Summer cropping options
02 Sep 2022
By Rohan Leach, Mixed Farming Advisor
What are my summer cropping options for the Central West?
High winter rainfall has inhibited some grain growers in the Central West from planting their full winter crop program. As a result, they may be interested in summer cropping to take advantage of full moisture profiles and recoup some losses with a summer cash crop.
NSW Department of Primary Industries has also released a guide for summer cropping options for central NSW. A digital copy can be found here or call in to your local LLS office and we can arrange for one to be mailed to you. The guide looks at the agronomy and cropping fundamentals of sorghum, maize, mungbean, soybean and sunflower. This article will look at some key points on growing each of those crops. In addition, this article will also provide information on Super High Oleic Safflower as a spring sown option.
In my opinion, growers should be aware that in the Central West, growing a summer crop carries more risk than a winter crop. This risk increases the further south in the region due to lower summer rainfall. Additionally, the advantages that a long fallow offer on the following crop are immense in terms of increased weed control and stored soil moisture and nutrients. However, with predictions of another La Nina this summer, some growers may judge the risk of a summer crop as worthwhile. It is important to be aware that a summer crop (even a failed one sprayed out early) will severely impact on the next winter crop as well. This is due to a reduction in stored moisture and nutrients that a summer fallow typically provides.
Figure 1: Bazley MR sorghum near Gulargambone which yielded 4.2t/ha (photo credit Pip Doolan)
Basic summer crop agronomy
For those new to summer cropping in the Central West, growers will need to be aware of a number of basics in order to grow a successful crop.
Soil water holding capacity is a key consideration for any summer crop. Soils with a high water-holding capacity (i.e., soils with a high clay content) are essential for high yielding crops. Sandy soil types simply do not hold enough water for the high demands that hot weather requires of summer crops. Consider at least 1 metre of soil moisture before sowing any summer crop.
Soil fertility is also crucial for obtaining good yields. It is important to be soil testing now, in order to plan your fertility regime to match your target yields. After the last three years, soil Nitrogen (N) will likely be low in most paddocks. Table 1 shows the N removed/tonne of grain harvested. For example, a 3t/ha sorghum crop will require around 75kg of N. Soil testing at depth will give you a greater understanding of what soil N you have stored and what this may mean for your gross margin.
Table 1: Key requirements for several summer crops (NSW DPI ‘Summer Crop Options, 2022’)
Paddock history is very important to consider, with historical weed populations and chemical use a key determinant of what you should plant. Some crops are limited in what weed control options are available, with residual or pre-emergent herbicides a necessary requirement. Be aware of chemical history on your planned summer crop paddocks as plantback periods or recropping intervals can be up to 14 months for some common herbicides.
Lastly, communicate your plans with your agronomist and rural reseller to organise your crop input requirements. Many growers may be considering a summer crop and inputs may be limited.
Sorghum
- Recommended planting soil temperatures of 16-18oC – early sown option needs > 12oC and rising for 7 days.
- For Dubbo, based off historical temperature data, October through to early December will likely be the ideal sowing time due to cool temperatures earlier and increasing frost risk if planted later (GRDC Grains Research Update – Summer crop agronomy, 2022).
- Key point about sowing time is to avoid or minimise potential for heat stress during flowering periods. Spread your risk by having different planting times.
- Match plant population and row spacing to the target yield. Refer to Table 1 for plant densities.
- Use of a precision planter is advised where possible. If yield potential is greater than 3.5t/ha, solid row spacing is advised, if less than 3t/ha, use 100cm or consider skip or double skip configurations.
- Use of a registered knockdown herbicide for crop desiccation will be needed for timely harvesting.
Sunflowers
- Small industry that requires careful marketing or long-term storage options. Seed supplies are tight this season so talk to your supplier ASAP!
- There are no herbicide options for broadleaf weeds so select your paddock accordingly. The only option for weedy paddocks is “Ausiclear 20” which is an imidazoline tolerant variety.
- Sunflowers provide minimal stubble cover after harvest, so it is recommended to select paddocks with a winter cereal stubble to maintain groundcover.
- Planting time is dependent on soil temperature (10-12oC at 8am EST) and when frost risk is low. For the CW, north of Dubbo this will be late September/early October. There is also a late planting window for late December to minimise risk.
- Sunflowers cannot compensate for plant stand through tillering, so a uniform stand is important.
- Use of a precision planter is advised where possible. Row spacing of 50-100cm or a range of skip row configurations is recommended
Maize
- Primarily grown as an irrigated crop but may be suited to some favourable dryland areas as well.
- Makes a premium silage product but variety selection is important.
- Dryland yield potential averages slightly less than sorghum as it is less tolerant of moisture stress than other summer crops.
- Single skip planting on 100cm rows is advised for drier areas so a precision planter is preferred.
- Planting window of late September/October.
Mungbeans
- Very short growing season with maturity reached in 90-120 days so more suited to situations where growers intend to double crop.
- Two potential planting times in the Central West – late September/early October and again in late December/January.
- Legume so fixes Nitrogen, but not in high levels when compared to other summer legumes.
- Can be grazed if crops fail.
- Select paddocks with a uniform soil type to ensure even ripening. Yield losses can be very high with an uneven crop with shattering at harvest a possibility.
- Narrow row spacing offers advantages in yield over wide spacings so may be a more practical option for those without precision planters.
- Avoid acid soils i.e., pH less than 5.5-6.0 will not suit.
- Insect damage will affect grain quality which can have large price penalties if human consumption grade isn’t met. Timely crop inspections and insecticide application are therefore essential.
Soybeans
- Primarily a crop for irrigated areas in the Central West. Raised beds have been shown to have increased yield compared to traditional border check layouts.
- An acid tolerant legume (ph 5.2-6.5 is ideal) which will fix high levels of Nitrogen comparative to other legumes.
- If the crop fails, soybeans make for high quality hay or grazing.
- Can perform well on a variety of row spacings from 100cm down to 30cm.
- Sowing date for irrigated crops is advised for late November/early December.
Safflower
- While safflower is primarily a winter crop, its development is controlled by a combination of temperature and daylength. That enables a flexible planting window with sowing times up until mid-September/early October without seeing significant yield penalties (GRDC Safflower Grownote, 2017).
- Sow shallow – 1.5-4.0cm deep for best results.
- Choose paddocks that are not prone to waterlogging.
- Has the ability to branch and compensate for uneven stands so target 15-25 plants/m2 in dryland conditions.
- Robust chemical weed control options. There has recently been some registration for broadleaf control in safflower so speak to your agronomist for recommendations.
- Grazing failed crops is not an option.
- Be aware that it is not a legume and has a reasonable requirement for Nitrogen.
- Two main markets, seed (for birds generally) and oil (for human consumption and industrial products). With recent improvements in the Super High Oleic Safflower breeding and increased demand pushing prices up, it may make safflower a viable option this spring.
Marketing
As with all agricultural enterprises, calculating your gross margin will be very important with you summer crops. Assessing what your likely yield may be with your agronomist and talking to your grain buyer to understand what price you receive are essential parts of the process.
The markets for summer grains are somewhat smaller in Australia with volatility and high degree of risk in their marketing. It is advised that you have contracts in place and a market for your crop before you consider sowing. It is also advisable to have good on-farm storage as delivery options for all crops are limited at harvest time.
If you would like further advice on summer cropping, please talk to your local LLS ag advisory team member.
Further resources