Climatic and agronomic conditions
Australian Crop Report: February edition
November 2020 rainfall was severely deficient to well below average in most cropping regions in Queensland and northern New South Wales (Map 1). While low rainfall during November allowed winter crop harvesting to proceed largely without delay, these dry conditions constrained spring planting of summer crops. Production prospects of early planted summer crops, particularly in Queensland, are likely to have been adversely affected due to the low rainfall, low soil moisture and warmer than average temperatures during November.
From November 2020 to January 2021, rainfall was highly variable in cropping regions in Queensland ranging from severely deficient to above average and average to above average in northern New South Wales (Map 2). This reflects very low rainfall totals (severe deficiency) during November 2020, below average to above average rainfall during December 2020 and January 2021 in Queensland and average to well above average rainfall in northern New South Wales.
Map 3 and Map 4 show the relative levels of modelled upper layer (~0.1 metres) and lower layer (~0.1 to ~1 metres) soil moisture for cropping zones across Australia for January 2021. Soil moisture estimates are relative to the historical long-term average (1911 to 2016) and presented in percentiles.
Upper layer soil moisture responds quickly to seasonal conditions and often shows a pattern that reflects rainfall and temperature events in the days leading up to the analysis date. Lower layer soil moisture is a larger, deeper store that is slower to respond to seasonal conditions and tends to reflect the accumulated effects of events that have occurred over longer periods.
Relative upper layer soil moisture levels in January 2021 (Map 3) in Queensland and northern New South Wales were mostly average or higher. There were some areas in both regions that were below average.
Relative lower layer soil moisture levels in January 2021 were average to well above average in most cropping regions in Queensland. Lower layer soil moisture levels were generally above average to extremely high in cropping regions in northern New South Wales (Map 4).
Soil moisture and rainfall over the entire growing season need to be considered when determining planting opportunities and crop production outcomes for dryland summer crops. Low rainfall and low soil moisture during November constrained spring planting of summer crops and adversely affected production prospects of early planted summer crops, particularly in Queensland. However, improved production conditions during December 2020 and January 2021 boosted production prospects in New South Wales and facilitated additional late summer crop planting in Queensland.
With generally average or better soil moisture levels in most cropping regions, the favourable rainfall outlook for the remainder of the growing season is likely to be sufficient to achieve current forecast summer crop production during 2020–21.
According to the 3-month rainfall outlook (March to May), issued by the Bureau of Meteorology on 4 February 2021, rainfall in summer cropping regions in New South Wales and Queensland is likely to be generally above average. There is a 75% chance of receiving between 50 and 100 millimetres in most grain sorghum growing regions in New South Wales and Queensland (Map 5).
The outlook for maximum and minimum temperatures from March to May 2021 indicates generally average daytime temperatures, and slightly higher than average night-time temperatures are likely in summer cropping regions in New South Wales and Queensland. In areas with sufficient soil moisture, these average temperatures will benefit crop growth and yield prospects, particularly for crop sown later than the recommended planting window.