Grower Andrew Scanlon of Quailerup Nominees, Wagin, participated in the CSBP Detect pilot program in 2021.
He was interested in the pilot to get a sense check on his crop nutrition management and whether there was any potential for improvement. As part of the pilot, Andrew chose two barley paddocks sown with Planet; “Shed” and “999 East”, to sample throughout the season.
The CSBP Detect pilot involved in-season sampling that included both Detect scans for nitrogen (N) content and whole top plant sampling through the CSBP Soil and Plant Laboratory of the same plant material. At the end of the season crop heads were collected from the same locations to assess yield and water use efficiency, as well as to measure nutrient content and nutrient removal via the grain.
Andrew asked his local CSBP Account Manager to take additional Detect scans on other paddocks during the season and found that monitoring the N status of the crop helped with decision making.
The final part of the CSBP Detect pilot was to review the sampling information generated over the course of the season with Andrew. The discussions between Andrew, the CSBP Detect team and the CSBP agronomy team were critical in helping Andrew diagnose the likely reasons behind the disappointing yields from these paddocks and a course of action to minimise this in future.
Based on the rainfall during the season and his own experiences in farming the area, Andrew had expected yields to be around 5 t/ha. Come harvest, paddock 999 East had an average yield of 3.9 t/ha, and the Shed paddock had an average of 4.3 t/ha. Andrew stated that head loss had occurred just before harvest and assessed this at about 10%. This still did not account for the relatively poor yield, particularly for 999 East paddock. Andrew had split his nitrogen applications with:
- 60 L/ha of Flexi-N with a blend of 90 kg/ha AgFlow and 40 kg/ha Muriate of Potash (MoP) banded at seeding.
- 100 kg/ha urea and 40 kg/ha of MoP blend at tillering.
- 60 L/ha Flexi-N top up at stem elongation.
With a total of 83 kg N/ha on each paddock and reasonable organic carbon levels of about 1.4%, this should have been enough N to grow about 4 t/ha of barley at 10.5% protein.
In reviewing the plant sample results during the season, the plant levels for copper (Cu) in 999 East paddock indicated adequate levels at the start of the season. Samples at later growth stages showed two sites dropped to a marginal status at around 2 mg/kg and one site at deficient levels of 0.45 mg/kg. The grain samples for two of these sites showed Cu levels of 1.1 to 1.3 mg/kg, with the protein at 8.1%. Two other sites on this paddock had protein as low as 7.4%, which indicates N was limiting. Due to the head loss, yield assessments were compromised and were not able to be used.
While there were no grain samples taken from the Shed paddock, the plant sample result showed the opposite of the 999 East paddock. Mid-tillering plant samples in the Shed paddock had marginal to low Cu levels of 2.7, 1.5 and 2.8 mg/kg, but for the later growth stages, the plant test results increased to 8.2 – 21 mg/kg.
Once Andrew was presented with these results, he checked his paddock records and found that he had not applied the usual 250 mL/ha of foliar Cu oxide in the 999 East paddock. This application was planned but delayed due to waterlogged
conditions, where the delay meant combining a number of different chemicals in one pass. At this point the copper spray was dropped due to concerns about crop effects. This chemical mix is still suspected of causing root damage to the crops, which would have led to reduced uptake of nutrients, including Cu and N. The Shed paddock had received this Cu spray earlier with the other chemicals, split across two applications. The impact of this Cu spray was evident with the jump up in levels in the plant test for later growth stages.
Andrew estimated that for the relatively small cost of a foliar application of $4.50/ha, this resulted in yield losses of at least 400 kg/ha across the paddock. At a barley price of $280/tonne, this meant a loss of $110/ha across the 228 ha paddock, which sums to a total loss of $25,000. This work highlighted to Andrew the need for Cu applications and to get it out onto paddocks at the earliest possible opportunity. It also highlighted the benefits of monitoring nutrition levels to help diagnose limitations to crop production and addressing these limitations early so the crop response to subsequent N applications is more likely to be profitable.
After a successful pilot in the 2021 season, CSBP Detect can now be accessed by growers alongside CSBP’s existing soil and plant analysis.
If you are interested in understanding how CSBP Detect or soil and plant analysis can help with your fertiliser needs, please reach out to your local CSBP account manager or find out more here: csbp-fertilisers.com.au/detect