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