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!

EM Surveying - The Uses

In the previous EM survey blog, I ran through the process of conducting the survey, this time I will go through some of the uses.

The data from an EM survey is very useful for irrigation in many ways. The topography data can be used for planning the pivot design itself with your irrigation provider for example working out tower spacing and pivot positioning. The angle of slope can be used to see if the pivot stays within design parameters for insurance purposes as well as design planning.

Figure 1: Contour map on top of elevation map

After the initial pivot or irrigation design plans, we can then look at the EM data itself to determine the amount of variability within the surveyed area. Within the PCT Gateway software we can look at the value and amount of the crop being grown on the area and the cost of installing variable rate irrigation (VRI). The software needs to know the average yield and value of the crop. That way using algorithms it calculates that by not over watering the heavier soli types or under watering the lighter areas you bring the crop yield on those areas up to the average. It looks at the reduction in variability by using VRI as opposed to a blanket application. In the example below the variability from using VRI drops from 30.4% to 4.68%. So, by using the average yield and the price we can see the payback vs the cost of putting VRI on your pivot.

Figure 2: Illustrating the payback from VRI, using an EM map. 

This model just looks at the costs vs savings of VRI from a production prospective. It doesn’t take into consideration savings from reduced water use, power savings, reduced track repairs etc, which will be in addition to this.

The next stage is to make VRI maps up for the pivot, using the different soil zones, predominately we use the shallow EM results. If the area has a lot of variation in topography we can also combine the elevation layers with the EM map to make an application map for the pivot. We can also use other elevation layers to achieve the best solution used for each specific survey, as required.

The map below, shows a three zone EM map, where  red is the lightest soil, green the medium textured soil and blue the heaviest soil. This has been combined with the slope map, where the darker tone indicates a slope of 0-5% and the brighter tone of colour areas where the slope is above 5%.

Figure 3: An EM map and slope map combined to make a VRI application map. Brighter red, green and blue indicate slope for the different soil zones. 

The EM zone maps can also be used for irrigation pod placement, as well as moisture probe placement. If you only have one probe under an irrigation management zone, you want to make sure its under the right area. I will discuss this in more detail in the next blog. In the meantime, if you have any questions about EM surveying please get in touch.

Chris Smith

Operations Manager Agri Optics NZ Ltd.

EM Surveying - it's that time of year again!

With all the early season rainfall we've had the EM Surveying season has started a lot earlier than most years. It's great in a couple of respects: 1) we can get across the ground before it all gets really wet (if that happens) and the potential to make a mess increases and 2) it gives you more time to analyse and incorporate the data into your decision making over the winter months. 

As we're already into it this year, we thought it was time to give you a reminder about EM Surveying and how it all works. Today you'll get the first of a two part blog looking at the process, what you get from an EM Survey and what it can all be used for. 

EM Survey – Part 1 - the process.

When we conduct an EM survey we are measuring the electrically conductivity within the soil profile, the values have close links to the soil texture properties, where clay gives a higher reading than silt that in turn gives a higher reading than sand. So, by driving over a block of land you pick up the differences in the soil texture at two different depths 0-50cm and 0-125cm. Other factors have varying degrees of influence on the readings such as soil bulk density and moisture within the profile at the time of the survey. High salinity readings can have a huge influence on readings, but this is only in specific areas of New Zealand. The EM data is logged using 2cm accurate RTK GPS, so not only do we map the relative changes in soil texture, we are also collecting valuable topography data at the same time.

Agri Optics' EM Survey setup with soil profile shown. The measurements penetrate 1.25m into the ground. 

We drive most commonly at 12m swaths across the area, but closer resolution can be used for more intensive situations such as viticulture. Once the survey has been conducted we write a report about the findings from the two different EM layers, we then zone the EM data up into different management areas and run topography generated maps. Once you have had time to read through the report we arrange a meeting to then run through the report with you in person if you so desire. We also supply the client with software to view the data on their own computers and look at the different layers plus make your own management zones if required. From this point we can then focus on the areas of interest for your requirements.

The survey data has many uses, depending on the farming type and location and includes but is not limited to the following;  being the basis of variable rate irrigation application maps, moisture probe placement, used in zonal soil sampling, in dryland farming areas knowing where to put your effluent, to varying your nitrogen use depending on the underling soil types and used for flood modelling. It can also be used in conjunction with other layers of data such as yield maps, biomass maps and as happens frequency used with the topography data. Over the next few blogs I can drill into more detail on these different uses.

