As printed in December Grower

James Powrie and Dan Bloomer LandWISE Inc.

Four tonnes less soil is going to the packhouse from each hectare of potatoes. It’s a result pleasing the team at A S Wilcox in Pukekohe.

Over the past two years A S Wilcox has been working on a controlled traffic system for potatoes and onions.  Helped by high accuracy GPS guidance, they want to improve soil quality and reduce cultivation costs by keeping field traffic to planned tracks.  They have seen beneficial changes in soil condition since reducing compaction and cultivation. They are now capturing the benefits through 45% less soil being transported to the packhouse. They have reduced transport costs, reduced washing plant time and energy and have much less waste soil at the packhouse.

Potatoes from the conventionally cultivated area carried nearly twice the dirt to the packhouse as those from the controlled traffic rows.

The Wilcox team extended the axle on the harvester so it could run in the traffic row. It means less compaction in the paddock and less time and fuel used for remedial cultivation.

Reducing soil on harvested crop was a major reason to pursue controlled traffic, particularly in Pukekawa where harvest operations are often difficult. “The clay soil has amazing stickability,” says Simon Wilcox. “It gums up the harvesters, slows down operations, and then after trucking it to the packhouse, we have to take it away again.”

To monitor savings, twelve tonne lots of potatoes were harvested from each of the controlled traffic and conventional cultivation areas and tracked through the packhouse.  The washing plant crew reported big efficiency gains, with potatoes from the conventional area often needing a double wash, against the controlled traffic area needing only one.

When the trial was harvested, weather and soil conditions were dry.  “We needed rain to see the full effect of controlled traffic on harvest conditions,” Simon Wilcox said.  “For once the rain never came! But we saw enough to know that controlling traffic is a good thing for our business, from paddock to packhouse”.

In addition to the harvest cost savings and soil improvements, the Wilcox team estimates they halved fuel use through controlling traffic. Convinced of the benefits, they have increased their controlled traffic area to 44 ha this year.  “It’s about making things better today and for the future,” says Simon.

The trial at A S Wilcox is part of the LandWISE ‘Advanced Farming Systems’ project run in conjunction with the Foundation for Arable Research.  It has close links to ‘Holding it Together’, a project with Horticulture New Zealand.  For more details, contact James Powrie (LandWISE) or Paul Johnstone (Plant and Food Research).

As published in Grower July 2010.

About 12 months ago A. S. Wilcox embarked on a new challenge – to adapt controlled traffic farming (CTF) to their Pukekohe-based cropping operation. A. S. Wilcox is pursuing CTF in order to improve soil quality and overall productivity. They also hope to lower fuel use.

With support from Land WISE and Plant and Food Research, a seven hectare site was allocated to the first year trial; half is being managed according to a CTF approach they have designed, the other half to their conventional “random traffic” practice.

The key is keeping all traffic on the same wheel tracks, never driving on the productive ‘garden’ areas. Under CTF, vehicle traffic is restricted to permanent wheel tracks. These solid ‘roadways’ are better able to carry traffic, allow access sooner after rain and reduce rolling resistance energy demand. The wheel tracks are not removed at the end of a crop, they are retained to carry future traffic. As a result, there is no need for the deep ripping and powered cultivation that is often required to remove compaction caused by random traffic during the season and at harvest.

In this article, crop supply manager Simon Wilcox and scientist Paul Johnstone provide a brief summary of this operation and promising soil indicators measured during the first year.

The trial site is on clay loam at A. S. Wilcox’s property in Pukekawa. The site has been intensively cropped for almost 15 years, typically to their standard 3 year rotation of onions, potatoes and oats. Heavy cultivation has been required to remove compaction and prepare beds for successive crops. Harvesting operations are often difficult in these soils, especially during wet conditions.

