding capacity and realised how useful this could be for irrigation scheduling. But critics commented that irrigation systems cannot irrigate to such a complex pattern (example shown in Figure 1 below). Enter Stu Bradbury and George Ricketts, who had worked with me on some EM mapping projects when they were students at Massey University. There was an engineering solution to this problem – control the sprinkler system on a pivot to irrigate to any pattern – which led to the development of the Precision VRI system. Precision VRI, the world’s first true variable rate irrigation system, turned the heads of the global irrigation giants and as a result Lindsay Corporation acquired the technology development company founded by Stu and George.

Figure 1: Available Water-holding Capacity map derived from an EM map for a 100-ha area irrigated by a VRI linear move irrigation system

There was still work to be done though and a proposal put to the Ministry for Business Innovation and Employment received six years funding in 2013 to further research methods to improve management of irrigated land. Now in its final year, the “Maximising the Value of Irrigation” programme has been able to refine methods to use proximal sensor data to create prescription maps for precision irrigation. It has developed soil and crop sensing methods that can inform in near real time the prescription map, and a prototype scheduling tool has been tested with participating farmers as a smart phone app. The in-field sensor monitoring methods have been used to support Lindsay further refine the software control features for the Precision VRI system, which is remotely managed through the FieldNET platform.

Ekanayake, J. and Hedley, C. (2018) Advances in Information Provision from Wireless Sensor Networks for Irrigated Crops. Wireless Sensor Network, 10, 71-92. 

Research into different soil management methods has identified correct tillage and soil surface management methods to store more water in the soil and reduce irrigation requirement and water losses. A spatial framework to run the APSIM model has been created to test the effect of different irrigation scenarios on yield, drainage and water use efficiency. Spatial-APSIM simultaneously runs the model for up to 1,400 grid cells for one irrigation system to compare results of different irrigation scenarios at spatial resolution < 50 m, over several decades.

The MBIE Programme “Maximising the Value of Irrigation” is now working closely with its industry advisory group to ensure that its findings are communicated effectively and to find ways to integrate new tools and support improved management of irrigated land in New Zealand.

Irrigation Evaluations (aka Bucket Testing) - Including tips for testing VRI systems

Spring is here but we are seeing all four seasons rolled into one some weeks which is not an anomaly. The soil moisture levels in our region have had a healthy boost in the last few days but if the media reports are true we may be in for a dry summer - please don't shoot the messenger, I'm only relaying what I have heard.

Should this transpire then that is even more reason to ensure that our irrigation systems are applying water as efficiently as possible so that we are maximising the amount of water applied that is available for plants to grow. An irrigation evaluation is a way to assess the efficiency and distribution uniformity of your irrigation system to ensure it is performing as expected.

An irrigation evaluation will help identify causes of any poor performance and (sometimes with the assistance of a qualified professional) show how these can be resolved. Increasing irrigation effectiveness and efficiency will allow you to grow more for less.

An irrigation evaluation (often referred to as a bucket test) is simple enough to carry out yourself, there are several good guides freely available to walk you through this process. For more information check out:

IrrigationNZ - Bucket Testing Resources
DairyNZ - Irrigation Evaluation Guide

The guides recommended above will walk you through how to carry out a standard bucket test however before you begin you need to consider any additional technologies that enhance your irrigation system. For instance if your system has variable rate irrigation (VRI) technology then you will need to take this into account when planning your bucket test. Lindsay NZ, the developers of the Growsmart Precision VRI system, have created a step-by-step guide that explain these additional considerations in more detail.

Growsmart Precision VRI - Bucket Testing Tip Card

If you are not in favour of the DIY irrigation evaluation option then consider contacting an accredited evaluator, this would also be recommended if your own test identifies potential issues that warrant further investigation. If you have additional technology such as a VRI system then ensure that whoever is carrying out the test is aware of this and that they carry out the recommended additional steps. If you need further help then contact your irrigation dealer, many dealers also have accredited evaluators on hand.

Irrigation system checks and maintenance should be undertaken at scheduled times over the irrigation season (the more hours your irrigator runs for the more regularly these checks should be carried out). Recommended irrigation system maintenance will be covered in more detail in the next H2Grow blog post, this will include a checklist that you can download and print off to help you with this task.

Keep an eye out for the next post or subscribe by entering your email in the box to the top right of the screen to ensure that you don't miss it!

Today's blog was written by Sarah Elliot from Lindsay NZ - I hope you have found it useful!

Rain gauges – why they're a powerful tool for your operation

Do you know how much rain has fallen on your farm?  Or on your block of land down the road?  Do you sometimes forget to tip out the rain gauge?  Accurate rainfall figures for farm records are becoming more and more important in this age of transparency.  Knowing how much rain fell on any given day on your own farm or on a particular crop will give you the ability to make more accurate decisions.  Telemetered rain gauges save you the hassle of manually reading the rain gauge and provide up to date data straight to your phone or computer. 

