30 March 2023, AU: When moisture is tight it pays to make your decisions fluid.
This is the management philosophy of Benj Graham. Managing a farm at Bonnie Rock, 350 kilometres north-east of Perth where annual rainfall is around 300 millimetres, but variable, he understands the vagaries of the environment well. But his decisions are made within a larger context and fallow is a key risk management tool.
“We think it’s important to be fluid in our decisions to get the best results with seasonal variations and fluctuating input and commodity prices,” Benj says.
The farm was originally purchased by the Spark family in 1958. Benj was employed 19 years ago and has been managing the cropping business for six years.
The farm business spans more than 60km and incorporates 12,000 hectares of arable land crop and fallow and 4000ha of lighter sheep country that carries about 10,000 head.
“Our sowing dates have moved up to 10 days earlier – now between 10 and 15 April. This has been driven by the rainfall declining to around 280mm, but more summer rainfall over the last 20 years,” Benj says.
Relying on finishing rains is becoming more risky and we are now focusing on conserving summer rainfall for crop production. We are very reactive to the seasonal conditions.
This is why, over the past six years, fallow has become a key strategic tool for managing risk for Benj.
“We use the amount of summer rain as the first decision trigger to decide on what paddocks to fallow. It is then followed up with a second decision made around whether we receive significant rain around the break.”
This means that Benj focuses on capitalising crop production in good years and not missing out too much during poor seasons. He generally uses a complete brown-out fallow as part of his cropping sequence every year, fallowing a minimum of 2000ha to a maximum of 8000ha, depending on the seasonal conditions.
“From fallowing we are seeing higher nitrogen levels and achieving better weed management together with conserving moisture.
“After fallow we can successfully establish a crop on as little as eight to 12mm of rainfall, but with continual cropping we need a break of 50 to 60mm to feel comfortable establishing another crop.”
Benj is supported by Chris Wilkins from Vision Agribusiness Services in making his agronomic decisions and, more recently, has been working with Dr Darren Hughes from Laconik.
“I had been using large strips to experiment with various inputs and cropping practices, but the Laconik approach that captures paddock scale variability and is easily integrated into our machinery’s data management systems saves time.
This makes much better use of our machinery capacity, capturing data in response to more spatial and seasonal variability to inform our decision-making.
Benj is part of GRDC’s National Grower Network fallow project in partnership with Laconik. Following various fallow types, 2023 will see the second year of data collected as the sites are cropped.
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