Jess
Lowenberg-DeBoer, SSMC Director
Introduction
Australian growers are finding practical and profitable uses for precision agriculture, but the uses differ somewhat from those common in the US. Yield monitoring is relatively common, but as in the US many yield monitors are not linked to global positioning systems (GPS). High soil testing costs have discouraged US style variable rate fertilizer and growers are searching for alternative ways to develop variable rate application (VRA) fertilizer recommendation maps. Because of severe soil compaction problems, GPS guidance for controlled traffic is considered by some to be the best starting point for precision agriculture.
This article is a brief glimpse at the current status of precision agriculture in Australia. It is based on my recent two-week trip (Feb. 1-15) to that country. I participated in the Australian Society of Agronomy annual meeting in Geelong, Victoria, and met with growers from the Southern Farming Systems (SFS) group near Geelong; farmers near Moree, New South Wales; staff of the Australian Center for Precision Agriculture, Sidney; CSIRO staff at the Waite Campus, Adelaide; and members of the Southern Precision Agriculture Association (SPAA) in north of Adelaide. The Australian Society of Agronomy had a plenary session on Precision Agriculture and two contributed paper sessions. Abstracts are available at the conference website:
http://www.cdesign.com.au/agro2003/pages/home.htm.
Autosteer and Controlled Traffic
The most surprising aspect of precision agriculture in Australia is the rapidly growing use of self-guided steering systems in grain crops. Automated steering incorporates GPS guidance technology that controls steering; the driver only has to steer when turning at the ends of the field. In the US, automated steering is used mainly on higher value irrigated crops, such as vegetables and cotton. The initial investment of US$10,000 to US$60,000 has raised questions about the potential for self-guidance in US grain production.
In Australia growers are turning to Autosteer to help them implement controlled traffic. The clay content of the soil and the lack of freezing and thawing make many Australian soils particularly susceptible to compaction. Controlled traffic limits farm equipment to specific paths (also known as tramlines) through the field. Autosteer allows growers to follow the same paths from operation to operation, from year to year, even if tillage or weather has obscured the wheel tracks. Lightbars are a lower cost option used by some growers, but typically result in wider path areas becoming compacted.
In the state of Victoria, on the Southeastern coast of Australia, growers have a special form of controlled traffic known as “raised beds.” This is not a high rainfall area (average about 20 inches annually), but it does suffer from water logging at certain times of the year. To keep crops up out of the water, Southern Farming Systems (http://www.sfs.org.au/) developed a method of building raised beds 6 to 10 inches high and 4 to 6 feet wide. Farm equipment traffic is limited to the paths between beds. By maintaining pass-to-pass accuracy, compaction from equipment is reduced, increasing the longevity of the raised beds and the subsoil. With reduced water logging, raised beds can more than double wheat yields in this area. Automated steering helps growers achieve the driving accuracy required to improve yields and maintain beds from year to year.
Autosteer can also be applied to improve the application of non-selective herbicide (hooded sprayers) in “wide row” chickpeas. In this context, “wide row” means approximately 30-inch rows instead of the 7 to 10 inch drilled rows for conventional production. Wide rows are used as an alternative in dealing with herbicide resistant weeds. Because these growers are accustomed to drilled crops (e.g. wheat, canola), they find row cropping difficult for large acreages. Autosteer helps reduce the stress and fatigue associated with herbicide application in row crops.
Using Yield Maps
For the 2000 harvest, there were about 800 combines equipped with yield monitors in Australia. About 500 of those yield monitors are in the low rainfall, dryland wheat area of Western Australia. In most of the world, yield monitoring seems to catch on first in higher rainfall areas with better yields. Two hypotheses about the concentration of yield monitors in Western Australia include: a) the large size of fields and farming operations in the region (1000 acre fields are not unusual) and b) the series of good seasons in the late 1990s that led farmers in that area to buy new combines.
All new combines in Australia are imported and most come with yield monitors as a standard option. However, GPS is not considered standard equipment and must be purchased extra. The number of combines with GPS seems to vary from region to region. A John Deere dealer from Geelong, Victoria, said that about 70% of his customers have GPS. A researcher from Western Australia estimated that only 10% to 25% of growers in that region have GPS. Similar to the rest of the world, Australian farmers struggle to find ways to use data from yield monitoring and other precision agriculture technologies.
One of the unique uses for yield monitor data in Australia may be to help pick the best places to plant trees. In spite of the fact that Australia is the driest continent, water tables are rising in many agricultural areas because shallow rooted annual grain crops do not use water that has penetrated deep into the soil profile. Because the ground water is often salty, salinity problems are quite common. One of the ways to fight salinization is to plant trees and other deep rooting perennials that take water from deep in the soil. Some estimates indicate that 30% to 50% of the landscape may need to be converted to deep rooting plants, such as trees and bushes to keep salinization under control.