Rain gauges can be installed along with your soil moisture probe and positioned under the irrigator or installed in a dryland area.  Positioning the rain gauge under the irrigator enables you to monitor exactly what application depth the irrigator is applying.  Application depths can change as a result of adding extra irrigators to the system, blocked or broken nozzles and changes to system pressures to name a few.  Excessive application depths are expected to account for on average 10% of water losses on an average irrigation system, that’s wasted power, water and most importantly money.  Not applying enough water may result in yield losses and shallow rooted plants.    

A telemetered rain gauge installed under the irrigator will also enable you to see the application rate applied.  If it is above the rates described for your situation in the table below you may be wasting water.  

Agri Optics can add a rain gauge to your soil moisture system to help your decision making.  Ring us today to talk about the options for your farm. 

Agri Optics office: (03) 302 9227

Cindy Lowe 021 796 834 or cindy@agrioptics.co.nz

Email: info@agrioptics.co.nz

In the words of Rachel Hunter - it won't happen overnight, but it will happen...

Wasn’t the whole election one big roller coaster?  If we have learnt one this from this whole affair, it is that we are all very passionate about our water resources – not necessarily for the same reasons, but passionate none the less.

Regardless of who ends up running the country (at the time of penning this blog, Winnie was still  courting both the National and Labour parties), I think it is clear that public opinion will ensure that water management and associated policies will be addressed is some way, shape or form by the incoming government.  Given this, I think it is important (and timely) to look back and acknowledge where we have got too in relation to this, but also to look forward at where we can still go.  

The National Policy Statement for Freshwater Management (NPSFM) and Regional Plans

Most regional councils now either have notified or operative plans which outline their methods for addressing water quantity and water quality.  While no two plans are alike, the NPSFM requires limits are set, therefore, all plans do just that – they set allocation limits for surface and groundwater resources, as well as water quality limits.  It is the latter which takes various forms including property limits and/or catchment limits using Overseer, in stream water quality limits, and the development of the Good Management Practice (GMP) framework.    Many councils have also adopted the use of audited Farm Environment Plans to be able to monitor, measure, report and ensure that farms are meeting their environmental obligations. 

As with anything in life, good things take time.  Councils are in the process of rolling out and implementing these plans now.  The effects will not be immediate, but they need to be given a chance to actually work. 

It must also be remembered that for many areas, it is as much about maintaining the already good water quality that exists – this is not allowed to deteriorate.  For those few areas where improvement is needed, the plans bite much harder, and that it totally appropriate.

The fact that all of this has occurred seems to have been completely overlooked by many, and it’s not just politicians I’m referring too. 

How are we meeting our environmental obligations already?

Figures provided by Irrigation New Zealand show that since 2011:

·       

• $10 million invested in audited Farm Environment Plans;   
• $600 million invested by existing irrigators upgrading to modern, efficient irrigation systems;
• $18 million invested in precision irrigation technologies;
• $15 million invested in installing irrigation decision-making technologies;
• More than 24,000 kilometres of our waterways have already been fenced off to exclude stock at a cost of $220 million. 

As we continue to meet our environmental obligations, you can only expect these numbers to increase.  It is noted that this expenditure is all on farm, reinforcing the point that water quality will be addressed at the farm level. 

Looking Forward

Regional Councils need to continue to implement their plans. This may seem like an obvious thing to state, but it’s true nonetheless.  Consistent messages and enforcement from the regulatory bodies will be a must.

I believe that many farmers are on board with GMP (the on-farm practices) despite still being largely ignorant or merely confused by the new environmental regulations.  Education is still key to the success of this stuff, and that has to come from all involved – banks, valuers, real estate agents, farm advisors, customers… anybody involved with the farm.  And, many farmers are being innovative and taking up technology where it is available.  You only have to look at the statistics above regarding the investment to date in irrigation upgrades and precision irrigation technologies.  

And last, but not least, time, time, time.  To quote Rachel Hunter from her Pantene ad, “it doesn’t happen overnight, but it will happen”, and it is happening.  Get on board, and keep it up.

 By Keri Johnston, Irricon Resource Solutions

Phone 0272202425 or email keri@irricon.co.nz

Tips, Tools and Technology for Efficient Farming - Part 1

During winter the H2Grow team ran a series of workshops throughout the South Island titled ‘Tips, Tools and Technology for Efficient Farming’. These workshops were very well attended and the team thoroughly enjoyed meeting everyone and the wide-ranging discussions that were had.

For those that were unable to attend we do not want you to miss out, so over the next few blog posts we will be posting notes of the key messages from each of the presentations. These are only condensed versions of the main points so if you would like further information or have any questions then please do feel free to contact the contributors directly by either clicking on the photo widgets to the right of this blog, or use the links provided.

The first set of presentation notes briefly cover the following topics:

1. Why should we care about farming efficiently?
• Nutrient management - why are we doing this?
• Irrigation and nutrient management - how to they fit together?
2. Soil moisture and water use efficiency

You will see there are two copies of the notes, one for Canterbury and the other for Otago as the notes relating to the regulations between these two areas differs.