The EM season runs form the end of irrigation in the autumn through to Spring, but from now onwards is the ideal timing. For more information on EM surveying or to book one in for this season, please contact one of the Agri Optics team. Cheers, Chris. 

Technology Transforming New Zealand Irrigation

The latest issue of the IrrigationNZ News (Spring 2017) features an excellent and in-depth article on how technology is transforming irrigation in New Zealand. Featuring six case studies from throughout the country describing the different technologies applied on each farm - from soil moisture sensors to weather forecasting options to automated irrigation systems "designed to deliver the right amount of water at the right time".

Many of the technologies discussed have been previously showcased on our H2Grow blog so if you are interested to find out more follow this link and turn to page 28 => IrrigationNZ News: Spring 2017

Overlooking the North Otago dairy farm run by Nick Webster part of the "Peter Mitchell and Nick Webster" case study discussing how they use Growsmart Precision VRI technology to improve their operation.

Shared by the H2Grow 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

EM surveying - Knowledge is Power... (and Potential profit!)

An Electromagnetic Survey is one of the key layers required on the precision farming journey. Precise location and understanding of soil types is a key piece of information in driving decisions around water use and nutrient placement. Not only can an EM survey be used to reduce water inputs it can form the basis of other decisions related to plant health, production and nutrient uptake. Turning the pretty maps into useful data requires some powerful software. That is where VA Gateway comes in. Gateway allows for in depth analysis of multiple layers, including Yield and EM. All Agri Optics customers have access to VA Gateway and AgCloud the online version.

With the software we create reports on the various layers of data collected. Clients get information on two EM soil profiles, one measuring the conductivity in the top 0-50 cm of soil and the other looking at changes in the top 0-125cm of your soil profile. Our report explains our findings on each layer with an explanation of what you are seeing. Depending on the variability arising from the survey, we then create different management zones based on the range in EM units. These zoned maps can then be imported into your variable rate irrigation (VRI) software if they are used for irrigation or into your VR seed drilling control box if you are using it for variable rate seeding based on your soils.

Figure 1. Top left is a shallow EM map and to the right of it a zoned map of that layer. Below is the same but for the deeper EM (0-125cm).

We also report on topography features. As we log the EM data at 2cm accuracy we are also mapping these features. This data set in its own right is very useful and gives you the surface characteristics of the area surveyed in the form of six additional maps, slope, elevation, landscape change, aspect, any depressions and witness index (which way water will move in a rain or irrigation event). This data can be a powerful management tool. The water movement models can help highlight potential areas of issue, so they can be addressed, be it nutrient movement or run off.

Figure 2. Gateway software generates water movement models based on the topography data.

The elevation data can also be used to create contour maps that can be used in the design stage of your centre pivot system, e.g. when calculating tower spacing's or to help with budgeting for any required earth works.

Figure 3. Gateway software can be used to create 3D contour maps.

We can also create moisture probe placement maps based on your EM and elevation data to find your optimum site within each management zone. These sites can also be used as ground-truthing sites with HydroServices neutron probe to put actual specific values to the different zones water holding capacities and then convert the EM map into a water holding capacity map.

A further report can be created to gauge the likely payback time from the installation of VRI based on your soil variability, the crop you are growing, its value per unit and the cost of your VRI system. This is proving very helpful for those who are unsure as to whether they have enough variability in the surveyed area to warrant VRI.

All our data is collected using strict protocols, with the highest standards in continuity and quality every time. This ensures our clients have powerful, solution-focused information. For more details check out our website www.agrioptics.co.nz.

Post credit to Chris Smith.

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

Event Reminder: B+LNZ South Canterbury Farming for Profit Technology Expo - August 11th

Farmers in Canterbury and North Otago don't forget to head along to the Phar Lap Raceway in Timaru tomorrow for the B+LNZ South Canterbury Farming for Profit Technology Expo.

There is a great line up of presentations including a number relating to precision agriculture and efficient irrigation. And if you would like to meet some of the connections and contributors to the H2Grow blog in person than be sure to grab a front row seat in the following presentations:

4pm - Variable rate irrigation and the latest irrigation technology from Lindsay, manufacturers of Zimmatic, Growsmart and FieldNET irrigation solutions.

4:30pm - The benefits of EM surveying and precision agriculture products and services offered by Agri Optics NZ.

For full details of the agenda click here.

... and I will give you a heads up that H2Grow will be kicking off an exciting competition from 1pm tomorrow. Entries can be made at the Technology Expo and online, so head along tomorrow or watch this space for more details!!

