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.

Celebrating 10 years of Irrigation Innovation

It’s a classic story of Kiwi innovation.

One summer’s evening in 2004, two Massey University engineering graduates, Stu Bradbury and George Ricketts were working a summer job assembling irrigators on the South Wairarapa farm of Brian and Jo Bosch. 

Over a cuppa, Stu, George and Brian discussed the challenges on the Bosch’s farm caused by the limitations of the existing pivot irrigation system.

“Where the pivot went over the races was wet and mucky,” says Brian.  “We were also getting a number of lame cows, who got wet feet and bruising on the muddy race.”

Brian Bosch on his Wairarapa dairy farm

Blanket irrigation was the problem. They needed a way of irrigating specific areas that needed it but keeping vulnerable parts such as the race dry.

Back then nothing on the market could manage the water flow in targeted and controlled quantities, to specific parts of the farm depending on topography and soil type.

“We saw wet areas where crops weren’t growing, and dry areas without much water. So there was an obvious need for a system to specify where you needed water and how much,” says Stu.

Before long George had the solution and in 2006 they began developing the prototype that would become Precision VRI. VRI stands for variable rate irrigation, ensuring precise amounts of water or nutrients are delivered over multiple crops, soil types and terrains.

To make best use of the technology on paddocks with variable soil types and terrain electromagnetic (EM) soil mapping is recommended. EM mapping measures soil conductivity which is an indicator of soil texture (along with other characteristics) and therefore soil water holding capacity. The Precision VRI system can be easily programmed using the FieldNET app to customise irrigation according to the EM map.

The system can be used to ensure that only the areas that need water, get water, and at the right levels.

Over the past decade Precision VRI has enabled New Zealand’s farmers, food producers and agricultural contractors to achieve better results, driving efficiencies and saving money – to the benefit of agribusiness, not only for dairying, but in sheep, beef, horticulture and arable farming.

In 2011 global agribusiness leader Lindsay Corporation acquired the NZ company WMC Technology Ltd under which the Precision VRI technology was developed. Through doing so the not only gained the rights to market the award-winning technology but also provided significant backing for George, Stu and the team to continue developing irrigation solutions.

From the archives: George and Stu at a farm mapping job in 2010 (above). Stu, George and Paul (below) receiving the Supreme Award at the Manawatu Business Awards 2010, WMC Technology Ltd also won the Innovation Award and the Workplace Health and Safety Award.

“We are working on new iterations of the software,” says Stu.

“Now, everything needs to be mobile-friendly so that is where our efforts are focused.”

Future plans to market the system internationally will give farmers world-wide the advantages experienced by New Zealand farmers using the system.

To find out more about the Growsmart Precision VRI system call 0800 438 627 or visit www.lindsaynz.com.

Precision Ag update - a UK & Europe perspective - Part #2

The second part of the CB Norwood’s Precision Ag tour was spent in Europe with machinery companies. First, we visited Vaderstad at Hogstadvägen in Sweden, then Lemken in Germany, Horsch in Germany and finally New Holland in Belgium. All these companies looked after us very well, for which we were most grateful.

Arriving in Sweden, the first thing we noticed was how dry it was and how it was reflected in the stressed crops we saw travelling to the Vaderstad factory. The same could be said of the crops we saw in Germany, but to a slightly lesser extent.

Vaderstad showed us a vast range in cultivation and drilling equipment but from a precision ag point view I was most interested in their E system and Seed Eye technology and what it could mean to us in terms of precision seed placement. The sensors installed in each seed tube on the drill form the basis of the Väderstad SeedEye. This gives the ability to register each seed that is metered and drilling can be controlled down to the exact number of seeds per square metre. 

Figure 1: Vaderstad SeedEye system

Next we went to Germany and visited Lemken, where we looked about their HQ and factory. Again, a lot of cultivation and other equipment but more of the traditional systems with various plough options. However, they too have very accurate seed planting options which would be very useful for precision seeding.

