The irrigation season is just around the corner…

With the days getting longer and the weather getting warmer (I’m sure it’s too good to be true!) spring growth will soon be kicking into gear and irrigation season will be just around the corner. Now is the time to be ensuring that you’re as prepared as you can be for the irrigation season.

If you’re an irrigated farmer now is the time to be thinking about how you’re going to schedule your irrigation throughout the upcoming season. The days of scuffing the dirt with your boot and having a dig with a spade are fast coming to their end with the need for on-farm soil moisture monitors such as the AquaCheck probe, to give some more accurate numbers to the soil moisture levels than a scuff of your boot on the soil. Having soil moisture probes installed on farm not only helps you make better irrigation decisions but it also gives you some hard and fast data to have when it comes to Farm Environment Plan (or the likes) auditing.

Soil moisture probes for use this coming season should be being installed now or over the next few weeks ideally. All continuous soil moisture measurement devices take a period of a few weeks to ‘settle down’ and give accurate readings post installation.

At Agri Optics we have a great soil moisture probe in the AquaCheck probe as part of our suite.

The key things to note on these probes compared others (other than their great price) are as follows:

·         They’re fully telemetered, giving you access to view up-to-date soil moisture data and make timely decisions based on current, actual data

·         They’re a vertical oriented probe that has multiple soil moisture sensors down their length, giving you a total soil moisture trace and soil moisture traces at each different sensor depth. This means that you can see how the soil moisture moves down through the soil profile and how effective you’re being with your irrigation management. The bottom sensor is also a good ‘check’ for drainage leaving the root zone

·         The AquaCheck probe has built-in soil temperature sensors – a good gauge to be able to better manage irrigation and fertiliser timings in the shoulders of the season in particular

·         They have the option of connecting to rain gauges to give accurate records of rainfall and irrigation at each soil moisture probe site

·         They have a short ‘settling’ time post install compared to most of their competitors, meaning that you’ll get useful data to make decisions off in a short time frame

·         They’re easy to install and uninstall, making them great for seasonal cropping situations

·         They’re very competitively priced

·         There are multiple depth option so that the depth of the probe installed can be matched to your farming system and requirements

·         In NZ they’ve got Agri Optics behind them, to help you, the farmer understand and interpret soil moisture readings and get the most out of soil moisture probes for irrigation scheduling

You can also view more information on the AquaCheck probes on our website: http://www.agrioptics.co.nz/portfolio/aquacheck/

If you’re interested in the AquaCheck probes or need a soil moisture solution for this season please don’t hesitate to contact one of the Agri Optics Team for some more information and a quote.  

All the best for an upcoming irrigation season & year ahead!

Cheers,

Jemma

Improving Irrigation Efficiency for Only $50

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

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

Considering Root Depth when Measuring your Soil Moisture Levels

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

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

Winter Is Coming! Tips for preparing AquaCheck soil moisture sensors for winter.

Preparation for winter is key when soil moisture is involved. Once soil moisture probes have been removed from the paddock the first thing to do is plan where they will be installed for the coming season. Choice of paddock, crop and location are all important.

 Re-installing the probe in a similar location for the following season will allow for the comparison of moisture management from year to year. It can also provide insights into how soil moisture is used by different crops in a rotation. Re-installing the probe in a different paddock will require some thought as to where the probe should be placed. Ideally a few key things should be considered as to the location:

Plan:

• Choosing a location that is representative of the paddock. If an EM survey has been done then a location can be selected from the results. If no EM survey has been conducted then a location that looks, or has anecdotally been, representative of the paddock should be identified.
• Make sure that the site is located in the middle third of a pivot, isn’t under any towers or under the end gun and that nozzles that pass over the probe aren’t blocked. Generally placing the probe in the middle of a span is optimal.

Prepare:

• Run the pivot or lateral over the paddock if possible so that wheel tracks are easily identifiable.
• Ensure that tramlines can be identified. This is to avoid installing too close to the tramline. 
• Generally installing after the first spray or fertiliser application is ideal.
• Winter provides the best time for soil moisture probes to bed in. Therefore it is important that probes are installed as early as possible. By installing early it allows for the soil profile to have time to rebuild structure around the probe which is key for accurate data capture. On top of this winter time will provide an opportunity to identify the soil moisture field capacity.

A recent install ready for winter. Tramlines are visible in the background.

If the probes are not being re-installed prior to winter then the following will apply:

• Disconnect the probe from the AquaLINK 3G telemetry unit. Store the probe in a safe place. Particularly away from anything that may chew on the cable.
• Place the AquaLINK 3G telemetry unit on a windowsill or in the garden, somewhere it will receive sunlight. This is to ensure that the battery remains charged up over the winter.
• If the probe is not going to be used for a whole calendar month contact Agri Optics to get the connection deactivated and save on the monthly bill.

Remember the 6 Ps. Prior Preparation Prevents Piss-Poor Performance. Ultimately your soil moisture management will be improved due to accurate and timely data from probes that are installed in the right place and as early as possible.

