Rapid advances in plant breeding, plant protection and better management have resulted in significant increases in maize yields, with northern Victoria and southern NSW featuring in record crops.
A maize crop grown on the property of Pate Agricultural at Tocumwal and harvested in March, has achieved an Australian record-breaking yield of 23.2 tonnes/ha.
A good season and some crop management strategies are being credited for the record crop, the winner of this year’s annual Australian Maize Association competition.
The 2021 competition was won by Rex James Transport at Nathalia, where Nick James grew a crop of Pioneer Hybrid PO725, yield tested at 19.7 tonnes/ha.
Owner of the Tocumwal crop, Nathan Pate, said while the record yield was from just a measured section of the crop, he was even happier that the average across the whole crop was also very high.
His regular cropping program includes wheat, canola, corn and rice. He’s been growing maize for about nine years.
The winning crop was planted on October 18, 2023 and harvested on March 28 this year.
The previous highest yielding crop was in 2022 and was 21.47 tonne/ha.
It was grown using a pivoting lateral with 6.5 Ml/ha of irrigation water supplied throughout the summer.
This resulted in a water use efficiency of 2.74 tonnes/Ml when rainfall was factored in.
AGnVET crop adviser James Murray, who provided agronomic advice, said the fertility of the paddock was very good with a deep nitrogen soil test confirming 212kg/ha of soil nitrogen (0-60cm soil).
A recent soil test measured a satisfactory soil pH of 5.7 CaCl 2, along with healthy 60 mg/kg phosphorus (Colwell) in 0-20cm of topsoil.
The field has had a history of robust inputs, along with soil amendments such as lime, gypsum and chicken litter.
The crop was sown following a 16-month fallow.
The fertility of the paddock was very good with a deep nitrogen soil test confirming 212 kilograms per hectare of soil nitrogen (0-60cm soil).
The previous corn residue was maintained from the 2021-22 summer.
Nathan has observed this to be a critical step to improving soil water infiltration after recent study tours in Texas established that groundcover is king.
Strip tilling started on September 28, 2023, in which 70kg/ha of phosphorus along with 148kg/ha of nitrogen was banded at a depth of around 200mm.
The Pioneer Hybrid P0937 was sown at a rate of 96,000 seeds/ha on 30 inch (76.2cm) spacings and emerged uniformly.
The actual field population was measured using precision planting pogo device and 94,000 plants/square metre was achieved, along with a singulation of 97 per cent.
A further 125kg/ha of nitrogen and 40kg/ha of sulphur was broadcast on October 2023 ahead of forecast rain (urea/SOA blend). On October 4, 2023, 80mm of rainfall fell to fully charge the soil profile with moisture.
It took a further two weeks for the field to get to the correct soil temperature for planting to occur.
P0937, an elite 109 CRM feed grain maize hybrid, was planted on October 18, 2023, along with 40 litres/ha of Corn Popup starter fertiliser in-row.
An additional application of urea (69kg/ha of nitrogen) was broadcast on November 23, 2023, ahead of rainfall to target the V5 growth stage of the crop. This appears to be a key timing for influencing cob girth.
The willingness of Nathan Pate’s manager, Daniel Phelan, to go the extra mile with this crop was evident when he co-ordinated a final nitrogen application on New Year’s Day when many others would have been down the river fishing or waterskiing.
A final nitrogen application of 46kg/ha was broadcast by aerial application on January 1, 2024.
A total of 388kg/ha of nitrogen was applied for the season, along with 70kg/ha of phosphorus and 40kg/ha of sulphur.
Weeds and establishment pests were managed with a post-sowing pre-emergent mix of Paraquat 250 at 2.5 litres/ha plus Dual Gold at 1.5 litres/ha plus Gesaprim 900 at 2kg/ha and Chlorpyrifos 500 at 1 litre/ha.
The field was mid-row ripped with a Gessner Centre Buster to prevent some early signs of soil water infiltration problems.
“The soil surface seems to seal up and repel applied irrigation water and trial and error has proven this to be a worthwhile temporary fix,” Daniel said.
Soil moisture probes were sourced through Brett Orwin at Schedule-IT in Finley. This was an excellent tool for pro-active irrigation scheduling so that crop stress during the growing season was not a factor.
Nathan and Daniel found that this technology was useful to reassure their own gut feelings regarding when and how much to water.
Heliothis were treated twice during the season. The first insecticide application occurred about mid-December.
A targeted application of Vantacor was applied along with a foliar shot of Boron at the V7/8 stage of the maize. Vivus Max was chemigated through the linear around Christmas to further manage high pressure heliothis numbers.
This achieved minimal grub damage to the grain.
A recent grower study tour to the United States highlighted the importance of applying fungicide around the VT timing in particular fields where corn residue had been maintained like this one.
An application of Amistar Xtra was applied by aerial application on January 5 to coincide with the tassel stage.
James noted the season has been a kind one for maize, with good early rainfall in November to January to setup a healthy yield potential.
The warmer weather didn’t really arrive until March and the corn was nearing blacklayer (physiological maturity).
A quicker than normal dry-down caught a few growers out, in particular the P0937 hybrid which has been around that 13 to 15 per cent grain moisture.
TESTING THE WATER
Grain maize was the highest-yielding and most-profitable irrigated crop tested in a project that explored the true economic yield potential of crops grown in south-eastern Australian irrigated farming systems.
However, the summer crop also used the most irrigation water.
The ‘Optimising Irrigated Grains’ project undertook more than 60 individual trials in six crops annually during 2020-22.
The trials at two major irrigated research centres — Kerang in Victoria and Finley in southern NSW — were undertaken by Field Applied Research (FAR) Australia and the Irrigation Farmers Network (IFN), formerly the Irrigated Cropping Council.
The aim of the Grains Research and Development Corporation-supported research was to identify gaps in knowledge about irrigation potential.
The other crops tested were the winter crops barley, canola, chickpeas, durum wheat and faba beans, all chosen because there is less knowledge about their upper-end yield potential under irrigation.
This is particularly important given newer germplasm, management advances and innovations in soil amelioration.
Research also evaluated crop suitability for specific irrigated regions.