Figure 2: Lemken precision drill seeding system using air pressure

When we got to Horsch we had seen how the other companies worked but I was surprised at the level of trial work and other extensions Horsch were working on and how they were thinking outside the box. They were doing trials on the effect of difference press wheels on root establishment, different row spacing, seed rates and fertiliser rates down the spout. It was a very comprehensive setup and very interesting results.

They ran through their different drilling options including the Avatar with 3 hoppers to put different seed rates and types such as hybrid wheat in different zones plus fertiliser in the third hopper.

Figure 3: The effect of different sowing techniques on root development in Oil Seed Rape

Figure 4: Horsch Avatar drill with 3 hoppers

Figure 5: Trials on seed and fertiliser rates at different row spacing

 All the systems we saw lent themselves well to Precision Ag and accurate seed rates per metre, which can be used in combination with your EM maps, or other sources of spatial data such as yield maps or satellite imagery.

On the second day at Horsch we had a good look around their sprayers and the very impressive pro plus boom system that followed the crop canopy at a height of just 30cm with various nozzle options including 25cm spacing that reduced the effect of wind speed on your spraying window, giving more spray days which is a very useful feature everyone needs.

Figure 6: Top spec nozzle system with 4 nozzles every 50cm and 2 nozzles at 25cm in-between

Figure 7: Off to see the sprayer demos at Horsch

 Michael Horsch also touched on the next stage in their sprayer development, with autonomous machines that sprayed by themselves and the cameras learn the weeds they see in field and can map them. All very exciting and not that far away. High spec sprayers are very useful for variable rate PGR’s (plant growth regulators) or liquid nitrogen for example.

The final company we went to see were New Holland, with their machinery from combines to Foragers. Using their Precision Land Management system on control and measure. Yield maps are the starting point for a lot of people’s journey into Precision Ag.

Figure 8: New Holland combine open for investigation!

If you have any questions or want anymore detail on what we saw, just get in touch. 

On a personal level, it was great to see what machinery is available and what we could do with it in the Precision Ag space and to see that we’re not far behind the northern hemisphere in terms of PA adoption, and in some instances, are actually leading the way.

Chris

Precision Ag update - a UK & Europe perspective - Part #1

Having just spent most of June in the UK and Europe on a tour organised by CB Norwood, looking into Precision Ag, I thought I’d give an overview of what I saw of interest.

The tour group consisted of a great mix of farmers, contractors, CB Norwood’s managers, from both the South and North Island, Tim Myers (CB Norwood CEO), myself and was run by Paul Collins (CB Norwood Partnership Development Manager) - hats off to him for an excellent job managing the whole event and his team back in NZ.

The first week was spent in the UK, going around farms and visiting the Cereals event near Duxford. There was a real mix of farms from the traditional Estates, to new corporate farms less than 10 years old with huge areas 15,000+ hectares. From the precision ag point of view, it was interesting to see that we are all using the same technologies but for different reasons. EM surveys are used to identify different soil management zones as they are here, but not for irrigation and with little use of the topography data collected at the same time. EM was used for variable intensity of cultivating, and a lot for variable rate seeding. The EM zones are identified and then the soils classified into percentage establishment zones, so then according to your thousand grain seed weight and total population your seed required was automatically adjusted. This combined with using the EM to highlight areas of potentially higher blackgrass burdens - they find much higher levels on heavy soils identified from the EM maps, so they drill at higher seed rates   areas to compete with the blackgrass more. Using variable rate seeding and cultivations the farmers where going far more even looking crops, suppressing the blackgrass marginally more and getting up to 8% increase in yield.

Image 1: Winter wheat VR seed rate from an EM map. 

The EM maps where being used in combination with combine harvester yield maps to create zones for zonal soil sampling rather than grid soil sampling. The advantage there was that you had less samples than grid sampling, so it was cheaper, and you took samples in transects from within each soil zone from the EM map. Most of these farms have no livestock and the fields have been the same size under the same management for a good length of time, which lends itself more to zonal soil sampling.

There was a greater spread use of variable nitrogen from either satellite imagery, drones, N sensor/GreenSeeker type sensors than in New Zealand. The farmers had to use their nitrogen smarter as they had strict limits and timing limitations. This was apparent at the Cereals event on the Yara and Horsch stands to name but two both showing their own real-time sensors.

