Compared with the past decade, this year’s grain harvest looks like it will be a bit different at Russell and Jacqui Taylor’s 1900-hectare farm on Queensland’s Darling Downs.
The Taylors farm at Warra, north-west of Dalby, where rainfall has been about 25 per cent higher than average this year. This season’s rotation includes barley, wheat and chickpeas.
“It’s been a great season,” Russell says. “What has made the most difference, though, is how the rain has fallen. It’s been well-timed, regular and not excessive. We often receive all our rainfall in one big gulp. It’s really different this year and you can see that in the crops.”
Average annual rainfall is meant to be 580 millimetres, but in the past five to 10 years it has been far less. Russell says he can tell the environment is changing, justifying his decades-long journey to improve soil moisture practices.
“We need to make the most of water. It is our biggest limiting factor. Although as farmers there are other issues we can concentrate on first, the biggest bang for our buck is in water use efficiency.”
The Taylors began using controlled-traffic farming, stubble retention and deep-seeding practices in the late 1990s. Those early moves have gradually evolved to include more precision agriculture practices.
This has included levelling paddocks using GPS to stop ponding when big rains fall, and applying variable-rate feedlot manure to boost soil nutrient levels in levelled paddocks. Russell has been working with Toowoomba-based agtech consultant Tim Neale since 1996 to develop and implement these practices.
Russell says paddock level variations are “micro”, with the deepest dips about five centimetres. “You can look at the paddock and think it’s perfect, but these depressions hold water and don’t drain well or quickly. And, more and more, our rainfall comes in one massive event, which causes ponding.”
With a good season this year, Russell has decided to look further into variable-rate nitrogen and is considering buying a protein monitor.
By measuring protein levels in harvested grain, a nitrogen-uptake map can be built and, from that, a variable-rate nitrogen map. Generally, wheat grain protein concentrations of less than 11.5 per cent indicate that nitrogen supply was insufficient for a crop to meet its water-limited yield potential. Used with satellite normalised difference vegetation index (NDVI) data and yield maps, protein information will add another layer of detail.
“Our nitrogen rates are high,” he says. “It is our biggest input so it’s good to start thinking about that and putting it where we need it most.”
However, he is keen to point out that without good water management, these other decisions are superfluous. “It all starts with water. Rainfall is becoming less and less and, when it does come, it usually falls in one massive event. It is important and I feel justified that we began addressing this with CTF more than two decades ago.”