In a drive for efficiencies we are seeing intensive double cropping forage rotations that use the same species in the same paddocks year-in and year-out.
This makes sense when chasing high volumes of quality feed, but doesn’t come without some risks.
Experience from the grains industry shows these types of simple rotations can lead to issues around weeds, pest and disease and soil health impacts which can, over time, lead to production penalties.
As part of the C4 Milk program — a three-year partnership between Murray Dairy, Dairy Australia, the Gardiner Foundation and the Queensland Department of Agriculture and Fisheries — we will be looking at the crop-on-crop effects (quality, yield, agronomic and environmental) of common rotations in intensive fodder systems.
With any farming system, single year production only tells a very small part of the story.
By understanding the cumulative effect over multiple years of intensive cropping we can determine the agronomic and economic impact of systems and understand what stacks up year after year.
How important are break crops in these systems to ensure the whole farm is productive all the time?
The focus of this project is on intensive cropping feedbase systems, but the implications will be of note to the full gamut of dairy systems in the Murray region.
Murray Dairy is heading up the C4 Milk project.
It was developed out of the outcomes of previous Murray Dairy projects that have tracked changes to inland dairy farm systems and the increased utilisation of grain crops for fodder.
These include the Accelerating Change project (2018) and the Fodder for the Future project (2023).
Summer and winter grain crops are increasingly of high value in the region due to their ability to grow a bulk of quality feed to either directly graze or conserve for future feed gaps, and their increased water use efficiency.
Experiments are being carried out by two field research organisations at two locations in northern Victoria — a dryland site near Mitiamo by the Birchip Cropping Group (BCG) and an irrigated site near Kerang by the Irrigation Farmers Network (IFN).
They are testing the impacts of break crop strategies (for example, single or double) and the types of crops used.
The break crop strategies are implemented over the first three seasons — winter 2024, summer 2024 and winter 2025 — with the second winter hosting the main break crop type treatments.
The impacts of both the strategies and the crop types are then tested over the following seasons (summer 2025 onwards).
Treatments will be replicated four times.
By working directly with BCG and IFN, the project will have access to local trial sites as well as the latest up-to-date information and experience relating to crop rotations from the grains industry.
The aim of the double break crop treatments is to boost potential effects on subsequent crops and improve our ability of seeing effects over a short timeframe.
This is being achieved in two ways — consecutive winter break crops (2024 and 2025) at both sites, and consecutive season break crops (summer 2024 and winter 2025) at the irrigated site.
DRYLAND SITE
The dryland site (Birchip Cropping Group) can grow one crop per year over winter and is fallow over summer due to lack of rainfall.
It will have eight treatments — two break crop strategies of four break crop types.
The break crop strategies are single and double. The break crop types are barley (control), vetch, canola and oats.
The crop sequences for each of the eight treatments over the multiple years are shown in the top table.
IRRIGATED SITE
The irrigated site (Irrigation Farmers Network) can double crop (grow summer and winter crops) and will have nine treatments (three break crop strategies of three break crop crop types).
The break crop strategies are single, double (winter-winter) and double (summer-winter). The break crop types are wheat (control), vetch and canola.
The crop sequences for each of the nine treatments over the multiple years are shown in the bottom table.
Outcomes from this project will be shared with dairy farmers and fodder producers through a number of field days, crop walks and information resources.
For more information, contact Murray Dairy research and innovation coordinator Yvette Williams at: yvettew@murraydairy.com.au
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