CENTRAL Queensland farmer and agronomist, Kelly Becker, her husband Scott and Scott's parents Norman and Desley grew an irrigated corn crop this season that went just shy of yielding 10 tonnes/hectare on their Theodore property Paranui, despite sowing it into the farm's least fertile soil.
The farm ranges from heavy black clays and melon-holed brigalow to sandy forest country.
They sowed 34ha of PAC 727 in mid-February in the sandy loam part of the property under a Southern Cross centre pivot irrigator they purchased in 1996.
"The soil is probably best described as a hard-setting sandy soil, which brings with it inherent difficulties such as getting crops to emerge well after planting, poor root structure during the crop's life and low soil fertility.
"It just needs to be managed correctly to be able to grow crops well," Mrs Becker said.
At harvest in mid-September the crop yielded 9.9t/ha. The grain was contracted to Defiance.
"It finished the season with a big blocky grain size, which the processors like. It potentially could be very good for silage too, with a very vigorous growing habit," she said.
Mrs Becker said the established plant population was 70,000/ha with "very good" evenness of flowering and "excellent" seedling vigour.
The property has changed substantially since it was acquired by the Beckers for grazing in the 1930s, with a program of development building a diverse and sustainable business.
They added irrigated cropping to the enterprise mix in 1983 by using water from the adjoining Dawson River.
Mrs Becker said they were diversifying their risk and keeping up with the times by "using current best-management practices such as minimum till and precision ag".
This year's corn was grown as a cash crop to supplement the other business activities at the 3117ha property, which now includes cattle breeding and finishing, as well as irrigated and dryland cropping.
"We grow oats to feed the steers and round bale Rhodes grass hay for weaners and as a drought reserve," she said.
"Our objective has been to plant the cash crops under the pivots, which have produced a wide range of crops like lucerne, wheat, sorghum, corn, mungbeans, peanuts and sesame, which have been grown in the past.
"But with the limited fertility in the sandy loam soil, it can be challenging at times."
The crop was sown into a full profile of moisture at a rate of 72,000 seeds/ha using a MaxEmerge vacuum double-disc opener on 1-metre rows.
Pre-plant fertiliser was made up of a customised NP(20) K(30) SZ blend based on soil tests with further urea being incorporated in-crop via side-dressing and fertigation through the pivot.
The Beckers' chemical application for weed control was Atrazine 900 WDG at 3.3 kg/ha with one inter-row cultivation.
"We are unable to use metolochlor for grass control due to the sandy soil, but with the split applications of Atrazine and the inter-row cultivation, the crop did remain fairly clean for weeds."
Looking to the future, the Beckers are considering planting this season's corn crop in mid-to-late January to help obtain a quicker dry down for harvest.
They are looking into growing Pacific Bio Fumig8tor to help manage their nematode numbers in their paddocks and help with nutrient cycling in the sandy soils.
Neil Lyon
National machinery writer for Fairfax Agricultural Media.
National machinery writer for Fairfax Agricultural Media.
