As seen in the Australian Ag Contractor & Large Scale Farmer
(Sep/Oct2018 Issue).
Imagine each square meter of a farm optimised using GPS and artificial intelligence to improve crop yields. This is not a pipe dream that might be a reality in 2050. It has already happened in 1 million acres in Australia and around the world.
Agricultural engineer Dr. Graeme Cox says the reason to take precising farming down to this level of accuracy is to manage the most crucial element that affects farm profitability - water.
Graeme is co-founder of OptiSurface, which develops software for optimising field topography. He is also Engineering Director of the Queensland precision sugarcane operation, Davco Farming.
"Out of all the factors that reduce crop yield, too little or too much water has the biggest impact," he says. "Look at most yield maps and you will see this."
"Most people think crop yield is driven by nutrients, but on 95 percent of farms, nutrients run a distant second to water in importance."
"When water ponds for more than a day, crops start to suffocate. Yield losses a 5-10 percent can occur in each subsequent day of ponding. So, in a dozen days of ponding throughout the season, crop yield could be zero."
Graeme says this is the reason it is so important for farmers to focus on optimising their crops to access to water. The first priority should be for water to infiltrate as uniformly as possible, then, once soil profile is full, it is necessary to get excess water off without causing erosion.
This is what OptiSurface focuses on. It does this by optimising the field's terrain on a 5m grid across a field. Each point elevation is optimised along with all the points surrounding it, so that slopes from point to point promote even infiltration and good surface drainage.
OptiSurface is used by farmers and contractors in North America, South America, Europe, Russia and Australasia. They grow all sorts of crops - grains, sugarcane, cotton, tree crops, vegetables and pasture - which are rain-fed or irrigated.
Graeme's uncle, David Cox, came up with the idea for OptiSurface. Over several decades David developed 2500ha of cattle land into a world-leading sugarcane farm using laser grading.
He then bought another farm and decided there had to be a better way to grade the land. He discussed his idea with Graeme in the 1990s and together they developed OptiSurface.
"David loved laser grading, but with standard laser grading you can shift far more soil than required. It was important for him to avoid that as in his case, topsoil was limited," Graeme says.
OptiSurface is the next generation of land grading and requires GPS. It follows the curves of the natural landscape and moves the least amount of dirt for the desired outcome.
"It often reduces earthworks by 80 percent compared to laser design."
Whereas laser work in a straight line, GPS is three-dimensional. This means GPS knows where it is both horizontally and vertically, so you can shape the field to a curved surface and follow the natural topography more.
OptiSurface is not intended to divert catchment areas or majorly re-arrange the natural system. It works with what is already there to move the least amount of earth to eliminate ponding, promote uniform infiltration and minimise erosion.
"Typically we only move 2 cm of soil. Some areas may be more than 30 cm, but on average we keep cuts and fills small and keep to the natural flow path."
The first step is to survey the paddock. Graeme says most self-steering tractors with an RTK signal for their GPS correction can collect topographic data as they cultivate. OptiSurface converts that data into a coloured map that shows contours.
From the map comes the plan, depending on what you want to achieve. This could be four-way flow that meanders across the field or drainage one way down furrows. Or perhaps there is a high point in the middle of the field and you want two-way drainage from the high point to the ends of the furrows.
It is a very flexible process to work with a variety of landscapes and requirements. For example, if you drain water a particular direction you could flood a shed or neighboring property, so you can specify areas to keep away from. Maybe you want a minimum cut in a particular area to keep the topsoil.
OptiSurface's main parameters are the surface type, minimum slope, maximum slope and a smoothing factor. ('Smoothing' limits the rate at which slopes can change.)
Working with these factors, the program goes into calculation mode and produces a plan that achieves the aims with the least earthworks and, therefore, least cost. The design can be tweaked until a suitable approach is found.
Then the design is transferred to the tractor's machine control system via a USB stick. It then directs the scraper blade to the design elevation to cut or fill. To do this, OptiSurface works with the machine control systems such as Trimble Field Level.
While some farmers and contractors buy the software and do their own designs, most prefer an expert to do their designs. OptiSurface offers a service to do designs for them.
Many contractors are getting into moving earth to provide more services for clients and spread their workload over the year.
Graeme says OptiSurface works with the contractors at different levels. Initially, contractors may want to do just the surveys and OptiSurface staff do the designs. The contractors receive back the plan and use it to 'OptiSurface' the paddock.
"That is a good way to start as there is a learning curve to the software. After they have done a couple of paddocks, contractors may decide they can do it themselves, buy the software and become designers."
OptiSurface provides updates, training and an email support desk. It provides one-day turn around services to tweak designs.
The company takes no surprises approach to cost with the standard per hectare rate. Farmers can send OptiSurface their survey data and staff design a plan for them.
Farmers can provide feedback until they get a design they like. Once farmers are happy with the design, they can buy the control plan but there is no obligation to get it if they are not completely happy.
OptiSurface was first used on Dave's new farm and it has been commercialised since 2008.
"Laser grading has be around for 40 years and that was what everyone thought about. Then we come along and said. 'You don't need straight grades. You can do it better with curved surfaces." No one believed us.
"After a while innovative growers paid attention. After one tries, the next year the neighbor tries it, and it grows organically."
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