CQ winter cropping season proved challenging

The 2017 winter cropping season delivered both – a dry run of winter months and for some, a wet finish in October which hampered harvest and grain quality.

Growers, agronomists and researchers from the northern central Highlands to the Dawson and Callide Valleys reported a mixed bag of yield results with some crops holding up despite the dry and others suffering from frost or the unseasonably wet end to the season. 

Yet even in a fluctuating season some things remain constant and this year, as always, management practices proved a key tool in maximising crop performance with targeted agronomy practices, well-planned weed, disease and pest management programs, adequate soil and crop nutrition and harvest management all having an important role to play in final yield results.

As the year draws to a close, industry has been reflecting on the positives and challenges of last season to help map a path forward for 2018.

Researchers like DAF senior research agronomist Doug Sands have been busy collating results from the 2016-17 field trials and recently took part in a CQ Agronomy Roadshow to discuss some of the key findings in areas such as winter cereal agronomy, the value and longevity of deep placed nutrients and the impact of row spacing and population in pulse crops. The research work is part of a wider GRDC investment into regional agronomy.

Mr Sands said dry conditions meant only one major 2016-17 summer crop trial was conducted at Emerald however the arrival of Cyclone Debbie in March 2017 enabled many of the trial sites to be sown to winter crops.

Yields at the winter crop nutrition trial sites in the Central Highlands varied from a low of 0.5 tonnes/hectare for wheat up to 1.5t/ha for chickpeas. However, the Dawson and Callide Valleys faired a little better thanks to higher in-crop rainfall totals.

“Some of the key messages from our past 12 months of trial work include: that hot dry, conditions severely limits flowering and biomass production on mungbeans; and that plant response to the deep placement of phosphorus (P) and potassium (K) seems to be enhanced by traditional dry winters because the surface soils dry out and the plant has to rely on sub-surface stored moisture for production,” Mr Sands said.

“This works better for chickpeas than wheat if there is no rainfall after planting. The wheat’s root system is so limited by not getting enough rainfall for secondary root development that it can only access limited amounts of the resources held in the soil profile (water and nutrients).”

Emerald-based senior agronomist and GRDC northern panel member Graham Spackman, Spackman Iker Ag Consulting, said clients in the central and northern parts of the Central Highlands generally averaged yields of 1-1.4t/hectare in chickpeas and 1.2-1.8t/ha in wheat, although yields were higher in some areas.

“Most growers were happy with those yields given the dry conditions and the fact that, other than later-planted crops in the southern part of the region, harvest was predominantly wrapped up by late September/early October prior to rain events,” he said.

Mr Spackman highlighted several positives for the season, including the comparative performance of chickpeas sown into wheat stubble and yield responses in crops where P and K had been applied at depth.

“Deep P and K applications aren’t appropriate in all soils and situations. But where they are appropriate and have been applied based on soil tests, we are seeing some really good results.”

Acres Rural co-owner and agronomist Jeff York, Rolleston, said the season had been a mixed bag in terms of yields across the southern Central Highlands depending on whether harvest was finished before or after the October rains.

While the bulk of the cereal crop harvest was completed just prior to the rain, he said chickpea crops weren’t so fortunate with only around 40 per cent harvested before the onset of wet weather, resulting in moisture-affected grain.

Frost also played havoc with some crops, particularly those sown early on country adjacent to the river.

On the upside, wheat yields across the southern Central Highlands were pleasing considering the lack of rainfall during the growing season with some crops yielding up to 2.8 t/ha. Deep placement of P also yielded some positive results where it had been applied based on soil tests.

“On one client’s property where deep P had previously been applied, we saw a 20pc yield improvement in wheat [grain yield],” he said.

Further east, Moura district growers Scott and Kelly Becker, Paranui, received virtually no rain during the growing season which affected the performance of their chickpea and wheat crops but on a positive note, meant insect and disease pressure was low.

As in other areas, wet weather hampered harvest at Paranui – although most of the chickpeas were harvested prior to rain, those remaining in the paddock were affected yield and quality-wise. The rain fell in the lead up to the wheat harvest but yields and quality were reasonable considering the season.

Interestingly, there were noticeable differences in the chickpea crop yields owing to sowing dates and available moisture at planting according to Mrs Becker.

She said although the planting date spread was only a matter of days rather than weeks, the soil moisture profile dropped away rapidly as planting progressed resulting in a yield variation from just over 1.73t/ha on the earlier planted crop to just under 1.23t/ha on the later planted crop.

Now, with the winter crop harvest behind them and the summer season in full swing, central Queensland growers like the Beckers will be keeping a close eye on the skies and their paddocks as they plan for the year ahead.

The GRDC has a broad range of information to help support crop selection and farm decision making including GrowNotes – a comprehensive information product range providing regional trial results and best practice recommendations on all crops grown in the northern region.