1. Potassium for wheat on sandplain soils
West Midlands Group
March 2017

2. Potassium
Source: Fertilizer Australia

3. Potassium
Source: Fertilizer Australia

4. Potassium – Moora/Midlands

5. Potassium – Moora/Midlands
Total samples: Samples <50 mg/kg: % % % %

6. Potassium - Moora Glen Ruff, 2017 Questions:
Depth
NO3-
NH4+ OC P
PBI K S Cu Zn
pH[Ca]
Al[Ca]
0-10cm 16 4
0.69 18 24 7
0.39
0.78
4.7
1.5
10-20cm 8 3
0.42 22 26 5
0.40
0.31
4.5
4.9
20-30cm 2
0.20 29 15
0.26
4.4
7.1
30-50cm
0.00 12
5.3
Questions:
What does the K response look like?
K in each granule with N+P+traces, enough?
or boosted with extra MOP applied as blend, PSPE and 4WAS, what works best?

7. Potassium - Moora Glen Ruff, 2017 Mace wheat, 14 May
12 x treatments, Replicates x 3
Basal: P 16, S 15, N 90 kg/ha split
K rates: K 0, 12, 17, 30, 42, 55 kg/ha
K source: NPK granule +/- additional MOP
Timing and method: drilled at seeding, drilled + MOP topdress PSPE, drilled + MOP topdress post emergence [4WAS]

8. Potassium - Moora Yield: Treatment differences significant.
Up to 500 kg/ha response to K.

9. Potassium - Moora
Yield curve and returns

10. Potassium - Moora
Good quality. Vigour kg/ha not quite enough K.
Trt K
Source
Fert# $/ha
Yield t/ha
LSD p<0.05
Protein %
Hecto litre
Scrngs %
Grade
Grain* $/ha
Returns $/ha 1 0K -
$142
2.54 a
10.5
80.4
1.2
APW2
$613
$471 2 13
Vigour
$159
2.77 b
80.6
1.0
APW1
$680
$521 3 17
$176
2.83 bc
10.4
80.8
1.1
$682
$506 4 30
Vigour+MOP band
$193
2.88
bcd
$695
$502 5
Vigour + MOP PSPE
2.95 cd
$723
$530 6
Vigour + MOP 4WAS
2.93
$706
$513 7 42
$210
10.3
80.5
$710
$500 8
2.92
$704
$494 9
2.96
80.2
$726
$516 10 55
$227
10.6
80.9
$715
$489 11
2.82
$681
$454 12
3.03 d
1.3
$730
$503

11. Potassium on sandplain
Vigour, 100 or 140 kg/ha not enough K (12 – 16), especially for a strong year
Recommend K rate 30 kg/ha on soil approaching lower limits of test accuracy
As an NPK compound granule with 12% K this is equates to 250 kg/ha of product – also giving P 30 kg/ha
Compound + additional MOP is a preferred strategy
No clear standout of timing or placement for the additional MOP – however trials in less favourable rainfall years show better efficiency from banded K

12. Potassium Merredin Colwell K = 132 mg/kg
Ballidu 2015 Colwell K = 37 mg/kg
Baandee Colwell K = 25 mg/kg

13. Thanks - Michael Brennan
- Living Farm

14. In-season N decisions for wheat

15. Nitrogen, N Gauges and N Calc
L/ha UAN strip
kg/ha above surrounding paddock – a “luxury” amount

16. Nitrogen, N Gauges and N Calc

17. Nitrogen – Moora Mace wheat sown 14th May Tmt N
Seeding Fertiliser product kg or L/ha
PSPE
L/ha
4WAS
Kg/ha A
SSP 90, TSP 20, MOP 25
MOP 25 B 30
Vigour 100, MAXamFLO 70 C 50
UAN 50 D 90
UAN 150 E*
120
UAN 220