Nutrient Management and Soil Moisture - Canterbury

Nutrient Management and Soil Moisture - Otago

Both topics were presented by Irricon Resource Solutions, so for more information please fee free to contact Keri Johnston or a member of the Irricon Team.

The Ultimate Add-On for Cost Efficient Irrigation

Growsmart Precision VRI with FieldNET is the ultimate add-on for easy and cost efficient irrigation, Maniototo sheep and beef farmer Hamish Mackenzie says.

“It’s simple, easy to use and gives you heaps of flexibility. I can sort and upload a watering plan and set it going at the push of a button,” Hamish says.

Hamish Mackenzie uses Growsmart Precision VRI to apply the right amount of water, in the right place at the right time at Kyeburn Station

At Kyeburn Station, an extensive 3300ha sheep and beef property, 260ha of flats are irrigated. Half the area is watered by a 570 meter Zimmatic centre-pivot. It was installed with Growsmart Precision VRI in 2015 and in November 2016 was upgraded with FieldNET, a remote communication tool making it possible to control Growsmart Precision VRI from any internet-capable device. The limited cell phone coverage means Hamish is not set up for complete remote control but FieldNET has given him greater flexibility over irrigation. And he says the new updated system is far superior to its predecessor.

“I do all of my irrigation plans on the home computer. If we had reliable cell phone coverage I’d be able to send them remotely to the pivot but because we don’t I put them on a memory stick which I then plug into the pivot panel of the irrigator. It’s really simple and straightforward.”

The touchscreen panel allows farmers to easily make changes to irrigation plans out in the field.

This season the pivot watered 37ha of Relish red clover-based pasture; 28ha of lucerne; 12ha of barley; 17ha of swedes; and 7ha fodder beet. The patchwork of different crops, each with different watering requirements throughout the season could have made irrigation planning and management a headache. But the combination of Growsmart VRI and FieldNET made it surprisingly straightforward.

“You can add in as many different fields as needed, and alter the watering rates on each or keep them out of the rotation as required. That’s the beauty of VRI and FieldNET, it’s so easy to alter things.”
Installation of FieldNET was about $1,000 on top of the Growsmart VRI but he reckons he’s easily recouped the cost – and saved water. Efficient use of water is a number one priority given the region’s 500mm annual rainfall and extended summer dry periods.  Water is taken from the Kyeburn River, from a main race which Hamish shares with four farms. He has a 52l/s allocation but over the last year the combination of Growsmart Precision VRI and FieldNET has reduced pivot water use to about 43l/s.


“I’ve been able to cut back the percentage flow through the pivot in summer and we’ve been able to use the extra if needed for k-line irrigation. Also we’ve saved money because we’re not having to pump as much water and we don’t need as much pressure.”

Irrigation development at Kyeburn Station started after completion of tenure review in 2009.
“We surrendered 4700ha of hill country to the Crown in 2009 so we had to intensify what we were doing.”

The goal was to maintain the same number of stock units by ramping up production on flat country. They purchased some neighbouring land that was irrigated, and added another 100ha pivot. There is now 260ha under irrigation, of that 180ha is covered by two Zimmatic pivots, one of which has Growsmart Precision VRI and FieldNET.

“I will sometime in the future retro fit the older Zimmatic pivot with Growsmart Precision VRI as well. I think it’s really important given the push by regional councils to encourage farmers to use less water and become smarter with how they irrigate.”

Lindsay NZ

'Tips, Tools & Technology for Efficient Farming' - Workshop Series

Do you want to improve the nutrient and irrigation management on your farm but are not sure where to start? Come along to a free 'Tips, Tools & Technology for Efficient Farming' workshop jointly hosted by Lindsay NZ, Agri Optics New Zealand Ltd and Irricon Resource Solutions.

Over the course of the workshop we'll cover off a range of topics from nutrient management, irrigation management and hardware, precision agriculture and how these all tie in with farm environment plans for efficient farming.

Please use this link to register - Register me for a workshop please!

We look forward to seeing you there

Am I a Responsible Irrigator?

The current Government's focus on water as the way to double New Zealand's farm exports by 2025 is reflected in the increasing accessibility of irrigation to farms around the country. Although a resource consent may state a Farmers right to use this water to irrigate and an irrigation dealership would be more than obliging to install the hardware - this ability to irrigate comes with responsibility.

To achieve a high level of irrigation performance requires a well-designed, well managed and well maintained irrigation system.

Choosing an Accredited Irrigation Dealer will ensure that your irrigation system is well-designed and meets the Irrigation Design Code of Practice and Standards. To view the list of currently accredited companies, click here.

Once the system is up and running ensuring it is well managed and maintained is up the those that own and operate it. The following questions should be considered by all those who irrigate.

1. Does my irrigation system apply what I tell it to in a uniform manner?

Poor distribution uniformity and low irrigation efficiency costs money. An irrigation evaluation is a way to assess the efficiency and distribution uniformity of your irrigation system to ensure it is performing as expected.

