AFTER problematic soil types impacted the Pontifex family's bottom line at harvest, Grant and his brother Ben decided to incorporate a combination of companion cropping and intercropping to help boost struggling crops.
The brothers crop about 7000 hectares at Paskeville and on Kangaroo Island, and about four years ago they began trialling variety combinations to counteract "choking" crops growing on non-wetting sands.
"It all started to simply get some paddocks back into production," Grant said.
"The idea was to improve crop yields but also improve soil profiles, stop nutrients leeching and soil drift."
Companion cropping involves two crops growing simultaneously in the same paddock to "help each other out" with nutrients but only one crop is harvested.
Intercropping offers the benefit growing of two compatible and harvestable crops.
"Companion cropping helps nitrogen and carbon in the soil to benefit a hungry crop and intercropping offers yield improvement and drives more profit than a mono-crop," Grant said.
Companion crops show value
AN increase in yield and overall crop health has encouraged Paskeville cropper Grant Pontifex to press on with trialling different crop varieties while undertaking a new and "sometimes challenging" cropping practice.
Mr Pontifex introduced companion cropping of legumes with linseed and intercropping of broad beans and canola, on his family's Paskeville and Kangaroo Island properties.
Last year at Paskeville, about 120 hectares of chickpeas and linseed were sown in the same paddock and this season, it was lentils and linseed.
On KI, about 1100ha of kikuyu and canola, and beans and canola were sown.
"The legume and linseed are sown from the same box at the same time but the linseed becomes the sacrificial crop at harvest and is blown out the back of the header," Mr Pontifex said.
"The kikuyu is established the year before and then the beans are drilled into it the following season," he said.
"The 'beanola' crop means beans are grown for one year and the beans that fall onto the ground at harvest are left to spring up as volunteers the following year and the canola is sown into it then."
Mr Pontifex was delighted when beans sown within kikuyu yielded one tonne a hectare after previously yielding "nothing".
"It has certainly improved country that we were not getting anything on," he said.
The beans and canola intercropped paddock had a "promising" outcome, with bean yields at 300 kilograms/ha and canola at 2.4/ha.
"The canola mono-crop was slightly less at 2.5/ha so we had an overall increase in yield than if we just had one variety in a paddock," Mr Pontifex said.
"We noticed where the canola did not grow very well, the beans were able to compensate and produce a good crop.
"Basically, intercropping helps when one crop gets choked out because the other one does well."
Mr Pontifex said when selecting varieties to intercrop, commodity size was paramount.
"The crops have to be separated at harvest," he said.
Stopping the spread of ascochyta was also a main driver for companion cropping of chickpeas and linseed, Mr Pontifex says.
He said the linseed crop limited the disease's spores from spreading across a paddock.
"Disease pressure in chickpeas can be very problematic so this is another lever for us to limit its impact.
"The linseed also helps to create more residue as a summer cover because linseed is quite high in carbon and the stubble takes a few years to break down."
Mr Pontifex said despite there not being a high yield benefit, he hoped to gradually improve the condition of his soils.
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