Image 2: N sensor for real-time VR nitrogen application

Image 3: The Horsch biomass sensor, also for VR N

At Cereals every machinery company seemed to be developing or had its own self propelled sprayer option, from the very basic offering to the other end of the spectrum the Horsch sprayer with its incredible boom technology on the pro plus and nozzle setup, allowing it to follow the crop at a height of just 30cm even on contoured land and almost making it wind proof spraying – with a climate like the UK one, you need to be able to spray at every opportunity you can!

Image 4: The soil pit - a great way to compare root structure in different scenarios

Image 5: There are many different software options in the UK for field inputs and collecting layers of data for smarter farming

It was great to catch up with Jim Wilson and the team from Soil Essentials, one of the few Precision Ag companies who still had a stand at the Cereals Event. The consensus on the Precision Ag front was that there are a lot of interesting and innovative ideas in the pipeline, for growers to use, which is very exciting. 

Image 6: The Soil Essentials team

 All the companies seem to have started from various positions within precision ag but come to the same conclusions on what works best, all of which we are doing here too in New Zealand. Of all the cropping farms there is probably about a 50% uptake in Precision Ag in various forms. Most farms seem to use muck in some form or another to increase organic matter and help with moisture constraints.

The last farm we went to in the UK, was the Beeswax Dyson Farming, owned by the Dyson Company. They had bought over 15,000ha since 2011 and used EM surveys and drones to help them get up to speed on their various soil types to manage them better. They were also heavily involved in environmental schemes like some of the old traditional estates we saw.

Figure 7: Beeswax Dyson Farming, general storage shed

In the next article I will discuss some of the interesting ideas that we came across in Europe. 

Cheers, 

Chris 

EM Surveying - other uses for the data

Today it's our final blog for the 4-part series on EM Surveying that we've run you through over the last month. To date we've covered off:

• Part 1 - the process
• Part 2 - what the data is telling you
• Part 3 - the main uses

Today Chris is going to take you on a run-through of what some of the other uses are for your EM Survey data are & how they can be applied on farm...

...I touched on probe placement at the end of the last post, so will continue where I left off. The EM layers are very useful for making sure you have your moisture probe in the most indicative soil type if you only put one probe in under a pivot for example, or if you have several soil types it ensures you can put probes under the lightest, heaviest and average soils, to make more informed management decisions on irrigation application. The topography information collected at the time of survey can also be used for determining soil moisture probe locations. 

Figure 1: Shallow EM Map with 3 probe locations in the different soil types. 

Where the land is undulating we can bring the elevation data into the equation for probe placement to find a flat area in each of the different soil types. We can also use a moisture probe in a dry land situation for adjusting inputs to the season (such as fertiliser, re-grassing & de-stocking).

When conduiting the EM survey we are using RTK GPS to log the EM data, this topography data and its derivatives are very powerful information layers. We can create water flow maps so you can see potential areas there may be issues for your Farm Environment plans, contour maps, and water flow animated videos as shown below. The Water Shed model mimics a large rainfall event, then over time shows where the water moves from quickly and where it hangs around longer. 

These Water Shed models highlight potential avoidance areas for planting, especially for nurseries and high value crops, in areas prone to heavy rainfall.

As you can see there are many ways people are using their EM survey data, and there are many other uses tailored to the individual client’s requirements. It is generally best to discuss with you your issues then we can work together on using the data to achieve the best solutions for you.

For any more information or to discuss your requirements give me a call.