Mike Wong, a researcher with CSIRO in Western Australia, has developed a method for using yield maps, remote sensing, soil types and other data to help choose those areas to be planted to trees. CSIRO is the Commonwealth Scientific and Industrial Research Organization, which is a government research group similar to the USDA Agricultural Research Service (ARS) in the US. A key layer in his geographic information system (GIS) is gross margins from cropping. He found that some areas of fields studied rarely produced enough to cover production costs, while other areas consistently produced profits. He suggests planting trees and bushes on those areas that are rarely profitable. An abstract of his paper is on the Australian Society of Agronomy website listed above.
Variable Rate Fertilizer
Many Australian farmers apply dry fertilizer with air seeders. It is relatively easy to modify this equipment for variable rate application. More difficult, however, has been coming up with fertilizer recommendation maps. Soil testing in Australia is too expensive for the kind of intensive soil sampling used in the US and Canada. In Australia, soil lab analysis can cost from $25 to $70 per sample depending on the type of analysis.
Some growers find that top soil depth is highly correlated with yields and nitrogen requirements. Mike Smith, Moree, New South Wales, has divided his fields into three nitrogen requirement zones based on soil depth. Initially he measured soil depth manually with a “push probe” (like a tile probe), but he found that soil electromagnetic conductivity (EC) measures using Veris equipment are a very good surrogate for soil depth.
“Veris data is very good for measuring soil depth,” Smith said, “That is why I stopped using the push probe.”
EC may turn out to be easier to use in Australia than in North America, because two of the key problems in Australian soils, salinity and compacted layers, are relatively easy to identify with EC data.
Other farmers are using yield history, topography, soil types, and soil color to create management zones. Brett Whelan, [Australian Center for Precision Agriculture (http://www.usyd.edu.au/su/agric/acpa/)] has developed a statistical method for creating such zones. He is testing this method with growers in on-farm trials.
GRDC Research Funding
One of the key sources of research and development funding for precision agriculture in Australia is the Grains Research and Development Corporation (GRDC). This is a grower financed organization which operates in partnership with the Australian federal government (www.grdc.com.au). It differs from the check off financed commodity groups in the US in several ways. The “grains levy” paid by Australian grain growers is mandatory; US "checkoff" are at least theoretically voluntary. The money raised by the levy for research and development is matched by government funds. There is no general matching of US checkoff funds. Review of project proposals is done by a committee of growers, researchers and agribusiness representatives. Because the US checkoff funds are raised entirely from growers, the public and research community do not have a voice in how the funds are spent.
The GRDC has recently started a five year $3 million project (5 million Australian dollars) to support the development of precision agriculture for the Australian grain industry. In his talk at the Australian Society of Agronomy conference, Chris Price of the GRDC identified four key factors needed to propel precision agriculture in Australia to the next level. These are factors familiar to US precision agriculture:
1)
development
of diagnostic tools,
2)
farm-level
software for integration and analysis of data,
3)
support
for precision ag farmer groups, and
4)
training
for farm consultants, agronomists and crop advisors.
Partners in the GRDC effort include the Australian Center for Precision Agriculture (ACPA), the Victoria Natural Research and Environment Department, CSIRO Land and Water, Southern Farming Systems (SFS) and the Southern Precision Agriculture Association (SPAA). The SFS and SPAA are among the many farmer self-help groups organized in Australia to help farmers with new technology and improve farm management. Australia has largely dismantled its public sector extension service; farmer groups handle so much of what extension does in the US.
Precision Viticulture
The application of precision agriculture in Australia that seems to make the most economic sense is precision viticulture. This is an industry with high gross revenue per acre (often > $10,000/acre) and enormous quality premiums with top end wines selling for over $100 per bottle. Rob Bramley, CSIRO Waite Campus, near Adelaide has been developing methods for linking soil characteristics, with cultural practices, and wine quantity and quality. His research is funded by a combination of government and wine industry sources. Several of his papers can be found on the CSIRO sustainable agriculture website at:
http://www.per.clw.csiro.au/research/agriculture/southern/publications.html
Bramley said that wine grape management in Australia is particularly adapted to precision agriculture because it is 99% mechanical harvest. In California and France hand harvest is used for high quality wine grapes. Site-specific management of existing vineyards poses special problems because of the permanent placement of vines and trellises. New vineyards are being designed and planted with site-specific management in mind.
Conclusions
The development of precision agriculture in Australia shows once again that the uses of this technology are site-specific. Australian farmers are looking to automated steering systems to help them deal with soil compaction and water logging. One of the key uses of yield maps might be to help identify which areas should be taken out of grain production and planted to trees. Electromagnetic conductivity is often a very useful tool in Australia because soil problems such as salinity and compaction are relatively easy to identify with EC data. Quality focus and mechanical harvest make the Australian wine grape sector a natural for precision agriculture management.
Identifying the site-specific uses of precision agriculture requires research. Precision agriculture is not a technology that can be easily borrowed. Finding those uses often means that researchers, farmers and agribusiness need to work together because no one group has all the expertise required. The GRDC projects, Australian Centre for Precision Agriculture, precision viticulture work at CSIRO, Southern Precision Agriculture Association and Southern Farming Systems are the kind of efforts that will make precision agriculture useful in Australia.