Inaugural PAANZ Conference - Summary

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

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

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

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

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

Some Key Principles for mitigating N leaching

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

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

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

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

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

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

~ Jemma

The EM Surveying Calendar

We have had another successful EM year so far and our clients have used their surveys for many different uses. I will go into that in more detail in a future blog. Today I will cover the EM and the four seasons. I often get asked when the best time to conduct a survey is, the answer is any time from late autumn through winter into the spring right up to late November.

For an autumn survey, natural moisture is our deciding factor on start dates.  Once the irrigation on farm has finished and we have had at least a good 50mm of rain to balance out any irrigation affects, we can start EM surveying. This year we held off until the end of April and in some areas south of Oamaru and north of Canterbury later still, as we didn’t get the 50mm+ for quite a while. So we concentrated on the areas that once they got too wet we knew we would not be able to get on again! Getting this sort of information from our client’s knowledge of the land is very useful to help with the logistics and completing the survey with as little fuss as possible. Once on site we are self-sufficient and conduct the survey without the client having to get involved, but we rely on good information on the conditions to manage the logistics before we arrive!

Getting ready to start a survey in Ellesmere, early May.

Winter is ideal for surveying and the concerns here are not getting stuck and being able to get along without making a mess especially in cropping situations. We can juggle between all grassland projects and cropping regimes as the weather fluctuates between torrential rain and drying enough so we can travel on it! It involves shifting jobs around depending on the conditions to ensure we get all the projects conducted in a timely manner, not making a mess or damaging crops and without too much to-ing and fro-ing, to ensure all data is collected as efficiently as possible. On some farms we have to leave a few paddocks if they have winter feed crops in or crops in the ground still to be harvested, in that situation we can come back in the spring and drive some transects over the rest of the project and tie all the data in together. Ponded surface water is not an issue and does not interfere with the EM readings and results. If there is a big rain event between starting and finishing a project we can tie the data together be driving transects and using our robust protocols to ensure data quality is not compromised. The only weather that stops us is snow! Mainly because we can’t see the ground and any potential hazards are covered up, as well as getting to and from the site can be tricky, we had a few close calls getting in and out of regions this winter but we managed to keep ahead of the snow!

Surveying near Staveley in July once the snow had thawed.

In the spring we also get good results, the temperature is a little warmer and we can get along very well in most cases, the only issue comes in the cropping situation when the crops start to get too tall. Generally we are fine in a cereal crop until stem elongation. Again it is a matter of logistics and knowing the clients requirements, timing limitations and concerns, as long as there is good communication this is not an issue. We can and have EM surveyed right through to early December before in dryland situations where there has not been any irrigation and good natural moisture. Once clients start irrigating the influence of the irrigation pattern will start to show through in the data. In the summer itself the ground is too dry, the variation in your soil textures is still there but the low moisture levels means the range in EM units is reduced and the EM profile compressed so outside influences start to creep in and have more of an effect on the readings so reducing the quality of data – which is the main reason we make a conscious decision to stop as quality data is of paramount importance. In situations where we are just looking to gauge salinity issues then we can go later as the very high EM values (150-600 mS/m) are not affected by moisture, but for general EM work we stop and concentrate on the other areas of precision agriculture until the following autumn. 

Surveying in late August on a freshly drilled spring barley paddock near Blenheim.

Now we are getting to the end of August if you are still interested in getting a survey conducted this year please let us know as soon as possible otherwise you may have to wait until next autumn.

Chris Smith

Field Manager Agri Optics NZ Ltd

Temperature – How cold is too cold?

Following on the theme of soil (moisture) sensors, this blog is concentrating on soil temperature.  At this time of the year (mid-August) soil temperature is or has become the most important factor influencing irrigation (and to a lesser degree fertiliser application).  Just like soil moisture, if you don’t get the installation or measurement point this right you will never get any decent data and never be able to utilise the soil temperature measurements with any confidence.  There are three key requirements for soil temperature measurement:

a)     Ensure any sensor is centred at 10cm depth or the measurement is taken at 10cm;

b)     Ensure the sensor or measurement taken is under the crop/pasture (not in a bare patch for example); and

c)     Temperature is measured at 9am (and not 9am daylight saving time).

Why is 10cm depth and 9am so important?  Crop production models use the 9am 10cm soil temperature as a key input parameter.  If the soil temperature is not above the base temperature at 9am then production will be affected.

It is imperative you measure soil temperature on your farm and in the paddocks of interest.  As at mid-August there is a wide range in soil temperature.  On the east coast of both islands the temperature gradient is large – warm enough for pasture growth in the North Island and too cold in the South Island.

In the northern east coast of the North Island (Gisborne area) temperatures have already peaked above the base temperature for pasture at 15°C and have been above 10°C for 6 days in August.

In the South Island (in the example mid Canterbury) temperatures have not even approached the 10°C base temperature.

So whether you have soil moisture sensors installed that also measure soil temperature or you use a $50 manual gauge, measure soil temperature from now to assist and guide the need to irrigate.

For more information on anything in this blog please contact HydroServices