An irrigation evaluation will help identify causes of any poor performance and (sometimes with the assistance of a qualified professional) show how these can be resolved. Increasing irrigation effectiveness and efficiency will allow you to grow more for less.

An initial evaluation (often referred to as a Bucket Test) is simple enough to carry out yourself, there are several good guides freely available to walk you through this process. For more information check out ->
- IrrigationNZ
- Irrig8lite
- DairyNZ

If you are not in favour of the DIY option then consider contacting an Accredited Evaluator, this would also be recommended if your own test identifies potential issues that warrant further investigation.

The Hydro Services Team carrying out an Irrigation System Evaluation

2. Am I applying the right amount of water to optimise growth and avoid drainage or leaching? 

Measuring and monitoring your soil moisture is the best way to manage your irrigation efficiently.  If you don’t know what your soil moisture content is then how do you know how much you need to apply? Without this information, you risk either under-irrigating which can affect plant growth or over-irrigating which can also be detrimental to plant growth and the environment. Both these scenarios impact profitability.

There are a number of options when it comes to measuring soil moisture, choosing the best option for your farm and then ensuring it is giving you accurate information however cannot be covered in one paragraph. There are many posts already on H2Grow that discuss this topic, use the “WHAT ARE YOU INTERESTED IN” menu to navigate to these, or subscribe so that you do not miss out on these in the future.

3. Is my irrigation system working as it should, and will it continue to do so in the long run?

Irrigation system checks and maintenance should be undertaken during the off-season and at scheduled times over the irrigation season (the more hours your irrigator runs for the more regularly these checks should be carried out).  Recommended irrigation system maintenance will be covered in more detail in the next H2Grow blog post, this will include a checklist that you can download and print off to help you with this task.

Keep an eye out for the next post or subscribe to ensure that you don't miss it!

Introducing: SARAH ELLIOT

I considered starting this post to introduce myself boasting my passion for New Zealand agriculture - but how often do you read that statement and dismiss it much like you dismiss the over-use of superlatives in rural advertising?

So why is agriculture in NZ so important to me?

My fondest memories of growing up on our sheep and beef farm in Waitotara (South Taranaki) are “working” on the farm with Dad; riding shot-gun opening gates, feeding out, chasing sheep in the yards, probably just being a general nuisance. With endless area to explore, countless animals to play with, green grass and glorious mud your perspective of farming as a child is sublime!

My enthusiasm to participate in rural community events also grew from a young age. I credit this to the fantastic and friendly people in rural communities!

Working as a Jilleroo on Meda Station, a 1.25 million acre Brahman cattle station in the Kimberley’s 

By my latter years of secondary school when I was browsing university brochures I was drawn to the agricultural courses. But rightly or wrongly the school career guidance suggested with my exam results I should extend myself so enrolled into a Bachelor of Technology majoring in Product Development. I graduated with honours and was awarded the 2004 Product Development prize for my final year project with renowned NZ company Gallagher.

Summer university employment tracking milk losses in the Whareroa Fonterra plant one year and manufacturing TechnoGrazing™ system hardware for Kiwitech another also grew my appetite for solving challenges and looking for better solutions.

But what does this have to do with a blog aiming to help farmers improve irrigation efficiency?

After several years working abroad, when the opportunity came up to work with a team of guys who had just commercialised the world’s first true variable rate irrigation (VRI) system I felt it ticked all the boxes for me. I was going to be using my skills and experience as a mechanical design engineer to develop cutting-edge technologies to benefit the people, industry and environment that I love.

John Wright and I at a field day on his property, Wainono Dairies. John and his wife Sarah were early adopters of the Precision VRI system.

I have now been working in the irrigation industry for over five years and my primary role has been introducing farmers to Precision VRI technology and working with them to get the maximum benefit for their farm. I have had the pleasure of working with leading dairy farmers from NZ and Australia, poppy growers in Tasmania, onion producers in South Australia, turf growers in Queensland, cropping farmers, sheep and beef farmers from small scale to large. What strikes me as common to all the farms is that they can have the best technology in the world, but it won’t make a scrap of difference unless the person pressing go understands “why”. And this is the reason why I shoulder-tapped some people who know some things about efficient irrigation and together we formed H2Grow.

I also have a selfish agenda in wanting to increase knowledge of better, more efficient farming practices…  

My husband and I own and run Waikora Station, a 2333ha hill country property in the Hakataramea Valley, South Canterbury. It’s been a tough two years due to extremely dry conditions but experiencing this has grown my appreciation of the challenges faced as farmers. Like many other farming families we hope that one day our son may have the option to take over if he wants, but to make this possible it has to be sustainable (another currently on-trend word for you). And it doesn’t take long to realise how the consequences of our decisions affect the economics of our operation and impact the environment where we live and the community we live in.

Hamish and I on our farm, Waikora Station, in the Haka Valley

Sarah Elliot

Improving Irrigation Efficiency for Only $50 cont.

