Potassium for wheat on sandplain soils West Midlands Group March 2017

Potassium Source: Fertilizer Australia

Potassium Source: Fertilizer Australia

Potassium – Moora/Midlands

Potassium – Moora/Midlands Total samples: Samples <50 mg/kg: 1655 31% 1619 28% 1504 39% 721 37%

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?

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]

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

Potassium - Moora Yield curve and returns

Potassium - Moora Good quality. Vigour 100-140 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

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

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

Thanks - Michael Brennan - Living Farm

In-season N decisions for wheat

Nitrogen, N Gauges and N Calc 200-240 L/ha UAN strip 85-100 kg/ha above surrounding paddock – a “luxury” amount

Nitrogen, N Gauges and N Calc

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

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

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

Nitrogen – Moora

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]

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

Thanks - Michael Brennan - Living Farm

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.

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 750-1300 nm Red 600-700 nm

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