Sowing oats early - yes or no?

By Callen Thompson, Senior Land Services officer – Mixed Farming

“How early can I sow my oats?” is a question I get asked regularly at this time of year. When I first started out as an agronomist I would consult my winter crop variety sowing guide and answer “The second week of March”.

To this, one well respected farmer and livestock carrier of the Coonabarabran district replied: “Young fulla, the first thing you need to know about this district is that you always sow your oats in the first week of February”. Although as a general rule I don’t agree with sowing oats this early, year after year I have seen those who early sow, generally end up with more feed through winter than those who hold off. The time of the month is important in deciding when to sow, but so is the variety you use, the soil temperature and the amount of water in the soil profile.

Different times for different varieties

There is differences in sowing time for different varieties. This is due to the varieties response to day length or vernalisation (need for cold temperature to induce reproduction) requirement, it may also be a mixture of the two. Varieties such as Cooba and Eurabbie are better suited to early sowing while varieties such as Coolabah and Yarran are more suited to later sowing. The ideal sowing dates for each variety is focused on grain recovery, so if using grazing only varieties like Aladdin or Drover, or planting dual purpose varieties with strong vernalisation requirements or late maturity, sowing early should not create a problem, as long as there is moisture and it is not too hot.

Soil temperature

Soil temperature can have a major impact on germination and seedling survival. Soil temperatures over 25 degrees should be avoided. Heavy, dark clays will absorb and store heat longer than lighter soil types. Good stubble cover and available soil moisture will reduce soil temperatures. Soil temperature should be measured at 9am and at sowing depth. Keep in mind that soil temperatures could increase if there is a late heatwave. This is not uncommon in February.

Soil moisture

Good soil moisture is always important when sowing but even more so if going early. If there is limited moisture, soil will be more likely to dry out from the sowing process and therefore seed will either not germinate or partially germinate, then die. Higher ambient temperatures early in the season will increase this drying out process. High temperatures will also increase established seedlings need to transpire, which will mean they may run out of moisture quickly.

So back to the question: How early can I sow my oats? If you are sowing a grazing only variety or a dual purpose variety with a strong vernalisation requirement you could sow in the first week of February as long as soil temperature is below 25 degrees and you had ample soil moisture.

My recommendation would be to get out in the paddock, have a dig around for moisture as well as check the temperature to make sure it is below 25 degrees and falling three days in a row.

If you would like further information, contact your Local Land Services advisor or check out the DPI Winter crop variety sowing guide.