As part of the GRDC More Profit from Crop Nutrition (MPCN) initiative, multiple workshops and events have been held across the southern region. Participants from these events were influenced to make better decisions to improve more profit from their crop nutrition.
With fertiliser accounting for a significant proportion of the farm input budget, the McQueen family, who manage 5800ha in the northern Mallee, have been carefully considering opportunities to make better use of their fertiliser dollars.
In 2014 Brad, who manages the property in partnership with his father Roger, sister Lisa and brother-in-law Simon, attended a workshop focused on spreader calibration and nitrogen and sulphur management in the Mallee.
The workshop, hosted by Natya-Kooloonong Landcare Group and Birchip Cropping Group, and funded by the GRDC through it’s More Profit from Crop Nutrition (MPCN) initiative, featured a presentation from highly regarded Accu-Spread specialist Russell Nichol who performed calibrations on a number of locally owned fertiliser spreaders.
Having recently purchased a Marshall fertiliser spreader, Brad was keen to see how it compared with other spreaders and how correct callibration might improve any limitations.
“Putting fertiliser in the right place isn’t just about where the fertiliser is applied at sowing,”
he said.
“Significant savings can be made by making sure that your in-season fertiliser applications are accurate. “It’s always worthwhile to test things out in a paddock situation and not just rely on the manufacturer’s claims which are made from assumptions in the factory.”
Understanding the quality of fertiliser and how this affects spreading was a key take home message, according to Brad.
Russell said high quality fertiliser should have larger granules, improving its spreadability. However, spreaders can be calibrated according to the size of the granules, improving performance.
The spreader calibration showed that the McQueen’s machine wasn’t spreading as far as they had thought. As a consequence, with good support from their dealer and manufacturer, improvements have since been made.
“With the spreader not quite reaching target, we could easily have been supplying parts of the crop with little to no extra fertiliser, and other parts with too much,” Brad said.
“By making sure we know exactly how far the machine is spreading, we can make sure there is minimal wastage of resources either way.
“Ideally a spreader that can go further will mean fewer passes, but calibrating is important as well … it’s about making sure the money is spent where we plan on it being spent.”
To better understand their crop’s nutritional requirements the McQueen family created some test strips on their farm at seeding, predominantly to verify P levels.
“The phosphorus buffering index (PBI) suggested that we could lower our P rates at the Kooloonong farm,” Brad said.
“There was no effect evidence at harvest (2014) so we reduced our MAP rate back to 25kg in 2015.” Brad said locally relevant workshops, such as the spreader calibration day, gave growers practical tips and knowledge to improve their businesses.
“Hopefully we are spending fewer fertiliser dollars and still getting the returns.”
FARM DETAILS
Case study: McQueen family
Location: Kooloonong and Nyah West
Farming operation: cropping and sheep
Mean annual rainfall: 325mm
Soil type: sandy loams with some-wetting sands
MPCN SPREADER CALIBRATION WORKSHOP
The spreader calibration day at Kooloonong also saw growers visiting BCG trials with a nutrition focus.
In 2014 BCG carried out a nutrition trial on a paddock adjacent to the site where the spreader calibration demonstration was performed. One of the trials visited was investigating the effect on nitrogen (N) and sulphur (S) timing in the Mallee on deep sands (2014 BCG Season Research Results, pp. 159).
The trial results showed that there was no response to S, however, there was about a 0.4t/ha increase when N was applied. There was no critical stage when either the N or S
was needed; the response was the same.
Although the trial was not established on a ‘classical’ deep sand, it was still on a rise where S is typically applied. Both S and N are mobile in the soil, which sometimes means that after a heavy rainfall they can be washed from the immediate root zone.
Responses in these cases can be variable because there may be short-term deficiency symptoms appearing in the crop, however with rapid root growth, the plant will soon access the S and N further down the profile.
In extremely deficient scenarios, growers can often tell which element is required simply by looking at the crop. Although S and N are both mobile in the soil, this is not the case within the plant.
Nitrogen, is mobile in the plant which leads to the older leaves turning yellow. Conversely, S is immobile and the newer leaves will appear yellow.
Understanding this fact can be very important when deciding whether urea or sulphate of ammonia is required. Messages from the Kooloonong trial were clear. Spreading N applications allows growers to better manage risk and adapt fertiliser inputs according to the season.
On the soils at Kooloonong (a sandy loam with no subsoil constraints) it was better to spend money on N applications than S which did not make any return on investment.
This same message has been highlighted by research carried out by Dr Sean Mason (University of Adelaide), where responses to S have been hard to achieve.
Growers are advised to monitor and balance fertiliser inputs with crop removal rates (Table 1).
TIPS FOR TEST STRIPS
- Make sure there is an area/strip with no fertiliser.
- If using a fertiliser mix make sure that N is either balanced or non-limiting to ensure any response is from the nutrient and not N.
- Add two rates, a standard rate on one side, and double the rate on the other side of the nil strip.
ABOUT MPCN
BCG is carrying out extension in the southern region as part of the GRDC More Profit from Crop Nutrition II initiative (MPCN).
The project – Extension and training in the southern region (BWD00021), focuses on empowering growers and advisors with the knowledge, skill and tools required to maximise their return on investment into crop nutrition.
The BCG team pools information from well renowned soil and crop nutrition specialists and from the suite of the MPCN projects to deliver events relevant to growers across the region.
For further information about the project contact BCG on 03 5492 2787.
ADDITIONAL INFORMATION
For further information pertaining to the 2015 season, please use the links below.