From your friendly H2Grow Team

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

Reduce the Cost of Nutrient Loss with Precision Ag (Part 1 of 3)

Precision Ag can help you in many ways with your Farm Environment Plan (FEP). Precision nutrient management, EM maps, topography data,variable rate irrigation (VRI) and moisture probes are all tools available to help you manage your FEP and mitigate any potential issues you may face - Reducing costs to your farming operation and the environment.

I will be looking at how each of these can help you over the next few blog posts (to make sure you don't miss out pop your email address in the "Follow By Email" box, to the right). In this first blog of three I am looking into precision nutrient management.

Improving Nutrient Management with Precision Ag

The objective here is to maximise nutrient use efficiency while minimising nutrient losses into water. This can be accomplished by looking at the nutrient levels in the soils themselves as well as monitoring the moisture in the soil profile to ensure you don’t leach nutrients out with over watering. Precision Ag can help you in several ways to achieve this, this week I will look at the nutrient levels themselves.

This is done through either grid or zonal soil sampling. Instead of taking one soil sample per field or block, you sample in a grid at a resolution of one site per hectare or take samples within each known soil zone from your EM survey. Whichever way the samples are collected the sites are geo-referenced that means you can go back to the same point every time you sample so you can see how you are managing your nutrient levels over a number of years. At each site 12-15 cores are taken and placed in a bag, labelled and sent off to the laboratory for that sampling point.

Picture 1: Geo referenced sampling points in a field.

When you receive the laboratory results, they look similar to those you normally get however the critical difference is they are all geo-referenced and are at a higher resolution i.e. one per hectare. The data received can then be processed to create a nutrient zone map; with nutrient levels grouped in ranges for the given area and given nutrient.  From that layer of data application maps are made to match the soil and crop requirements.  The main nutrients commonly applied using this variable rate method are potash, phosphate and magnesium as well as lime for pH.

Picture 2: A map showing the varying Olsen P values across a field.

By only applying what is needed where it is needed means you minimise any over-application of product with financial and environmental implications, and you also maximise the crops potential on a nutrient level. By using this method you can mine nutrient-rich zones reducing nutrient levels in those areas and apply only what is required elsewhere.

Chris Smith

Agri Optics NZ Ltd

International Recognition for Precision Ag Advocate

Here on the H2Grow blog we showcase leading edge precision agriculture technologies and practices often through case studies of growers achieving success through there application. But in today’s post we would like to showcase a true leader in precision agriculture – Craige Mackenzie. Craige is a leading advocate and role model within New Zealand, a pioneer in the adoption of precision farming techniques.

Craige has recently been awarded the 2016 PrecisionAg® Farmer of the Year. This is a huge accolade and NZ should be very proud that the award has gone to one of our own!

The PrecisionAg® Institute recognises outstanding people, programs, and organisations that are making a difference in the precision ag industry. Each year’s winners have devoted their careers to the technology that improves crop production stewardship, agronomy, and efficiency.

Craige and Roz Mackenzie at Greenvale Pastures

Craige’s focus has been on utilising precision agriculture systems to maximise nutrient and irrigation efficiency for improved farm sustainability, both environmental and financial.

Craige and wife Roz farm Greenvale Pastures, a 200ha fully irrigated cropping operation near Methven specialising in vegetable and small seed production. They are also 50:50 equity owners in Three Springs Dairies, a high-output dairy farm with 1,200 milking cows. Their adoption of precision ag technologies has resulted in improved seed quality and yield with reduced inputs.

The utilisation of Growsmart Precision VRI has led to annual water savings of 32% and resulted in vastly improved water management on their variable soils. Resulting in three years of no measured nitrate losses to the groundwater!

In this recent video Craige and Roz share some of their secrets to farming sustainably and profitably through by employing precision ag.

In 2010 Craige and daughter Jemma established Agri Optics Ltd., New Zealand’s first precision agriculture service company providing precision ag tools and services to NZ farming systems with a focus on field sensing (crop sensing and Electro Magnetic soil surveying) and spatial data management solutions. Agri Optics NZ is now recognised as New Zealand’s leading precision agriculture company. And are also coincidentally partners in the H2Grow crusade.

This post has been put together by Sarah Elliot (Lindsay NZ), and I would personally like to congratulate Craige for being recognised with this prestigious award - Congratulations!!

