QA pressure drives PA uptake

Jim Wilson

Earlier this year the GRDC funded a visit to Australia by Scottish farmer and precision agriculture exponent Jim Wilson. Here he provides his thoughts on where the technology is heading, based on the European experience so far.

While an increasing number of Australian graingrowers seem to agree Precision Agriculture (PA) is the way of the future, there is also a feeling that there is "too much data" and not enough knowledge of how to turn it into yield increases and dollars.

In contrast to this uncertainty, Precision Agriculture has definitely come of age in Europe, where farmers are relying on PA tools and techniques for improving returns from their land.

The agronomic knowledge about what to do with the data has been well developed in several multi-year, large-scale research projects.

However, as the range of techniques expands, there is a need for agronomists to use their detailed local knowledge of paddocks and crops to select just which technique offers the best chance of a fast return on investment.

The driving force behind the take-up of PA techniques in Europe has been the long-term decline in profitability, closely followed by factors such as environmental issues and consumer demands.

Growers are no longer willing to accept consistently unprofitable areas of paddocks, and if costs cannot be reduced or yields increased, they will take those areas out of arable production and put them into grass, trees or "set-aside".

With the introduction of the "Mid- Term Review" of the European Economic Community next year and the changeover from crop to social and environmental-based support payments, this trend is set to rapidly increase as farmers enter into long-term environment improvement schemes.

They will use yield and profit maps to help them place these schemes in the poorest performing areas of the farm.

As politicians and consumers become more environmentally aware they demand that growers use less fertiliser and crop-protection products.

This is enforced by numerous quality assurance schemes growers must now comply with if they are to sell to supermarkets.

PA can help by justifying the location and rate when applying fertilisers, agrochemicals and farmyard manure.

By recording the application rate as the job is done into as-applied maps, it can also satisfy the crop recording and traceability requirements for such schemes.

Farmers" attitudes have also changed as they come to accept computers, email, the internet and mobile telephones as business tools, along with GPS in both their cars and tractors.

One of the biggest changes that tractor operators have seen is the introduction of swath guidance and autosteer, which has brought huge benefits in ease of working, timeliness and accuracy, and it has done more to convince people of the benefits of PA than anything.

One of the objections to PA has been how to make use of the information the technology generates. Many multiyear trials have now been conducted by governments and grower-funded organisations on how to turn this data into agronomic recommendations.

These projects can be viewed at or

Agricultural contractors have also been quick to see the benefits to themselves and their customers. Many use the ability to produce and use yield and variable rate application maps as a marketing tool to get and keep new customers. Farmers are happy to get yield maps "thrown in" and are unwilling to lose this service in future years, ensuring repeat business for those offering the option.

And there are still many emerging technologies. One of the most exciting developments is real-time sensors.

This is important because yield, soil and fertility maps all show what happened in the past - now we have the opportunity to influence this year"s crop as it grows and develops in response to the weather and management. In Europe this is done mainly through aerial and satellite multispectral images processed to show crop variability.

There are now a variety of commercial satellites with the ability to take an image of any area once every two days - greatly increasing the chances of getting a good image at critical periods.

In the United Kingdom this is going to be offered as a commercial service, following an 8000-hectare trial last year which showed an average £15/ha ($36) benefit, while the cost is £6/ha ($14) for two images.

Farmers will be able to download paddock images showing a Leaf Area Index map and a nitrogen application map to load into their fertiliser spreader.

Another option is the Hydro N-Sensor (, which is a tractor-mounted sensor controlling a fertiliser spreader which varies nitrogen rates based on crop reflectance and biomass. Calibrations are available for wheat and barley for yield, wheat for protein, canola and potatoes.

Fertiliser manufacturer Norsk Hydro claims an average yield increase of 3.4 percent in the UK using the yield calibration and a 0.5 percent increase in protein when using the calibration for protein.

While intensive soil sampling is still economic in Europe there is a recognised need for a real-time sensor to map soil fertility and Veris ( was the first to market last year with a pH mapping system capable of taking and analysing between five and 10 pH samples per acre without stopping.

While PA is a powerful, flexible system with an ever-increasing array of tools to help farmers and growers, unfortunately, only some of these tool will be relevant to each farm. So there is a need for two types of adviser.

To keep up to date with the new technology, data management, software and hardware will require a few PA specialists who will advise on the best hardware, software and techniques for each farm and who can process and analyse the complex data produced.

The agronomist who currently advises the farmer on the best agronomic practice for the farm will become an important part of PA, as their detailed local knowledge could identify where potential input savings and yield increases can be made.

This will involve getting to know the farm in greater detail by looking at yield and soil maps, remote sensing images and creating application maps for fertilisers and chemicals.

They will also use remote sensing images as crop scouting aids and their accumulated local knowledge to decide on the correct course of action in each zone and then generate variable rate application maps based on their findings.

For more information:
Jim Wilson, Soilessentials Ltd, Hilton of Fern, By Brechin, Angus, Scotland. UK DD9 6SB; +44 0 1356 650 307, fax: +44 0 1356 650 445,