Investigating the cost of achieving marginal increases in yield, in an effort to maximise gross margin per hectare, Boggabri grower Andrew Watson stumbled across the immense value of preserving beneficials in cotton production.
Returning to run his family’s farming enterprise Kilmarnock Farming Pty Ltd in the Upper Namoi region of NSW, Andrew began to look closely at the cost of trying to achieve high yields through high levels of input. He questioned if this was necessarily the best strategy for driving the long term profitability and sustainability of their operation, particularly with the availability of Bollgard II varieties which provided protection against the cotton pest moth Helicoverpa spp. He was not alone in his thinking and began to work with other like minded growers, in particular Ben Stephens the former manager of Auscott Narrabri, to find if they could strategically manage their cotton IPM through fruit mapping. Initially they were interested to determine if myrids were actually impacting yields. Using fruit counts and plant mapping they began to adjust their management of myrids and then other insects in response to plant condition. For example Andrew says that “at this stage of the season (late January 2011), we have approximately 300 squares and 100 bolls, so if we lose some fruit it may not actually damage yield.
“We avoid spraying with pesticides as this significantly damages the population of beneficials.
“Furthermore if we spray, we are likely to end up ‘flaring’ mites! With whitefly and aphids, they are there, but not infesting to levels that cause damage.”
Realising that beneficials could contribute significantly to his insect management, Andrew looked at research conducted on how far beneficials can travel to cotton from refuge areas such as tree corridors and native vegetation.
Right: Insects beneficial to the predation of cotton pests can be found throughout the Watson’s crops – made possible because no sprayed insecticides are used.
Andrew says that as his understanding of beneficials increased and the need for spraying decreased, he began to look at ways to manage and promote these non crop areas on the property.
Drawing on his knowledge of beneficials and whole farm management principles he had learned from a Grazing for Profit program, he studied the farm layout and the distance that tree corridors and vegetation areas were from cotton and how that related to spraying in cotton.
“It helps we are a relatively small farm so distances across our cotton area are not too great,” he said.
His family had already spent many years working on the principles of whole-farm management and long term sustainability prior to Andrew returning to the farm.
They had initially established tree belts for spray drift management and as the enterprise is a mixed farm operation, ease of management was needed for the grazing, so laneways to move stock between grazing areas was essential.
Andrew explains that these lane-ways were the basis for extensions of tree lines and wildlife corridors, some of which link up to a central area of buildings and machinery on a small hill surrounded by trees and vegetation.
“We’ve been involved in research projects with the UNE and Greening Australia, which involved planting different areas to tree and vegetation belts,” Andrew said.
“Riverine environment was important to my mother Robyn and she, in conjunction with the Boggabri Landcare group, removed willow trees from the 17 kilometres of river frontage we access and re-established native vegetation along the banks to stabilise them. She is now working on the river frontage of my brother’s farm downstream.”
Although these non crop areas were important to the farm Andrew says that it is impossible to determine exactly how these environmental improvements impacted on cotton production.
“It was really hard to quantify the value of beneficials, or to know the value of providing habitat to encourage beneficials,” says Andrew.
“For example we put bat houses in some of the trees to encourage bats as we know bats will fly out and feed on insect pests, consuming up to 100 percent of their body weight in a night, but it is difficult to measure that benefit.”
That is where benchmarking came in to the story. Andrew explains that he had been part of a benchmarking group for a number of years which has helped him to quantify his low input system that relies heavily on beneficials, in comparison to other growers using different production strategies.
“With benchmarking and getting more information about other farming systems, we have been able to get some estimate of the value of beneficials,” he said.
“Data from the Namoi and Gwydir areas indicate that yield alone is not necessarily an indicator of gross margin per hectare.”
The farm contracts local agronomist Rob Weinthal of RAW Agriculture to monitor the crop and assist in management decisions. They consider the condition of the cotton plants in each field and look at insect counts (including beneficials).
Andrew records all of this information in a spreadsheet, comparing current conditions to historical averages to try to predict what might happen in the crop and make informed decisions about spraying and insect management. The result has been that Kilmarnock cotton has not been sprayed with insecticide for three seasons in a row, this is shaping up to be the fourth.
Results from the last few seasons showed that although the property’s yields averaged 10.5 bales/ha, the economics highlighted they were making as much money as other high input, higher variable costs growers who were growing as much as 14 bales/ha.
Contributing to the success of his system is a conservative approach to all levels of spending on the property.
“Keeping costs to the minimum required extends into fertiliser management and even machinery costs. We look closely at tailoring nitrogen input to yield and have gone to wider equipment,” Andrew said.
As part of Monsanto’s Bollgard II® licence requirements, pigeon pea is grown as a refuge crop and where beneficials appear to be playing some part in natural pest management. Although there are generally high levels of Helicoverpa spp in the pigeon pea which impact on yield, the Watson’s still produce around 1t/ha which they sell and recover approximately half the cost of growing the refuge crop each year.
Andrew points out that the use of economic analysis and utilising the ecosystem service provision of beneficials in IPM, is not just used in their cotton production system. He says that they are also applying these principles to their broadacre farming.
Right: Andrew in another promising crop (in January this 2011), with the native vegetation that has become integral to his farming system in the background.
The story does not end there.
Driving around the property Andrew points out areas that he plans to redevelop sometime in the future. This includes tree corridors on the outside of grazing lanes (to prevent stock damaging the trees) that will join the farm’s central area to the river vegetation, and a section of irrigation fields is to be rebuilt for lateral irrigation, allowing for connection of two separate stands of native timber once the need for channels is eliminated.
“This is a journey, and I hope I never stop looking for new and better ways to do what we do in all senses of the words, be they economic, environmental or related to quality of life,” he says.
Andrew’s suggestions to growers wanting to develop their environmental management to gain greater benefits from ecosystem services such as natural pest control are straightforward.
“Do your analysis, benchmark yourself against other people then start to look at what you are doing.
“Look at it carefully, if my variable costs are $900/ha less than someone else, they have to achieve approximately 2bales/ha (at $450/ bale income) than me to make more money than I am.
“Then, trust your beneficials. It is hard to say ‘we have spiders in our crop so we are not going to get yield loss’.
“However, when you are benchmarking yourself against other people and looking at what you are doing, then you can assess your IPM and overall production strategy against profitability.”
Article by Chrissy Brown originally published in CRDC Spotlight Magazine