Managing Environmental Compliance with Precision VRI and EM Mapping

Farm Fast facts:

Farm Name: Seadown Dairies

Cows Milked: 620

Length of VRI Pivot: 565m

Production: 1705/ha, 278000 KgMS

Pasture Grown/Harvested: 17,000 KgDM /14,500 KgDM

Key Benefits from VRI system: Reduced track maintenance, reduced pugging damage less water wasted.

Sustainable farm management was a major driver behind Brendan Caird’s decision to install Lindsay Growsmart Precision VRI with FieldNET on his 565m pivot. A major feature of the farm is a spring fed stream that flows through the middle of the irrigated area of the property. Totalling an area of approximately 5 ha, the streams and springs add to the visual appearance of the property and have been fenced and planted into a riparian zone. However without VRI effective irrigation management would have been considerably more difficult. By installing the VRI system Brendan is now able to work around mother nature and reduce his farms overall impact on the environment.

Riparian Zone in the middle of the VRI Pivot

The costs of irrigating his races and tracks were also a big part of the equation.

“Stock flows better, track maintenance is reduced and water is not wasted on unproductive areas” says Brendan who uses VRI to improve the conditions on the farm races. Nearly 5Ha of the 93Ha irrigated area is able to be avoided which includes races and waterways which allows Brendan to utilise that saved water elsewhere.

With an allocation of only 3.2mm/ha/Day irrigation practices need to be as efficient as possible at Seadown Dairies to maximise water use for grass production. Brendan also finds benefit in the VRI system to help remove paddocks from the irrigation round that are set to be re-sown. In the case of the 2016 season Caird planted fodder beet and set an irrigation plan to avoid the paddock whilst it was being cultivated. You can see the effects of this below. The yellow is the paddock that was avoided. The pink is for zones that were a part of the avoid zones.

As Applied Irrigation for the season. Note the paddock in Yellow.

Agri Optics conducted an EM survey on the property and the major soil zones were able to be identified see (http://www.agrioptics.co.nz/portfolio/em-survey/ for more info). The next step that Brendan and his team are working on is to begin irrigating to the EM soil zone plan. With multiple soil management zones identified on the property the goal is to water according to the relative requirements of each soil zone. This is aided by soil moisture sensing equipment to give the exact time that irrigation is required. Further to this Brendan can also be sure that soils are not being overwatered and water is not being wasted which Brendan says helps make his farm environment plan more comprehensive.

Blog this week by Nick @ Agri Optics
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Your Precision Agriculture Specialists - NZ Fieldays - Site J41

We’re knee deep into NZ National Fieldays week and you may want to pack an umbrella or come and visit the Agri Optics tent where you will find the team of precision agriculture experts and shelter from the occasional shower.

Their combined knowledge from world leading variable rate irrigation (VRI) research projects and practical experience helping farmers on a day to day basis with electromagnetic mapping, soil moisture measurement and VRI solutions means you could not find a more qualified team to answer your precision agriculture questions!

Your precision agriculture specialists on site J41
Agri Optics - NZ Fieldays

Introducing the guys (from the left):

Chris Smith has over 20 years’ experience in farming, both in NZ and the UK Chris boasts a wide range of skills covering all aspects of agricultural management. Chris is the winner of awards in the UK for improved production yields, reduced overheads and a range of environmental schemes and enterprises. He moved to NZ in 2007 from the UK to manage a mixed 600ha cropping farm in Canterbury until late 2012. Chris has experience in EM Soil Mapping, a range of variable rate application technologies and has worked with on farm computer systems for over 15 years. In the UK Chris was involved from the early stages with variable rate nutrient application from grid soil sampling, canopy imagery and yield mapping.

Stu Bradbury graduated from Massey University with a Bachelor of Engineering with Honours in 2005. While studying, Stu and classmate George Ricketts set up Wheresmycows.com Farm Mapping. Following University they continued with GPS farm mapping, designing new dairy conversion farm layouts and constructing centre-pivot irrigators. The combination of mapping and irrigation led to the invention of Variable Rate Irrigation and in 2007 the guys set up Precision Irrigation. Stu has been involved in countless VRI research projects and offers VRI solution advice globally.

Paul Whitehead also graduated from Massey University with a Bachelor of Engineering with Honours in the same year as Stu. Through his study and on leaving university Paul worked as a design and service technician for John Whitehead Electrical. As Paul honed his mechanical and electrical skills engineering fertiliser spreading equipment amongst other projects his aptitude for problem-solving shone. This natural inclination for problem-solving has helped countless farmers in New Zealand and abroad. Paul doesn’t leave a stone un-turned in his quest to solve a problem, working under flood lights to make sure he doesn’t drive out the farm gate until your variable rate irrigation system is working just perfect.

