Dr Andrew Fletcher1, Dr Kenton Porker2, Ms Jackie Bucat3, Dr Matthew Nelson1, Colin McMaster4, Andrew Ware5, Mr Brett Masters5, Miss Chloe Rout6, Mr Thomas Jones7, Mr Rohan Brill8, Ms Rachael Whitworth9, Mr Maurie Street10, Ms Danielle Lannin-England11, Dr John Kirkegaard6
1CSIRO, Floreat, Australia, 2CSIRO, Waite Campus, Australia, 3Department of Primary Industries and Regional Development, Perth, Australia, 4NSW Department of Primary Industries, Orange, Australia, 5EPAG Research, Port Lincoln, Australia, 6Living Farm, York, Australia, 7Birchip Cropping Group, Birchip, Australia, 8Brill Ag, Ganmain, Australia, 9Ag Grow, Yoogali, Australia, 10Grain Orana Alliance, Wongarbon, Australia, 11AgInnovate, Keilira, Australia, 12CSIRO, Black Mountain, Australia
Biography:
Dr Andrew Fletcher is a Senior Scientist in Farming systems with CSIRO based in Perth. His research focuses on developing resilient farming systems that maximise productivity, profit and are sustainable.
Andrew grew up on the Canterbury Plains in New Zealand and attended Lincoln University. He completed his PhD in 2005. Andrew then completed a post-doctoral research fellowship in Gainesville Florida. He then returned to New Zealand and studied the agronomy of range of crops. Andrew moved to WA in 2012 and has been conducting farming systems research in the Wheatbelt.
Abstract:
Canola is an important crop in Australia but is a challenge to establish due to its small seed size which requires shallow sowing and often exposes seeds to marginal moisture and high temperature when sown early. A survey of Australian canola growers found that canola establishment was typically 60-80%, and that achieving suitable sowing depth was an important research priority. A series of 14 field experiments in the canola growing regions of Australia in 2023 compared the emergence of canola from shallow (10-25 mm) and deep sowing (35-50mm). The experiments used combinations of sowing date and irrigation to create 38 seed bed environments. Deep sowing decreased plant emergence by an average of 41%, confirming previous studies suggesting a decline in emergence at depths below 25mm with current genetics. At four sites, soil temperature was measured intensively during establishment. The daily maximum soil temperatures (Tmax) occurred at about 1-3pm and diurnal variation increased at the shallow sowing depth. Tmax varied between the sites according to differences in weather, soil colour and texture. At one site, near Geraldton WA, Tmax at 15mm depth exceeded 30°C in early April and exceeded air Tmax by as much as 10°C. The soil was ~4°C cooler at 40 mm sowing depth. The results demonstrate the impact of sowing depth on conditions experienced by emerging canola seedlings but indicate the soil environment is more favourable at depth. Research to explore genetic and management strategies to capitalise on deeper sowing will improve the reliability of canola establishment.