Chris Smith

Operations Manager @ Agri Optics NZ Ltd 

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 - 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: JEMMA MULVIHILL

Firstly, I’d like to say a big hello to all our blog followers reading this - I sincerely hope you’re enjoying the H2Grow blog that we’re putting together to help you gain more understanding about irrigation and ways in which you can increase the efficiency of not only the irrigation on your property but your farming system in general. But enough about that; let me introduce myself and my motivation for bringing the H2Grow blog to life…

I was born and bred on an arable farm in Mid Canterbury. Like Sarah Elliot I have very fond memories of growing up on the farm and following my Dad and Poppa around on the farm from a very young age. I had pet lambs, and calves, rode ponies, helped feed out, shifted break fences, drove tractors and as I got older, shifted gun irrigators. Because of my love for farming and everything outdoors after I finished high school I went to Lincoln University to study a Bachelor of Agricultural Science. I loved my time at Lincoln, however was getting itchy feet as lots of my friends were travelling so in the third year of my four year degree I decided to get my own travel fix while still continuing my studies by undertaking a year of ‘Study Abroad’ at Colorado State University in the USA. I had an absolute blast and got to take specialist papers on things such as irrigation and Precision Agriculture that we couldn’t do here in NZ which made me think how we could adopt some of the cool things they were doing on farms in the USA back here in NZ. So, I came back to NZ, completed my degree and fresh out of Uni and a bit green, started New Zealand’s first specialist Precision Ag company Agri Optics New Zealand in conjunction with my parents. Over the years we’ve grown the company both in terms of size and also the range of products and services that we offer. We’re now up to a staff of four people and we offer our products and services across the whole of New Zealand.

Discussing the benefits of precision agriculture technologies and practices at a North Otago field day following some very successful trials on the property

While I’m not as hands-on on the cropping farm that I used to be in my younger days, I still keep my hands in the mix with helping with Precison Ag decision making. I also have moved (slightly) further south to Geraldine, South Canterbury where my husband’s family have a sheep & beef farm. The two types of farming are completely different and both offer their unique challenges and advantages. I feel privileged to be involved with both & hopefully with increases in efficiency and the use of technology will be able to take these farms forward sustainably and allow our daughter the upbringing on the farm that my husband and I both have such fond memories of.

Hard at work dosing ewes and lambs on our lease block with Paige learning the ropes

It’s been a great journey so far and I’m sure the future will be just as exciting!

Jemma Mulvihill

Introducing: NICOLE MESMAN

Today's contributor profile introduces Nicole Mesman. Nicole's energy is inspiring. Her intellect and fortitude to challenge the conventional are just two of many reasons that we hope she does not spread her wings too far astray in the future, as agriculture is sure to benefit from retaining talent of her calibre.

NICOLE MESMAN

I am a born and bred Cantabrian, from Christchurch, however I am continuing to spread my wings and experience the rural Mid-Canterbury. My childhood was filled with tramping, skiing and hunting holidays and from a young teenager I would say that I wanted to work with and in the environment and outdoors. Aside from rabbit shooting and hunting I never really did a lot on farms growing up. Lincoln drew me in at the end of high school, not for agriculture though but for biogeoscience (which I would realise was a fancy name for soil science). 

Once I got to Lincoln though my perspective and direction started to change. It’s hard not to get roped into agriculture when at Lincoln. Especially when your friends are doing projects like putting nappies on cows, monitoring cows grazing throughout the night and separating different swards of grass from endless piles of clippings. They were always looking for helpers, the fun we had!

It was a third year soils paper that introduced me to precision ag. We were out digging holes at Craige Mackenzie’s to create a soil map and also determine if the properties of the soils we found agreed with his EM map (the relationship was a good one I will add). After this I spent my summer making cakes out of soil, sand and water to review soil moisture sensors and then continued with my honours which analysed the effect of grazing and irrigation on soil physical properties. 

After Lincoln I worked for Lindsay as a summer student looking at their irrigation systems and EM mapping on various farms before going on to work for Ballance Agri-Nutrients. I am constantly learning more about agriculture and farming and I love it. Whenever I can find out about someone’s operation, learn from them and likewise share what I have learnt with them is a very good day.

Nicole fills up most of her weekends with outdoor pursuits; tramping, skiing, hunting and learning the ropes of day-to-day farm jobs

Nicole Mesman

PAANZ Workshops - Technology to Reduce N Leaching

If you are a farmer or involved in the primary sector and wanting to further understand the issues around N leaching and the potential solutions available to better manage nutrients on farms then the "Technology to Reduce N Leaching" workshop may be of interest to you.

