Trials in southern New South Wales and northern Victoria have shown that double cropping success relies on quick and seamless transitions between the winter and summer crop phases, and the results are helping growers weigh up the benefits of the approach.
The trials feed data into a Decision Support Tool (DST) for Double Cropping, which provides an easy way for irrigators to assess the gross margins of different rotations, attribute an average water price to those rotations and customise inputs, yields and commodity prices for their own circumstances.
The research was made possible through significant contributions of growers through trial cooperation and investment by the Grains Research and Development Corporation (GRDC). The project Correct Crop Sequencing (Double Cropping) was conducted by NSW Department of Primary Industries (DPI) at the Yanco Agricultural Institute (YAI) as well as the Irrigated Cropping Council (ICC) in Northern Victoria.
NSW DPI research and development agronomist, Tony Napier, and his team conducted large-scale field trials of irrigated winter and summer crops at YAI’s Leeton Field Station.
“We ran trials for two and a half years, or five seasons, which focused on wheat, canola, barley, faba beans, soybeans, maize and cotton rotations and their gross margins to inform and develop the DST,” Mr Napier said.
Researcher Damian Jones said individual crops within a double cropping system can be quite profitable and therefore double cropping does make financial sense, but enthusiasm, infrastructure, equipment, profitable crops and capability have to be available.
“Double cropping has been practiced previously across the irrigation zone, but widespread adoption has been hampered by numerous issues such as water availability, commodity prices and profitable crop choices,” Mr Jones said.
“This project was established to re-visit the study of the profitability of some common double cropping rotations and new techniques to accelerate harvest and or sowing.
“On the other hand, the trials also show that sometimes making the difficult decision to ‘pull the pin’ and not proceed with double cropping is the best option.”
“Results from the rotational trials to date show that cotton is the most profitable crop and by a significant margin. The cotton crop returned a gross margin of $4,765/ha or $477/ML compared with maize at $1,692/ha or $176/ML and soybeans at $933/ha or $125/ML,” Mr Jones said.
“Winter cropping gross margins are competitive with summer crops on a $/ML basis. Faba beans had the highest gross margin of $1,491/ha or $481/ML followed by wheat with gross margin of $723/ha or $222/ML.
“A potential weakness of the gross margin comparison is the fluctuation in commodity prices. In the 2015 season, faba bean prices were around $450/t while the prices in 2016 were closer to $220 to $240/t, which made a large change to the profitability of faba beans from one year to the next.”
Double cropping success relies on quick and seamless transitions between the summer and winter crop phases. The Victorian component of the GRDC double cropping project focussed on some of the technical barriers to adoption.
“The trials found that techniques such as windrowing and equipment designed to bring forward harvest and manage stubble make the transition easier,” Mr Jones said.
“Double cropping is not for everyone. It takes planning and personal drive and in some situations, specialised machinery and infrastructure, however the DST will go a long way to help address some of the barriers to adoption.”