Here is the much anticipated second installment from the Improving Irrigation Efficiency field day run by The Waihao Wainono Group and Morven Glenavy Irrigation. Dr Anthony Davoren, renowned Irrigation Consultant with Hydroservices, shares how drainage through the soil profile can be measured. With this key piece of information we can improve our irrigation management, and know when to turn the irrigator on (or off) to ensure all irrigation that is being applied is going to benefit the grass or crops we are growing.

Thank you to Dr Anthony Davoren, Waihao Wainono Group and Morven Glenavy Irrigation.

Improving Irrigation Efficiency for Only $50

Dr Anthony Davoren is renowned as one of New Zealand’s leading irrigation consultants, establishing Hydroservices in 1983. If you have a question about irrigation management, soil and soil water assessment or surface and groundwater water resources then Tony will have the answer. What sets Tony apart is his practical, hands-on approach and the way he communicates information in a way that farmers can easily understand and relate to… I mean how many other speakers will you find presenting from a hole in the ground!

The Waihao Wainono Group and Morven Glenavy Irrigation recently hosted a field day focusing on improving irrigation efficiency. H2Grow is lucky enough to be able to share with you some short videos from this day. In the first in this series Tony explains how the root depth of the pasture or crop you are growing should be considered when deciding on the most appropriate soil moisture measuring equipment for your property.

Considering Root Depth when Measuring your Soil Moisture Levels

Keep a look out for the next video in this series where Tony explains how to measure drainage so that you can better manage your irrigation and prevent irrigation water, and nutrients, draining through the soil... and his top tips of how to greatly improve your systems irrigation efficiency for as little as $50!

Thank you to Dr Anthony Davoren, Waihao Wainono Group and Morven Glenavy Irrigation.

Reduce the Cost of Nutrient Loss with Precision Ag (Part 3)

In the last two blogs we looked at how Precision Ag can help with managing the nutrient and moisture levels in the soil profile. This blog looks at how an EM survey can assist in relation to the physical characteristics of the land for your farm environment plan.

As an EM survey is conducted, the readings are logged by 2 cm horizontally accurate RTK GPS. This allows us to not only build a great picture of your soil profile but also the surface of the area surveyed as well. This in its own right can be a very powerful tool for overall land management and also the farm environment plan. As the flow of water can cause the movement of soil and nutrients.

With this layer of data we can make 3D contour or water flow maps. So you can see where water will move in a rain or irrigation event and where potential areas of soil/nutrient issues may occur, so buffer zones may be necessary to mitigate this potential problem.

 

Picture 1: 3D elevation map showing the potential water flow across the area.

Our software platform, VA Gateway, can model the flow of water and we make an animated model of how the surface water will react over time. On the first image (picture 2) below you can see the surface water after a rain event then moving down the images how the water moves from the higher area and ponds in others. This sort of information is of great use to the client for highlighting potential issue zones.

Picture 2: Simulator showing the water flow after a large rain event.

Picture 3: The water is flowing from the higher areas.

Picture 4: The water is ponding in the low lying areas.

With variable rate irrigation application maps on ‘hilly’ land we can combine the EM and slope maps, to take into consideration the severity of slope over the EM. That is to say it may be a soil type that requires a higher water rate but when you take into consideration the degree of slope, then higher application rates would be moving down the slope as well infiltrating the soil profile, so therefore a lower application rate is needed on the steeper sloped areas to reduce the chance of runoff. By managing the potential flow of water across your property you are also managing the movement of soil and nutrients.

 

Picture 5: At the top left the EM zone map, on the bottom left the slope map. On the right the two maps have been combined to form an application map using both characteristics.

In Picture 5, on the right side is the application map where is red low EM, green Medium EM and blue high EM - the matt colours indicate low slope, the bright colours higher slope.

So with the use of Precision Ag you can gather very comprehensive maps showing the levels variability in nutrient levels, in soil characteristics and in topography for your property. By measuring these variables you can then monitor them and manage them, which are prime requisites for your farm environment plan.

Chris Smith

Agri Optics NZ Ltd

Reduce the Cost of Nutrient Loss with Precision Ag (Part 2 of 3)

In the last blog post we looked at nutrients and how Precision Ag can help with your Farm Environment Plans (FEP). This blog post looks at how an EM survey can help with identifying your soil types for your Farm Environment Plan.

An EM survey illustrates the relative variability in soil characteristics including soil texture that can be potentially related to water holding properties within that soil profile, this can help you manage water application through the use of variable rate irrigation technology. When combined with the use of soil moisture probes you have the data and technology you need to be able to retain nutrients within the soil profile itself. 

EM surveys can be ground-truthed to find the correlation between the EM value and water holding capacity (WHC).  From that you can create a WHC map and site-specifically place moisture probes to monitor the soil moisture levels within each identified zone.

Ground-truthing sites are identified within each zone (shown on the left). The graph illustrates the correlation between the EM values and WHC in the top 55cm of the soil profile for this paddock.

In the image above we can see the correlation between EM value and WHC at this site has an R2 of 0.97 (R2 quantifies goodness of fit. It is a fraction between 0.0 and 1.0, higher values indicate that the model fits the data better). We can then use the equation in VA Gateway, one of the PA software platforms supported by Agri Optics, to create a water holding capacity (WHC) map out of the EM values map.