18. Nitrogen – Binnu
NDVI readings 27 July [74 DAS] to In-Season N Calculator

19. Nitrogen – Moora Mace wheat sown 14th May Tmt N
Seeding Fertiliser product kg or L/ha
PSPE
L/ha
4WAS
Kg/ha
NDVI input into N Calculator for N rate recommendation
27/07/16 A
SSP 90, TSP 20, MOP 25
MOP 25 B 30
Vigour 100, MAXamFLO 70
0.264# C 50
UAN 50 D 90
UAN 150 E*
120
UAN 220
0.410
Tmt
Seeding N
Seeding Fertiliser product kg or L/ha
4WAS
In-season N rate determined by N Calculator
N kg/ha UAN L/ha 1 30
Vigour 100, MAXamFLO 70
MOP 25
N Calculator x 50%
12.5 2
N Calculator x 100% 25 60 3
N Calculator x 150%
37.5 90

20. Nitrogen – Moora

21. Nitrogen – Fuel Gauges Fuel gauges – 2016, all trials yield and return
Location
Crop
N Calculator recommended rate N kg/ha*
N Calculator Yield prediction
Actual Yield t/ha and [Gross Margin]#
50% N rate
100% N rate
150% N rate
Binnu A
Wheat 23
4.24
3.84 [$752]
4.19 [$809]
4.31 [$817]
Binnu B 19
4.42 [$859]
4.61 [$885]
4.68 [$883]
Moora 25
1.94
2.12 [$315]
2.54 [$420]
2.47 [$412]
Cranbrook A
Barley
3.29 [$547]
3.61 [$592]
3.56 [$564]
Cranbrook B 18
3.34 [$537]
3.67 [$589]
3.78 [$587]
Darkan A 9
3.11 [$438]
3.43 [$500]
3.29 [$483]
Darkan B
12.5
3.15 [$473]
3.07 [$444]
2.92 [$404]
Wandering A
Oats 29
3.45 [$481]
3.71 [$505]
4.08 [$547]
Wandering B 16
3.95 [$553]
4.27 [$597]
4.29 [$588]
Wickepin A 14
4.63 [$569]
5.06 [$620]
5.07 [$611]
Wickepin B 12
4.89 [$609]
5.27 [$655]
5.17 [$631]

22. Nitrogen – NDVI and N Calculator
2016 trials key messages
Data continues to build confidence in recommendations and predictions
Reliable in-season N decisions in wheat
Rates not excess to crop requirement and produce maximum or near maximum returns
Getting mid-season N decisions right can have a significant impact on profitability since optimal top up N rates indicatively increased yields by 480 kg per hectare and net returns by $70 per hectare
Recommend: N at seeding + N-Gauge + N-calculator

23. Thanks - Michael Brennan
- Living Farm

24. Nitrogen, N Gauges and N Calc
Summit In-Season Nitrogen Calculator
Developed by David Cox in Esperance
Based on relationship between mid-season biomass and end yield
Calibrated by a response index from many N response trials
Principle: how the crop plants are growing is a continual, dynamic and real-time indicator of all the factors that determine N status
Therefore, comparing plants in unlimiting and limiting N situation can tell you their potential to respond to N application.

25. Nitrogen, N Gauges and N Calc
NDVI
Normalised Difference Vegetation Index
Living leaves absorb visible red light wavelengths and reflect/re-emit near-infrared wavelengths
NDVI = (NIR − RED) (NIR + RED)
We measure NDVI with tools like the Greenseeker® that compare absorbed versus emitted light
NOTE: NDVI does not measure the amount of N in a plant or what a plant needs – this needs to be modeled and calibrated against controlled rate trials
NIR nm
Red nm

26. Nitrogen, N Gauges and N Calc
Summit In-Season Nitrogen Calculator Assumptions
Decile 5 rainfall for remainder of growing season
Minimal shoot disturbance (pest/disease/physical)
Minimal root growth restrictions
No nutrient limitations other than N
Target grain protein 10.5% (wheat, barley)
We want to use live trials to demonstrate how it works, test the predictions and usefulness for growers