Riskwi$e: To Fallow or Not to Fallow? Soil Moisture Management and Cover Crop Risks and Rewards

2025

Research organisation

Funding source

<abbr title='Grains Research and Development Corporation'>GRDC</abbr>

Trial details

Researcher(s)	Chris O'Callaghan Aeneva Poulish
Contact email	admin@liebegroup.org.au
Year(s)	2025
Contributor	Liebe Group
Trial location(s)	Pithara, WA

Riskwi$e: To Fallow or Not to Fallow? Soil Moisture Management and Cover Crop Risks and Rewards locations

Aims

This trial aims to explore key uncertainties in crop sequencing and nitrogen management, offering growers practical insights to support better decisions and reduce on-farm risks. It forms part of the national GRDC RiskWi$e project, which works with Australian grain growers to evaluate farm management strategies that balance risk and reward.

Key messages

Significant response to nitrogen when there was no legume or fallow in the rotation.
Legume and fallow phases provided sufficient nitrogen in 2025.
The yield benefit of fallow was not enough to justify leaving the crop out at this site in 2024.

Lead research organisation	N/A
Host research organisation	N/A
Trial funding source	GRDC GGA ARG001-NRMI-RTX
Related program	N/A
Acknowledgments	This trial is part of the National Risk Mitigation Initiative which is a GRDC investment, led by CSIRO. Project Code GGA ARG001-NRMI-RTX. The Western Australian component is led by the Grower Group Alliance. The Liebe Group acknowledges Living Farm for managing the trial throughout the year. Thank you to Brad McIlroy for hosting the trial.
Other trial partners	Not specified

Download the trial report to view additional trial information

Method

Crop types	Grain Legume: Lupins Cereal (Grain): Wheat
Treatment type(s)	Crop : Rotation Fallow : Chemical Fallow Fertiliser : Rate
Trial type	Unknown
Trial design	Replicated

Pithara 2025 Lupins

Sow rate or Target density	100 kg/ha
Sow date	28 May 2025
Harvest date	4 December 2025
Plot size	8.75m x 8.1m
Plot replication	3
Fertiliser	Pre: 110 kg/ha MacroPro Extra with Impact
Herbicide	28/05/2-25: 3 L/ha Weedmaster DST, 1 L/ha Treflan, 1 L/ha Rustler, 1 kg/ha Simazine, 3 L/ha Sprayseed
Insecticide	Not specified

Pithara 2025 Wheat

Sow rate or Target density	70 kg/ha
Sow date	28 May 2025
Harvest date	4 December 2025
Plot size	8.75m x 8.1m
Plot replication	3
Fertiliser	110 kg/ha MacroPro Extra with Uniform ; 100 kg/ha Urea
Herbicide	28/05/2025: 3 L/ha Weedmaster DST; 1.8 L/ha Treflan; 1.8 g/ha Sakura; 200 mL/ha Voraxor
Insecticide	28/05/2025: 800 mL/ha Chlorpyrifos; 100 mL/ha Bifenthrin

Download the trial report to view additional method/treatment information

Trial source data and summary not available
Check the trial report PDF for trial results.

Observed trial site soil information

Trial site soil testing

Not specified

Soil conditions

Trial site	Soil texture
Pithara, WA	Not specified

Derived trial site soil information

Australian Soil Classification Source: ASRIS

Trial site	Soil order
Pithara, WA	Kandosol

Climate

Derived climate information

No observed climate data available for this trial.
Derived climate data is determined from trial site location and national weather sources.

Pithara WA

SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.

Trial report and links