Summer Crops: Fodder for Thought

By BCG Staff and Contributors

Kate Finger (BCG)

 Take Home Messages

  • A saturated soil profile at the start of the summer sowing window was not enough to support forage crops through the 2021–22 summer due to high temperatures and sporadic follow up rainfall events.
  • Growers in low rainfall environments should not rely on summer storms for establishing summer cover/forage crops — they are too unpredictable.
  • Summer cover/forage crops have a limited a fit within the Victorian Mallee due to reliance on stored soil moisture to support the main farming practice of dryland winter cropping.


The Victorian Mallee in recent years has had several summer forecasts indicating an increased chance of above average rainfall. This has generated interest in growing summer grain and forage crops to provide ground cover, fodder for livestock, and potentially another source of grain income. BCG responded to this growing interest and established a trial in the summer of 2021–22 alongside the work undertaken by Agriculture Victoria as part of their Alternative Legume Crops Project (see article ‘New legume species as opportunistic summer crops for southern Australia’ p. 172 for those project results).


To assess the performance of summer forage options under a Victorian Mallee rainfed system. 

Paddock Details

Location: Woomelang

Nov–Mar rainfall: 153mm

Soil type: Clay loam

Paddock history: 2021: Vetch brown manure

Trial Details

Crop type/s: Refer to Table 1

Treatments: Refer to Table 1

Target plant density: Refer to Table 1

Seeding equipment: Knife points, press wheels, 30cm row spacing

Sowing date: 1 November 2021

Replicates: Four

Termination date: 4 April 2022

Trial average biomass yield: 0.82 tDM/ha

Trial Inputs

Trial managed as per best practice.


A replicated field trial was sown using a complete randomised block trial design. The trial received no irrigation and was grazed with a lawn mower on 4 February 2022. Assessments included establishment counts and crop biomass. Feed value was not assessed. 

Results & Interpretation

The trial was sown into a full soil water profile and the site received 47mm of rainfall eight days post-sowing. Crop establishment was variable and not all species within the commercial mixes established (Table 2). A potential explanation could be soil temperature, because soil temperatures less than 16 degrees C limits germination of some species (Christy et al., 2022). 

Limited rain fell in December post establishment (Figure 1). Storm activity delivered rain in January that kept plants alive but high maximum daytime temperatures constantly dried out the top 30cm of the soil profile (observations from the field, data not recorded). As a result, not much crop biomass was produced (Figure 3) and there was poor recovery after the grazing treatment was applied on 4 February 2022 (Figure 2).

The best forage option in terms of biomass production was the commercial mix 2 which produced an average of 0.96tDM/ha at point of flower (Figure 3). It is advised to leave 1–1.5tDM/ha of plant residue in a paddock to provide adequate ground cover to protect the soil from wind and water erosion, so growing forage crops at Woomelang in the summer of 2021–22 would not have sustained grazing for livestock without a negative impact on soil health (Frischke and Jolly, 2020).

Commercial Practice and On Farm Profitability

Chase the rainbow?

The 2021–22 summer had the perfect lead up for exploring the viability of growing forage crops over summer. There was an active La Niña event occurring, the forecast was for above average rainfall over the summer period, and the soil profile at the site was full heading into the summer cropping season thanks to isolated storm events. As the results have demonstrated however, a full soil profile at the start of summer was not enough for the summer cover/forage crops to produce adequate biomass for soil cover and livestock grazing. Even if the forecast indicates a wetter outlook, summer rainfall is too unreliable in our environment as it is predominantly delivered via storm activity which is very spatially variable; you either get lucky or you do not. Even if adequate rain (i.e., via irrigation) is received, high daytime temperatures and high evapotranspiration rates in summer are likely to be prohibitive to plant growth. As seen in the Mallee sites under Agriculture Victoria’s Alternative Legume Crops Project, the species investigated there received irrigation at key times to alleviate terminal water stress and only managed to generate 1tDM/ha of biomass at harvest (Delahunty et al., 2022)


Weed management Depending on the summer crop, weed management options can be limited. There are no options for controlling broadleaf weeds in species such as Sunn Hemp and commercial mixes. As seen in the trials, heliotrope can produce several generations in one season and compete with the sown summer crop/s for nutrients and water. Impact on winter cropping program Whilst not measured in this research, numerous BCG trials (1999–2012) have demonstrated the importance of managing summer weeds for preserving stored soil moisture (Browne et al., 2011) and available soil nitrogen (Browne et al., 2012, 2013). Thus, summer forages have a limited fit, if any, in the Victorian Mallee environment.


Browne C., Hunt J., Whitbread A. and Mowat D., 2011, Conserving moisture during summer, 2010 BCG Season Research Results, Birchip Cropping Group Inc, Birchip, p 30. Browne C., Hunt J. and McBeath T., 2012, Conserving moisture during summer, 2011 BCG Season Research Results, Birchip Cropping Group Inc, Birchip, p 22 Browne C., Hunt J. and McBeath T., 2013, Setting up your season: Conserving moisture during summer, 2012 BCG Season Research Results, Birchip Cropping Group Inc, Birchip, p 19 Christy BP, Delahunty AJ, Norton SL, Wallace AJ, Riffkin PA, O’Leary GJ and Nuttall JG, 2022, New legume species as opportunistic summer crops for southern Australia – Part 1: Environmental suitability, Proceedings of the 20th Agronomy Australia Conference, 2022 Toowoomba Qld [accessed 23 January 2023]. Delahunty A., Wallace A., Norton S., Riffkin P., Christy B., Brand J., Henry F., Perry E., Clancy A., O’Leary G., Walker C., Fanning J., Silwal S., Partington D. and Nuttall J., 2023, New legume species as opportunistic summer crops for southern Australia, 2022 BCG Season Research Results, Birchip Cropping Group Inc, Birchip. Frischke A. and Jolly S., 2020, Value of standing crops for lamb production and soil protection, 2019 BCG Season Research Results, Birchip Cropping Group Inc, Birchip, p 162.


This research was supported by Agriculture Victoria and funded by BCG members through their membership.

We thank Warakirri Cropping for hosting this trial.

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