Precision farming – a global perspective

Precision agriculture (PA) allows farmers to operate more efficiently and become better decision-makers. Australian Tim Neale and Sharon Clay from the US took part in a PA conference in Potchefstroom. Annelie Coleman compiled this report.

Precision farming  – a global perspective
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Australia has helped to lead the way in the application of precision agriculture (PA), or satellite farming, which allows farmers to cater for the variability of their lands. GPS automated steering and yield monitoring signalled the start of precision agriculture in Australia in the mid-1990s. Variable rate application fertiliser maps, EC (electromagnetic conductivity) soil mapping and cost reduction formed the secondary focus.

By 2011, yield mapping, variable rate (VRT) fertilising and autosteer guidance systems were used by 22%, 8%, and 67% of Australian farmers respectively. Controlled traffic farming, which limits farm equipment to specific paths (known as tramlines), was being implemented on about 20% of farms in the country. PA consultant Tim Neale explains that yield data is not widely used in Australia. “In comparison, GPS autosteer has been implemented rapidly, driven by a skilled labour shortage and the need to use tractors more efficiently.

“In addition, rising fertiliser prices have increased interest in VRT, especially in Western Australia, Victoria and South Australia.” According to Neale, interest in precision agriculture has also increased due to the fact that machinery is often factory-fitted with equipment such as yield monitors, variable rate control and autosteer. “The price of autosteer machinery has dropped to about A$20 000 (R180 000) per tractor and the increased availability of satellite imaging options gives greater access to real-time data,” he explains.

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Moreover, improvement in technology hardware and software has given less technology-savvy farmers the opportunity to become involved. Neale adds that technology could fill the gaps in resources caused by bigger farm units and fewer farmers. “While agricultural commodity prices stay low and input costs increase, the benefits of PA are increasingly appreciated because of access to improved support systems.”

Another boost for PA comes from the demise of government-funded research stations. This encourages farmers and agronomists to conduct trials on-farm using PA equipment.


(Left to right) – Jozeph du Plessis, Tim Neale and Prof Sharon Clay. 

Telemetry and apps
Neale stresses that the demand for products and services shows that the future for PA in Australia is highly promising.
“Telemetry will be a primary driver of PA technology. New machines will have internet connectivity to their internal workings, which will benefit the manufacturer, dealer, farmer and PA consultant. Remote diagnostics and support directly into the machine is already in place and will be further developed as skilled operators become more scarce.”

According to Neale, apps for mobile devices will also play an important role in PA development. “We are already seeing manufacturers using iPads to collect data in the tractor cab,” he explains. “Cloud-based PA programs are now available and offer automated yield and image processing. With increasing automation, greater affordability and ease of use, more users will connect. “The challenge now is to get the information to the broader farming community.”

Soil compaction
Neale says there has recently been a focus on drainage and topography in the Australian minimum tillage system.
“We have problems with soil compaction because of the heavy implement and machinery traffic on fields. The damage caused by wheel passage can last for more than five years. The controlled traffic system addresses compaction and drainage problems and improves moisture absorption. It uses 50% less fuel and enhances tractor efficiency. “Beyond cropping, livestock breeders will increasingly make use of telemetry and remote management technology.”

Precision Cropping 
Prof Sharon Clay, weed scientist from South Dakota University’s plant science department, believes that PA has been seen as a set of practices that occur at the right time, in the right place, with the right management tool, using chemicals at the correct rate. But there is much more to the system than these.

“PA is often seen only in terms of soil fertility – especially nitrogen application and management – based on grid soil sampling, soil analysis and map generation. While nitrogen management is certainly an important aspect of PA, other factors also improve yield, reduce the negative impact of farming on the environment and increase the farmer’s profit,” says Prof Clay.

“In a properly calibrated system, data can be superimposed onto field maps to provide information on high- and  low-yielding zones. Such maps have been used to identify areas targeted for remediation, and to estimate profitability and partial nutrient budgets. “They can also be used for future decisions such as planting recommendations and fertiliser application, and may indicate problems needing attention such as soil salinity, waterlogging, weed invasion and herbicide carry-over.”

Applying PA in South Africa
Locklore farming’s Jozeph du Plessis, grain producer from Schweizer-Reneke in North West, cultivates dryland crops on 3 600ha. He has practised precision farming since 2001. The mainstay of his operation, maize, is rotated with soya beans and sunflowers. He started his precision programme with yield monitors and satellite imagery. In 2002 he surveyed his lands on a 1ha grid overlay, mapping the physical properties and chemical status of the soil.

Spatial features were digitised with Agleader’s spatial management system. Computerised models calculated the potential maize yield using calculated soil water holding capacity. Jozeph replaced low potential areas with pasture. Nutrient levels in each hectare were analysed and built up systematically to optimal levels, which meant that the soil could be used at its true potential.

“In 2003 we applied lime differentially using an adapted lime spreader,” he says. “Since 2004 we’ve applied phosphorus annually using a variable rate fertiliser spreader, following this with variable rate nitrogen applications in 2005 and potassium applications in 2007. “A neutron moisture meter monitors soil moisture in identified positions before planting. To manage to the low water content detected on some lands we implement a fallow system. A third of the cultivated area is left fallow for a season to conserve water. We plan to introduce variable planting rates.”

Management interventions on Du Plessis’ farm have increased his average maize yield from 2,98t/ ha in 2000 to 7,01t/ ha in 2012. Water use efficiency increased from 185mm rain per ton of maize produced to 91mm rain per ton of maize produced, calculated from a mean five-year rainfall.

Contact: Tim Neale [email protected], Jozeph du Plessis on [email protected] and Prof Sharon Clay on [email protected]