Nick Evans graduated from Lincoln University in 2013 with a Bachelor of Commerce in Agriculture. He then went on to complete a Master of Management in Agribusiness in 2015. During his time at university Nick sought out varied practical work experiences ranging from dairy farming on the West Coast to a wheat harvest in Victoria, Australia. Combining these experiences with university learning has built a solid foundation of agricultural knowledge. During the course of his Masters Nick was exposed to Precision Ag and found it to be a fascinating area of agriculture that had great potential.

Combined the team are your precision agriculture specialists (if you didn’t already notice the signage). Chris and Nick hail from Agri Optics based in Methven, Canterbury. And Stu and Paul are your Agri Optics North Island counterparts. If you don't happen to be heading to the field days this year and would like more information visit www.agrioptics.co.nz.

Today's post come from those back in the office at www.lindsaynz.com.

Site J41 in all its glory!

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.

Managing Pivot Wheel Track Problems

While centre pivot track management is fairly routine for most growers, those working in more challenging paddocks often need to take extra measures to avoid creating deep tracks or getting stuck.

“During the design phase of a centre pivot is the most cost-effective time to manage tracking issues,” said Steve Melvin, Irrigation Applications Specialist with Lindsay Corporation. “However, there are steps growers can take at any time to help reduce tracking problems.”

Following good maintenance practices is the first and most cost-effective step in reducing tracking problems. Melvin suggests:

• Check the owner’s manual and adjust the tyre pressure accordingly. When the pressure is too high, the tyres will make deeper tracks and if it’s too low, the tyre may come off the rim.

• During the first pass of the year, run the pivot around dry on a day when the soil is fairly moist but does not stick to the tyres or squeeze out. These conditions are optimum for packing the soil in the wheel track. During the second pass, apply 6 - 12mm of water. This will help compact the soil and reduce the depth of the pivot track during the season. 

• Over-watering and keeping the irrigated area too wet often leads to deep tracking problems, so it’s important to maintain a good irrigation schedule. Apply the largest practical irrigation depth, without runoff, and allow the paddock surface to dry more before the next pass. 

In areas where conditions create significant problems, Melvin said growers have additional options, including:

• Adding a three-foot extension in the pivot pipe at the pivot point every other year, which allows the wheels to move out of the old tracks for a year. This gives the soil an opportunity to firm up before moving back the following year.

• Adjusting the sprinkler configuration around each tower to direct water away from pivot tracks or applying water after the pivot has passed.

• Integrating Variable Rate Irrigation technology (VRI) for pinpoint control of irrigation systems. With VRI technology, problem areas can dry out, reducing the depth of the tracks throughout the growing season. For more information visit growsmartprecisionvri.co.nz.

• Increasing tyre footprint by switching to larger tyres, NFTrax or radials to minimise the kg's per square centimetre the wheel puts on the soil.

To access the complete article that Melvin wrote about track management options, visit www.ksre.k-state.edu/irrigate/oow/p16/Melvin16.pdf.

For information about tracking solutions, including NFTrax, talk with your local Zimmatic dealer or visit www.zimmatic.com/tracking-solutions. 

This helpful guide to managing wheel track rutting has been adapted from a recent Zimmatic by Lindsay blog article (Managing Wheel Track Problems) and posted today by Sarah Elliot from Lindsay NZ.

Efficient water management = successful cropping season

The 2015/16 cropping season saw a year that required a large amount of irrigation across most of the country due to the dry weather. If you weren’t using spray irrigation, variable rate irrigation (VRI) or measuring your soil moisture you probably ended up either over or under-doing the irrigation required for your pasture or crops. The more efficient an irrigation system, particularly this season the better off you would have been with maximising your return times and applying the right amount of irrigation for each crop.

Following harvest for the cropping guys we’ve certainly seen that more efficient irrigation methods (pivots and laterals and VRI) coupled with soil moisture monitoring has resulted in both increased crop yields as well as more even crops, even in this tricky dry year that we’ve had.

At Greenvale Pastures this season Craige Mackenzie has seen a massive advantage in his investment in spray irrigation (1 pivot and 1 lateral) both with VRI and his soil moisture probes. Average wheat yields have been up approximately 3.5t/ha this season and ryegrass yields have been up approximately 800kg/ha. These quite large yield increases during a testing dry year show that good yields are highly achievable and in Craige’s case, that Precision Agriculture (PA) and the tools and technologies that are part of PA are helping him achieve this.