The EM map converted into a Water Holding Capacity map

This water holding capacity map can then be used in conjunction with soil moisture probes and VRI to maintain the moisture levels between field capacity and critical moisture. This not only reduces any potential yield loss from moisture stress but it also ensures that you aren't saturating the soil profile, and therefore avoid leaching nutrients out of the root zone.

It’s all about balancing crop requirements, real-time moisture levels, rainfall (when it comes!) and application rates with irrigation return times as precisely as possible to keep everything at an optimum level.

An AquaCheck soil moisture probe graph showing soil moisture levels and how they are affected my irrigation or rain events on this soil profile.

As can be seen above by keeping the moisture between upper and lower readily available water levels you ensure yield isn’t compromised and eliminate leaching. The rooting depth used for the probe profile can be tailored to the crops specific needs on the moisture monitoring website.

Next time we will discuss how the EM maps and topography data can help you with your FEP.

Chris Smith

Agri Optics NZ Ltd

Variable Rate Irrigation and Soil Moisture Management - Introducing The Kowhais

Name: Tom Macfarlane

Farm: The Kowhais

Type: Intensive grazing

Location: Raincliff

Total Area: 800Ha

Total Effective Area: 655Ha

Area under VRI: 86Ha

AquaCheck soil moisture probes: 6

Annual Production: 1000 Lambs, 1500 deer and 1000 bulls

Average Pasture Production: 9500kgDM/Ha

Efficient meat production is the goal for Raincliff farmer Tom Macfarlane. After taking over the property 3 years ago Tom is striving to lift production whilst doing so in a sustainable manner. The Opuha River runs along the boundary of the property and this means that Tom is wary of the impact that his intensive farming operations may have on the environment.

Finishing 700-800 bulls before their 2^nd winter on farm requires a high level of feed intake and the bulls need to be growing every day. The techno system is intensive and requires daily management of multiple small mobs of animals. Juggling the stocking rate according to the feed supply and demand requires effective pasture management strategies to maintain quality throughout the spring and summer.

Water use efficiency is also high on the agenda at Macfarlane’s as water for the properties irrigation system is supplied from the often restricted Opuha Water scheme. Roughly 180 Ha is under irrigation on the property and his pivot and lateral, both with Growsmart Precision VRI, water an area of 86 Ha. Irrigation is also applied through K-Line, hard hose gun and Roto-Rainer systems which cover 31.8, 32.5 and 56 Ha respectively.

The Kowhais EM Zone Map to be used with VRI

The Growsmart Precision VRI really proves its worth when water restrictions kick in as Macfarlane is able to use planned moisture deficit management to water different areas of ground cover at reduced rates. When water is short the fodder beet is watered less frequently to free up more water for the higher quality pastures. Macfarlane also is able to reduce applications on heavier soils to spread his water further. All of this is enabled by the combination of EM Soil Surveys, AquaCheck soil moisture sensors and Growsmart Precision VRI.

The installation of AquaCheck soil moisture sensors has added to Tom’s suite of decision support tools. Tom is now aiming to forecast potential pasture production from soil temperature and moisture data received from the AquaCheck probes. This will enable him to better decide how many head of stock he will be able to carry and will aid in planning for the upcoming season.

The combination of AquaCheck moisture probes and a Growsmart Precision VRI system enables Tom to better manage his irrigation scheduling. The ability to see what is happening to soil moisture and applying the correct amount of water at the correct time has benefits in terms of sustainability and pasture growth. Pasture growth is critical in Macfarlane’s techno beef system where pasture utilisation needs to be kept as high as possible. With potential harvest efficiencies of up to 85 to 90% the cost of overwatering is not just limited to run off and nutrient loss. Pasture damage caused by heavy 18 month old bulls has a significant impact on the level of wastage and future pasture production. The AquaCheck probes will allow Tom to see how soil moisture is tracking and can alert him to when soil moisture rises above the pasture damage threshold. 

With one eye always on efficiency at The Kowhais the use of variable rate irrigation, EM soil surveying and AquaCheck soil moisture probes has given Tom Macfarlane the tools to help improve efficiency and productivity. Watch this space to see how things evolve at The Kowhais.

The Road to Complete Control from your Mobile Device

Here's an insight to the development pathway from the world's first true variable rate irrigation system through to the release this year of Growsmart® Precision VRI with FieldNET® - complete remote pivot management, with VRI control, monitoring and reporting. 

For more information visit precisionirrigation.co.nz/fieldnet.

This video clip has been shared with you by Sarah Elliot from LindsayNZ.

Irrigation NZ Conference Summary

The Irrigation NZ Conference was held in Oamaru from the 5^th to 7^th of April. There was a huge range of speakers and presentations all relating to different aspects of the industry. Some of the important and recurring topics are summarised below.

Irrigation has benefits to communities and the environment.

