Profiting from GPS and High Tech Farming – in the face of climate change

As published in Grower, May 2009.

Profiting from the technology is the bottom line for farmers investing in high accuracy GPS.

A three year research programme is following leading vegetable growers as they seek the rewardsof GPS and other precision farming tools. The technologies are being used to change how potatoes, onions, lettuce, sweetcorn, vegetableseed and arable crops are grown. One grower has already halved his fuel bill through using GPS.

Even simple things are making big differences. Self-steering systems allow hands-free driving. It is less demanding and more accurate.  This leaves the driver free to check equipment function, observe crop health or talk on the phone. Users (and their families) report greatly reduced fatigue and increased productivity. The trend is for new users to keep adding more units into their tractor fleets. Once they see the benefits, they can’t see how they did without it.

Twelve cropping farmers, from Mangere to Ashburton, have stepped forward. All have invested in high quality GPS and have auto-steer systems. While experience and equipment levels vary, all are enthusiastic, if wary of potential pitfalls ahead.

LandWISE manager Dan Bloomer is grateful to be able to work on the project. “We get to work with farmers who have selected themselves for the project. They are innovative and practical, and terrific contributors who are happy to share their learning with others.”

The farmers have identified particular aspects of advanced farming systems upon which they wish to focus. Issues range from “getting the systems going on our place with our staff” through “using this gear to manage my problem weeds much better” to “getting all this paddock information out of the tractor and straight into my office computer – I want to use it to make better decisions”.

LandWISE members (a Who’s Who of innovative vegetable growers, industry representatives, science providers and others) see ‘Advanced Farming Systems’ as key to improving sustainability.  For this study, LandWISE has partnered with the Foundation for Arable Research and the HortNZ Processed Vegetables Product Group. Additional core funding is provided by the Sustainable Farming Fund, New Zealand Fresh Cuts, Balance AgriNutrients, Farmlands and Hawke’s Bay Regional Council.

GPS use moves beyond driving straight lines, into permanent beds, precision weeding, spraying, and variable application of nutrients and water. Case studies will also explore data management, crop and soil sensing and mapping, and the integration of precision tools into cropping systems.

The common theme is increased profitability, while reducing Greenhouse Gas (GHG) emissions, and improving soil and farm resilience in the face of climate change. This happens with the fewer cultivation passes and reduced tractor horsepower required on a farm which can result from GPS use in crops. David Clark at Opou Station in Gisborne had his fuel tanker driver ask where else he was buying fuel. It is a longer time between tanker visits now, with fuel usage about half what it was under conventional cultivation.

Another case study farmer grows lettuces, carrots and Asian brassicas for NZ Fresh Cuts in Mangere. Chris Butler is already enjoying gains from GPS use. He has reduced tractor passes, saves time at the end of each row and expects to reduce nitrogen fertiliser inputs significantly. He anticipates improved soil properties will reduce weather related downtimes. Improved windows for field operations, together with higher efficiencies, will allow more crops per year. He says: “GPS is an essential tool for us to gain the most from our land and financial resources.”

Advanced Farming Systems is a term used to describe the integration of new technologies, often including GPS, into farming practices. The benefits of a well designed advanced farming system include improved soil health; savings on fuel, water, steel, fertiliser and agrichemicals; and reduced GHG emissions.

Advanced Farming Systems can reduce overall capital investment in farm equipment and improve profitability in ground breaking ways:
• Driving straight using GPS eliminates overlap and saves expensive inputs such as seed, fuel and chemicals.
• Reduced cultivation saves fuel and equipment and enhances soil quality, especially if controlled traffic principles are adopted.
• Reduced compaction avoids wasted energy (driving on loose soil is similar to driving uphill all day). Energy is required to consolidate a traffic base, then again to remove the compaction. Think of rippers and sub-soiling implements as large anchors which the tractor pulls through the earth, hour after hour. It is easy to grasp the energy savings possible through avoiding, or at least reducing, compaction.
• GPS guided Controlled Traffic Farming creates permanent tramlines, ‘supporting beams’ in the soil that carry the tractors. The formed tracks give better support to traffic in wet conditions. The soil condition between tracks keeps improving with time. A ‘garden’ forms between the tracks, allowing crops to grow free of compaction. It is about putting compaction where it is an asset and nowhere else.
• Advanced farming systems allow farmers to identify and manage zones separately within fields. Both soil and crop sensing tools are available. Combining crop scanning with GPS, a farmer can identify different zones, defined by ‘relative greenness’. Variable rates of nitrogen can then be applied, based on crop needs in different zones of a field. Given the high energy inputs and cost in N fertiliser manufacture, this offers large environmental and economic benefits.
• Fitted with RTK-GPS and auto-steer, tractors can return to the same precise line – within 1 or 2 cm. This allows for new systems such as strip-till cultivation, banded fertiliser placement and precision planting (all returning precisely to the same row), as well as precision mechanical weeding to within centimetres of crop plants. Advanced Farming Systems are changing the face of farming. Users are enthusiastic about the gains made possible and the improvements still to come in many aspects of their cropping.

To learn more about Advanced Farming Systems and LandWISE events, see
LandWISE has worked with advanced farming systems in Hawke’s Bay and New Zealand-wide since 1999.

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