Wheat yield map - 2015/16 season

Assuming that 50ha of a farm was in ryegrass and 50ha was in wheat with these yield increases it would give an increased profit of $64,750 (assuming wheat is $370/t) for wheat and $100,000 (assuming ryegrass is $2.50/kg) for ryegrass. This averages an increased profit of $1,647.50/hectare. When put into perspective this increase in yield is enough to almost pay for a pivot a VRI system and EM Surveying in one year.

The other advantage of using VRI on cropping farms is that you typically get a more even crop which makes life far easier when it comes to harvest as the entire crop is mature and ready for harvest at once. This advantage is very hard to tie an actual cost/benefit value to however the feedback from cropping farmers to date is that this is worth a significant value to their enterprises and this differs from crop to crop.

Wheat (Starfire) on 7th January 2016 - Paddock 19 @ Greenvale Pastures

The challenge from here is to see how we can consistently keep these yields up for all crops and across all seasons while maintaining strong on farm profitability. From where we’re placed and with the experiences we’re having across a wide range of farms we see Precision Agriculture as the way to do this. It’s all about knowing your paddocks and your crops and mitigating the weakest limiting factor and working from there. For some it might be fertility, for others it might be variable soil types and irrigation but for all cropping farmers yield mapping should play a key part in this Precision Ag journey.    

Here’s a photo for a bit of yield motivation…what can you achieve in this coming season? 

Great yields in wheat - 2015/16 season @ Greenvale Pastures

You can also see more of what’s happening on farm at Greenvale and keep up with their progress on their Facebook page https://www.facebook.com/Greenvale-Pastures-Ltd-135453169954919/

If you have any questions on how you can get the most out of your yield data or where to start the Precision Ag journey please give us a call at Agri Optics (03 3029227) so we can help you get started in the most efficient way for your farm. Cheers, Jemma

EM values - What the data is telling you

An Electro-magnetic (EM) sensor generates a constant electro-magnetic field that penetrates into the soil profile. It measures the bulk electrical conductivity of the soil profile. As we conduct an EM survey the sensor is taking readings at two different depths simultaneously. These two depths are known as the ‘Shallow EM’ and the ‘Deep EM’. The depths the DualEM reads depends on the height the machine is off the ground. With our EM setup we are reading the soil profile depth of 0-40cm for the shallow EM and the deep EM at a soil profile of 0-125cm. So the deep EM values are the same as the shallow plus another 85cm deeper. This is why the deep EM readings are always higher than the shallow as it is reading that extra 85cm.

Figure 1: Shallow EM of the same area with values from 1.6-27 EM units (mS/m)

Figure 2: Deep EM survey values varying from 16-43 EM units (mS/m)

 In this survey the same features are showing in the shallow EM and deep EM results, however sometimes this is not always the case the deeper profile can have a different underlying soil type that the shallow EM doesn’t pick up but the extra 85cm of deeper soil does and it changes the overall structure.

Generally speaking and depending on what part of the country you are in and the time of year the survey is carried out amongst other things, we would class a range in EM in the shallow profile of 1-3 units as low variability, 4-8 units as moderate variability and over 8 units range as high variability in the shallow layer/soil profile. In the deep EM/soil profile layer a range of 1-6 would be low variability, 6-15 moderate variability and over that high. It is often dangerous to generalise like that, but it gives you an idea of the type of ranges we look at, and as previously stated there are a lot of other factors that determine if the readings are low, medium or high variability. You also have to look at the distribution of the values as well, if the majority of the values are within a certain range and a few rogue values outside that but on a minimal area of the total, then the range in variation may not be as much as it first looks. How much the variability is costing you in terms of blanket irrigation applications compared to variable rate irrigation applications be it water, seed or fertilizer is a subject for another day!

Also of note as an aside; is that with all our readings legend red is the lowest value and dark blue the highest. This does not mean that red is bad and blue is good, there are a number of factors that determine that, and there is also a climatic influence on what is good or bad, in a dry year the heavier EM areas would be better where you don’t have VRI, and in wet years the lighter areas with more free draining soils would be more favourable. Likewise in peaty acidic soils with high organic matter they would show through as the high blue EM areas and clay soils would show up as the lighter red soils on the map. So it is always worth taking samples as you conduct the survey to see what is affecting the readings.

For more information on EM Surveying please contact us at Agri Optics NZ Ltd.

Chris Smith.