The pre-conference tour took a bus load of delegates on a tiki-tour through the Waitaki valley to see first hand the irrigation schemes that draw water from the mighty river. It is readily apparent that irrigation water has benefits to farmers and community.  An example being a storage pond which is held in a trust to allow the public to use it for recreational use. A great example of the community and irrigators coming together to prosper together.

MGI Intake off the Waitaki River.

Also highlighted on the trip was how irrigation can have benefits to the environment.  The frequent droughts experienced by the Waitaki Valley prior to irrigation meant that rabbits and dust storms were free to wreak havoc on the area. Now, with irrigation, soil is no longer lost in howling Nor’Westers and improved soil structure has resulted in reduced sediment loadings in water ways. This draws some similar parallels to Keith Cameron’s talk at the PAANZ Conference (see: http://www.h2grow.nz/2016/03/inaugural-paanz-conference-summary.html)

The future is a scary place…

Synthetic meat and massive urban greenhouse skyscrapers are set to be realities in the future. The value and limited supply of the world’s natural resources was something that really hit home in Julian Cribb’s talk and it gave serious weight to the fact that efficient irrigation and water use is extremely important.

Another guest speaker, Peter Biggs detailed the concept of the volatile, uncertain, complicated and ambiguous world that we live in today. Complexity and uncertainty are two concepts that are a big part of the irrigation scene in New Zealand. How do we keep an eye on the future when such complex issues confront us at home on a daily basis?

Engaging with the public is important for success.

Nicky Hyslop, Chair of INZ made us aware of something we are all possibly guilty of. Not listening when we should. The idea that more often than not we just need to “shut up and listen” when dealing with the public on issues related to irrigation and agriculture and go forward in a dynamic, proactive way. The key message being that we must “engage” with the public rather than lecture them if any change is to be bought about.

 

Waitaki Irrigators Collective to bring together all irrigators in the Waitaki Valley

Management and measurement to improve efficiency.

The growth of technology in the sector is seeing efficiency gains left, right and centre. From improved efficiency of infrastructure that delivers water to the farm gate to the use of VRI and soil moisture management, irrigators have plenty of scope to lift performance. The level of data that can be easily captured from an irrigation system such as; flow, pressure and energy used is high. Not only can irrigators make use of this data to reduce energy costs but also water use efficiency. Dan Bloomer presented on how simply it is done with 2 dozen buckets to actually measure what water your irrigator is putting on the ground. Ultimately what gets measured gets managed.

This weeks post was bought to you by Nick Evans of Agri Optics. To find out more about Nick or to get in touch with Agri Optics check out our website: http://www.agrioptics.co.nz/meettheteam/ 

Irrigation – Grow with the Flow

Next week the historical Waitaki region will be host to the 2016 IrrigationNZ conference, IRRIGATION – GROW WITH THE FLOW. There is a variety of keynote speakers from all around the world and a jam-packed programme of interesting presentations and workshops. I have picked out a few presentations and workshops of mention that may be of interest to the H2Grow followers. For the full programme click here.

We all know information is key and many of the posts that you may have read on H2Grow share the many different sources of data that you can gather, monitor and measure in relation to irrigation. But with so many options for irrigation management you may be left wondering which are going to give you the greatest benefit. I’m hoping that this workshop may shed some light…

WHAT TO MEASURE MONITOR AND HOW TO MANAGE DATA FOR IMPROVED IRRIGATION PERFORMANCE – ENERGY, PRODUCTION & ENVIRONMENT presented by Ian McIndoe (Aqualinc) & Steve Breneger (INZ)

And…

REGEN WATER – USING SCIENCE, INFORMATION AND SOFTWARE TO MANAGE IRRIGATION presented by Bridgit Hawkins (Regen)

And furthermore…

REAL-TIME SOIL MOISTURE MONITORING IRRIGATION DECISION SUPPORT SYSTEMS presented by Pierre Roudier, Carolyn Hedley, Jagath Ekanayake, and Joseph Pollacco (Landcare Research)

Coincidentally the team presenting this later topic from Landcare Research have been involved in many variable rate irrigation and electromagnetic surveying studies.

Once you have monitored, measured and made an informed decision of when, where and how much to irrigate you may be after a tool that allows you to implement your irrigation schedule. This next workshop should enlighten you on the latest options to do so…

COMPLETE CONTROL FROM YOUR MOBILE DEVICE presented by Stu Bradbury (Lindsay NZ)

And lastly, one of the most topical irrigation related discussions at present (second to the tough economic conditions for many) is…

HOW REGULATORS AND FARMERS ARE DEALING WITH IRRIGATION AND NUTRIENT USE EFFICIENCY – THE CHALLENGES AND THE OPPORTUNITIES

Once we’ve been educated by the educators and experts I thought interesting food for thought would come in the form of…

OUR FUTURE – WHAT WILL IRRIGATION LOOK LIKE IN 2050? This will be presented by Christopher Neale (Director of Research, Robert B. Daugherty Water for Food Institute, University of Nebraska). Currently development of remote irrigation management technologies and pinpoint irrigation control systems seems to be the focus but what will be next? And what will an irrigator look like when my son is the age that I am now?