These workshops are being run by Precision Agriculture Association NZ in the North Island on the following dates:

1st September - Palmerston North
2nd September - Hastings 

For more information visit precisionagriculture.org.nz

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!!

An Eye for Innovation at Fieldays 2016

Field days are a great part of working as a rural professional as they are a chance to catch-up with farmers off-farm where the most pressing time constraint for the day is no more than ensuring that you get to the coffee cart before the mid-morning rush and the bargain bin before it empties.

The teams at Agri Optics and Lindsay NZ passion for precision agriculture is innate as is our genuine interest in all things innovative so it is an opportunity to take a look at exciting new products and technologies. We’ve picked out a few of our favourites from the 2016 NZ National Agricultural Fieldays.

Optical Nitrate Sensor

Lincoln Agritech is in the process of developing a low cost, high performance groundwater nitrate sensor. Should this reach commercialisation we think there will be benefits for everyone who enjoys our rivers and lakes.

Jens Rekker was showing off the nitrate sensor prototype at #fieldays2016

Agriculture’s contribution to nitrogen concentrations in freshwater bodies has been under the microscope for several years now. Part of New Zealand’s approach to allow for continued primary sector growth whilst managing environmental impacts is the establishment of nitrate caps on farming operations. However a major challenge for those involved in these negotiations is the limitations of the current modelling to define the net effects on rural water quality.

It is this ambiguity that a direct, real time sensor with high spatial accuracy will resolve, closing the loop on the science so to speak. And therefore could be a vital tool to validate sustainable resource use and manage environmental impacts. We will be watching this space with great interest.

Pasture Robot

The pasture sensing robot is being developed as a joint project between Massey’s Centre for Precision Agriculture and the School of Engineering and Advanced Technology and aims to help farmers generate better information about the pasture and soils on their farms.

Pasture sensing robot on display at #fieldays2016

The current prototype has a multi spectral camera mounted which allows you to map nutrient variability. Plans are to enable the robot to be equipped with different types of sensors which could measure a number of soil or crop parameters. The development team envisage having it pre-programmed to be able to leave its docking station at say 4am to run a predefined pattern using RTK GPS and automatically send back the information to the office. This could be pasture growth levels, nutrient levels, moisture content, basically data from whatever sensors you have it loaded with. Unfortunately, it won't get your cows in for you........yet!

Current sensing technology is typically carried on planes or drones and uses expensive and complex equipment. A robot is a cheaper option that would also be more reliable as it is less weather dependent than drones. The hope is the robot will be fully automated, reducing time spent by farmers assessing pasture quality.

CalfSMART

CalfSMART shows new thinking in automated calf rearing.  The system delivers the right balance of nutrition to each and every calf. Calves are identified by their RFID ear tags. CalfSMART sends information on all parameters to your smartphone or computer.

Karl Watson demonstrates the latest CalfSMART automated calf feeding system.

This new product leverages on two technology platforms that have enabled the development of many instrumental agricultural products; RFID animal identification and the smartphone. The power of the smartphone as a farming tool is massive, so many exciting apps have been developed in recent years giving farmers unparalleled access to control and data!  

FarmWalker

FarmWalker (from FeedFlo) is a wireless data capture solution for rising plate meters. It allows easy data capture utilising a smartphone app. The app uses the phones GPS to log spatial data as well as pasture mass data. In essence the FarmWalker can build a low resolution pasture yield map, eliminating the requirement for any manual data handling and processing. This app could be a handy addition to a pastoral farmers’ toolbox enabling easy, basic yield mapping.

Robot Ron from Bosch

Robot Ron’s potential could be endless, perhaps his eyes are multispectral cameras, perhaps his feet are DualEM sensors, perhaps he will trim your front hedge after mowing your lawn… we’re not quite sure but he was a hit with every 10-year-old visiting the fieldays this year.

And finally the latest in Farmall tractor ergonomics, shown off during a parade of tractors around the Fieldays.

So thanks to the farmers, the families, other exhibitors, the coffee cart girls and guys, and all those that popped in to say hello and made our week at Mystery Creek so enjoyable!

This post is a combined effort by Nick, Chris, Paul, Stu and Sarah.