The Nichols family has a passion for soil health and biodiversity. Their Redbank Farming operation at Sisters Creek, northwest of Launceston, is an intense and multifaceted business.
Michael Nichols and his wife Rochelle lease the 385 ha farm from the family trust. The 170 ha of arable land is divided into six 27 ha blocks, on uniform red basalt clay to loam soil and can be irrigated in six days.
Grain production from wheat, barley and canola provides an effective break from intense horticultural cropping. Their six-year crop rotation centres on potatoes for French fries, onions and poppies in rotation with a wide variety of cereal and horticultural crops.
When herbicide resistant annual ryegrass arrived on the farm through the harvester in 2020, Michael knew he needed to get in early to prevent a ‘stop farming’ event.
“The ryegrass established under the poppy canopy, and then when the poppies died off, the ryegrass was able to set seed before harvest,” he says. “The ryegrass was resistant to Group A and B herbicide modes of action, so we needed to use other tactics to drive down seed numbers.”
Michael initially used a wick wiper to apply glyphosate to ryegrass that had emerged above the poppy canopy. In winter he applied propyzamide (Kerb, Group 3 [D]) ahead of pyrethrum, which killed 90 per cent of the remaining ryegrass plants. He has an on-going program to manage the remaining patches, including burning small areas at the gate where the harvester is cleaned down.
Another 115 ha of the property is used for grazing Angus Friesian cross weaners from a local dairy and radiata pine agroforestry, producing veneer-pruned saw logs. The family has preserved 100 ha of pristine native vegetation featuring white gum, blackwood and valuable old habitat trees that provide homes for rare wedgetail eagles and swamp harriers, amongst many other species.
The property is also home to Redbank Poultry (producing day-old chicks for parent company Nichols Poultry), a canola oil cold press, Hill Farm Preserves, North West Grain Pool grain storage and Michael’s contract harvesting, spraying and spreading business.
The canola oil press produces 12,000 L of filtered oil suitable for culinary use from about 36 t of their canola seed each year. They supply Hill Farms Preserves for their infused oils and Norfolk Bay Seafoods to preserve oysters.
About five years ago, Rochelle came up with the idea for North West Grain Pool to solve a marketing dilemma for their cereal harvest. Although farmers in Tasmania’s northwest can often grow very high-yielding cereal crops, they also face difficulties when conditions are wet at harvest.
“In some years, we simply can’t get machinery on the paddocks to harvest, and when we can, we often need to harvest grain at high moisture content,” says Michael. “This makes it difficult to supply feed grain markets on the mainland. The North West Grain Pool solves these problems by drying, storing and marketing 3000 t wheat and 500 t barley grain from twelve local grain growers to supply four local dairy farms throughout the year.”
The Nichols’ wheat yields average 11.5 t/ha (13.1 t/ha highest), barley averages 10.5 t/ha (12.2 t/ha highest) and canola yields are around 6 t/ha. They set the Australian record for canola and wheat yield in 2017 and 2018, respectively.
Michael’s WeedSmart integrated weed control program is based on a diverse crop rotation, including fast-growing cover crops and cereal break crops, optimal soil health and tillage between horticultural crops.
Crop and herbicide rotation
The central six-year crop rotation is potato – wheat – onions – poppies – pyrethrum (2-year crop), with several other crops grown for specific purposes as required. Michael considers pyrethrum the weak link for weeds because a dieback disease in the crop allows weeds to take advantage of gaps.
In time, maize will probably replace the pyrethrum, allowing the use of simazine and atrazine as new modes of action for the farm. Maize is used for strip grazing with the beef weaners and made into silage to feed the cattle in sheds during winter.
Barley is sown if the poppies fail, mustard (whole seed yellow and black varieties) is to supply Hill Farm Preserves and canola is grown once every three years to supply the cold press and help break up the soil compaction from the vegetable crops.
In two to three-month windows between crops, Michael plants fast-growing mixed cover crops of barley, mustard, peas and buckwheat. The cover crop is then sprayed out or ploughed in. The mustard variety used in the cover crop has a biofumigant effect on the soil that also helps reduce weed pressure.
Frequent cultivation of the arable area helps keep weed numbers low across the farm and reduces the reliance on herbicides. Winter grasses, such as wild oats, are fully controlled with pyroxasulfone (Sakura, Group 15 [K]) applied before planting cereals. It can be difficult to meet the rainfast requirements for glyphosate in their high rainfall area, but Michael finds the addition of ammonium sulfate (Liase) with glyphosate helps to increase uptake.
Michael uses farm record-keeping software, AgWorld, to record all herbicide mode of action applications.
Paddock recording software shows what modes of action have been applied in previous seasons.
Crop competition in grain crops
The cereal and canola crops are an important part of the Nichols’ farming system, improving soil tilth and building soil organic matter through increased microbial and worm activity.
Grain crops are sown on 12.7 cm (5 inch) row spacing with a density of 170 plants per m2. Michael ensures planting seed is large to maximise seedling vigour and early crop growth.
These crops benefit from Michael’s work with variable rate applications of lime, magnesium, phosphorus and potassium, implemented primarily to support more even production and improved quality in their onion and potato crops.
Sawdust and chook manure from the family’s poultry operation is spread on fields before potato planting at a rate of 15 t/ha dry matter spread.
The cereal crops leave a heavy, 12 t/ha stubble load, so Michael bales half the stubble and leaves half in the field.
These practices combine to create a very competitive environment in the grain crops that minimises weed germination and growth in-crop.
Stop seed set
The herbicide resistant annual ryegrass is a target for intense patch management. Michael uses a variety of tactics, including spraying out, burning and chipping affected patches to prevent seed set.
Cultivation is an important strategy to stop seed set in weeds across the arable area.