I hope that provides a small taster of some of the information that will be on offer. As well as the presentations there is a exhibition with over 35 stands where you are able to talk to those in the irrigation industry including irrigation designers, engineers, suppliers and support companies.

Lindsay NZ are at site 17, we will be unveiling two exciting new product releases (which I will share more information on next week), but we look forward to seeing you all there.

If you are not able to make it to the entire conference there is a Farmer’s Trade Afternoon, on Tuesday 5th April from 3:30pm–5:30pm.

Today's post has been written by Sarah Elliot from Lindsay NZ.

Inaugural PAANZ Conference - Summary

Precision Ag in New Zealand is finally starting to gain a bit of traction in NZ & this was seen last Friday by:

1)      the fact that the Precision Ag Association of NZ (PAANZ - www.precisionagriculture.org.nz) ran their first conference

2)      the  number of attendees that came from far and wide to attend & learn

Firstly, I’d like to congratulate the PAANZ committee on organising a well-run event with some thought provoking topics and speakers. I’m going to run through a bit of a summary of the day in terms of what was covered and some ideas to ponder.

Andy Macfarlane from Macfarlane Rural Business kicked the conference off to a start with a general overview of NZ ag and where we’re at in terms of water, nutrients and farming within limits. One of the key points from his presentation was that “Good Management Practice (GMP) is a given – everyone needs to get there NOW!” GMP will evolve and is not a fixed point. ‘Good’ will also not be good enough, farmers will need to be ‘great’ to keep ahead of the game and ensure long term farm viability. Precision Ag is going to be integral going forward to achieving this.

Some Key Principles for mitigating N leaching

1. Measure before you apply – need to know what you’re dealing with so you can make the right input decision.
2. Use nitrogen (& water) interceptors – roots, different crops etc
3. Smaller and often applications are better than large amounts and less often
4. Do not put nutrients where you don’t need them (use targeted application technology – Precision Ag)
5. Apply less urine or less nitrogen concentration in urine
6. Increase nitrogen utilisation in gut to decrease output of nitrogen
7. Less water drained = less nitrogen leached
8. Integrated farm systems approach required to achieve long term desired outcome
9. Validation of science needed both at research level and on farm

Keith Cameron, Professor of Soil Science at LincolnUniversity also posed a sound point that irrigation, even though it might be controversial in some areas and need better management allows increased N uptake as the plants are actively growing and not under stress, therefore less leaching of nitrogen results. Is there a case for environmental irrigation? Especially in summer dry areas? He also pointed out that we need to look at plant uptake as a mitigation strategy for decreasing nitrogen leaching. Catch crops following/during winter grazing is likely a good way to achieve this and studies have shown that this can be by between 20-40%.

While we all know that nitrogen itself is a key part to the nitrogen leaching discussion, in irrigated Canterbury and other parts of the South Island managing soil moisture is key to effective nitrogen management. Dr Tony Davoren from HydroServices spoke on this topic and highlighted the following:

• Measuring and understanding your soil moisture is key to good irrigation management and reduced leaching
• No drainage throughout the growing season from pivots if managed well – the same can’t be said of other irrigation systems with high application rates in particular
• You need to measure soil moisture at and below the root zone. Firstly to understand your plants requirements, and secondly to know and be able to prove that you aren't leaching and wasting water
• It’s also important to measure soil temperature as this is also a factor when scheduling irrigation and brings in the ‘farm systems approach’ that Andy talked about by looking at multiple factors.

As the focus of the day was mostly looking at how nitrogen leaching could be reduced using Precision Ag (PA) techniques there wasn't a lot of emphasis on other areas, however some were slightly touched on. These included Ian Yule (Massey University) talking about the economic impact of poor spreading pattern and that it could cost a farmer on average $45/ha if his spreading CV was at 20%, however CV was likely to be nearer 30% when out in the field. At costs like this we obviously need to get our spread pattern accurate before we start doing variable rate fert. Accuracy is key to everything in Precision Ag. The benefits of ‘All Paddock Soil Testing’ was highlighted for reducing paddock to paddock nutrient variation and pushing pasture yield along on dairy farms.

There were a vast array of topics covered during the day, stretching further than just nitrogen leaching and it was truly encouraging to see such a good turn-out of interested people to this inaugural event as well as the robust debates and discussion that went along with it. It’s truly heartening to see NZ farmers and industry pushing the boundaries and meeting NZ farming targets using tools and technologies that are already out there today. The future is very bright for NZ ag and coupled with all of the emerging technologies and the science to back these up I feel very encouraged about the position of the New Zealand farmer. Now to get everyone dabbling their toe in the water of Precision Ag…

~ Jemma

Workshop: Technology to Reduce N Leaching

If you're under pressure to mitigate N leaching and improve efficiency and profitability on farm - then the PAANZ Technology to Reduce N Leaching is for you!

Note registrations now close on March 18th. 

Register: paanz-workshop.lilregie.com