Spring sowing crop options - getting the best results

Take home messages

• If you currently have an unsown paddock, sow something as soon as it is trafficable - earlier sowing means maximising vegetative growth which provides important components for yield (tillers, roots, etc.).
• Winter habit crops for grazing or grain can be sown from mid-August onward with very little risk of bolting due to not satisfying the vernalisation requirement.
• Sow with fertiliser, especially if phosphorus (P) status of soil is unknown.
• Autumn sowing of winter crops is the priority. If a spring sown crop is impacting on ability to sow in autumn reconsider its value in your system.
• Spring sown cereals, especially barley, are an option if you have a situation where winter sowing wasn’t possible. Their final yield however, is heavily dependent on the spring finish, and therefore, variable costs must be kept to a minimum to achieve a respectable gross margin.

Spring sown barley and wheat

The majority of wheat and barley is sown during April to June to maximise season length and target the onset of flowering and grain fill after the major risk of frost has passed and importantly before the onset of high temperatures and decreasing soil moisture. There is no reason why a spring sown cereal, especially barley, cannot achieve reasonable gross margins from a spring sowing but it carries a lot more risk as the weather at flowering and grain fill has a far greater effect on final yield and grain quality of spring sown crop than for autumn sown crop.

Opportunities:

• Utilise unsown paddocks with a crop that won’t disrupt the rotation.
• Control of resistant ryegrass with a non-selective herbicide which takes the pressure off Group A, B and K chemicals.
• Lower input costs compared to a winter sown cereal.
• Utilise existing varieties such as Oxford, Planet and Westminster which are all spring varieties and have produced the highest yields in spring sown trials.

Threats:

• Requirement to wait for the right sowing conditions after winter which could push the sowing date later than wanted.
• Dry spring conditions leading to moisture and heat stress at flowering and grain fill which produces a low yielding crop with poor grain quality.
• Spring active pests such as aphids may transfer Barley Yellow Dwarf Virus (BYDV) to newly merged cereals which can have a significant impact on crop health and eventual yield.
• Cereal agronomy needs to be adjusted to reflect the shorter growing season length. This requires changes in sowing rate, nitrogen (N) fertiliser rate and timing and foliar fungicide use.

Spring sown winter canola

The vernalisation requirement of winter canola allows it to be sown in spring, carried through summer and taken through to harvest the following year. Spring, summer and autumn grazing opportunities have seen this rotation become a viable option especially for mixed farming operations in the western district of Victoria and Tasmania. However, the yields produced over the last few years have been extremely variable, usually due to dry spring conditions combined with late grazing (failure to recover biomass), inadequate nutrition, and more recently the chance of virus infection from aphids.

Opportunities:

• Utilise unsown paddocks or a pasture back into a crop rotation in place of a dedicated forage brassica crop.
• True ‘dual purpose’ crop option for mixed farmers.
• Crop establishment in warming soils with less pressure from slugs.

Threats:

• Dry conditions after sowing which cause sub optimal plant numbers.
• Summer active pests such as green peach aphids transferring Turnip Yellows Virus (formerly Beet Western Yellows Virus) which can have impacts on crop health and eventual yield.
• Dry spring conditions leading to moisture stress to finish a high biomass canola crop.
• Lack of robust ryegrass control options in long term cropping paddocks can lead to ryegrass weed seed blowouts.

Spring sown linseed

Spring sown linseed, which however performs better sown in the late autumn, can nevertheless provide an option for paddocks that remain unsown in the current 2017 season.

Opportunities

• Broadleaf oilseed crop that provides good in crop weed control options.
• Price of product can hit highs when supply is low and demand is high.
• Can provide low residue crop stubble to sow into the following year (but it can be tough stubble!).
• Harvest timing is unlikely to impact an autumn sowing program because as a cool season crop it matures rapidly as it heats up.

Threats

• Price currently driven down by high supply, low demand.
• Heliothis grubs need to be managed closely late in season as they can cause large yield losses quickly.

Sunflowers, safflower, buckwheat, millet, grain sorghum and maize

Other summer grain options such as sunflower, safflower, buckwheat, millet, grain sorghum and maize have been trialled in the southern Victoria high rainfall zone (HRZ) with mixed results. These crops are often high biomass, big water and N users and if planted in the wrong year, can provide disappointing yields. Grower experience in the area would suggest that breaking even in cost and return is common, and while less than ideal, winter crops following a summer grain crop can see gains for a few years afterward.

Opportunities:

• Good hosts of mycorrhizal fungi which can provide benefits to following crops.
• Most of these species can also provide good biomass as dedicated grazing crops.

Threats:

• Sowing dates need to be fine-tuned according to soil temperature requirements for different species.
• Finding a market for these commodities locally can be challenging.
• Harvest window can be pushed into sowing window of winter crop as it can be difficult to get sample dry enough for delivery. Hence harvested grain often requires drying.

Summer fodder options

Any summer fodder varieties with a vernalisation requirement are an option for spring sown summer and autumn fodder. These include winter habit canola, some varieties of forage brassica, and also winter wheats. Warm season grasses such as millet and forage sorghum can also provide good summer feed. As expected, production of feed from all of these crops is dependent on summer rainfall to assist biomass accumulation and grazing recovery.

The rumen of sheep and cattle do not respond well to big changes in diet. For best animal performance, providing a diverse mix of grazing options (at least two species) can reduce fluctuations in weight gain. Using a rotational grazing system across a few smaller paddocks or using temporary fences in a large paddock will reduce the impact to the animal from change in diet.

Possible spring sown summer fodder options to include in a mix are:

• Forage brassica or winter canola.
• Winter wheat (which will remain vegetative compared with spring wheat that will run up to head).
• Millet and sorghum — do not sow earlier than the end of September as they have a soil temperature requirement.

Conclusion

This paper provides a number of spring sown crop options for growers considering a spring sowing. Each option has its own set of opportunities but also threats, and therefore, each option must be carefully considered before implementing.

Contact details

Annieka Paridaen
annieka@premierag.com.au

Jon Midwood
jmidwood@sfs.org.au