There were two key differences in how each half was managed in the first year of the trial. The controlled and random traffic areas both received the same primary cultivation. But there were some differences in the way the onion beds were initially formed (??) and the way the crop was subsequently harvested. In the controlled traffic area, all harvest equipment remained in wheel tracks, whereas in the conventional random traffic area, equipment also travelled on bed tops.

What has been learnt so far?

There was no difference in onion yields achieved using either approach. In time A.S. Wilcox hope the controlled traffic approach will deliver a deeper, better-structured soil that can either support larger crops or require fewer fertiliser or irrigation inputs.

Soil quality of prime interest, so a range of soil physical properties were assessed immediately prior to the harvest of onions in January. These included bulk density, aggregate size and also aggregate stability. There were few big differences in these indicators at this stage, probably because both areas had received the same primary cultivations and all seasonal traffic for weed, pest and disease control was in the formed wheel tracks.

Water infiltration under controlled traffic did however increase by about 30%, an encouraging observation which appeared linked to differences in bed forming practice. This was consistent with visual observations made during the season by the Wilcox team, where the effective soil depth was much greater under controlled traffic.

The most recent set of soil samples were collected in April, just prior to the planting of potatoes. The effects of the different traffic approaches at harvest appear to be emerging. Under the conventional random traffic practice there were a greater number of big, clumpy aggregates – a sign of residual compaction. By contrast, smaller aggregates were formed with less cultivation under controlled traffic.

The current potato crop will give the best indication yet of the potential benefits of the new controlled traffic approach. If these soils are better drained and structured, we expect to see more favourable lifting conditions during the challenging winter period.

In addition to the emerging soil benefits, the Wilcox team estimates they can reduce fuel use by about 50% by managing their traffic. The hoped for energy savings appear to be real. Convinced of these benefits, A. S. Wilcox has increased their controlled traffic area, implementing it on 44 ha this year.

All and all, early observations are encouraging for successful controlled traffic farming at this site!

For more details on these results contact James Powrie (LandWISE) or Paul Johnstone (Plant and Food Research). Funding for this project has come from the Sustainable Farming Fund ‘Advanced Farming Systems’ and ‘Holding it Together’ programs.

The LandWISE website www.landwise.org.nz contains information on current members, articles on precision agriculture and many resources and tools.  It is also a place to comment, chat and ask questions about where to go to learn more.

LandWISE membership puts you in touch with other innovative growers, industry folks and technologists, join at http://www.landwise.org.nz/join/

Visit the website to learn more, or contact James direct on 06 6504531 or 0272 757757.

As Published in ‘Grower’ Magazine May 2010.

James Powrie and Dan Bloomer, LandWISE Inc.

“I don’t care what it cost! He’s not such a grumpy b*&&er when he comes in off the tractor.” So said the farmer’s wife.  The interviewer had asked, “What rate of return are you getting on your investment in GPS guidance?”

Our experience is that many farmers respond in non-financial terms, preferring instead to explain why they “would never go back!” They are able to work longer and feel better at the end of each day, and they know they do better jobs than they can without it. What value should you put on a fresher mind, less silly mistakes, ability to work longer hours during high pressure periods?

There’s a story of a contractor entering the busiest part of the planting season. He lost his night shift driver and ending up planting for 100 hours at a stretch.  “I don’t recommend it but there’s no way it would have happened without GPS. 24 hours would have cooked me,” he said.

Most farmers adopt GPS because it saves on “soil, oil and toil”. And it is true that precision agriculture tools such as tractor guidance can reduce costs in the paddock; saving time, fuel and agrichemicals too.  But a message we keep hearing, is that the in the cab benefits were under-estimated, and a key reason to add more GPS units on other tractors.

It’s about Ergonomics – the study of the ‘fit’ between people and their tools and environments.  It is one of the things that owners and operators of self steering tractors love.   The bottom line is that GPS makes things more comfortable for the operator, and leaves them free to concentrate on the actual task being done.  Less stress in the cab equals less fatigue, because driving straight is handled by the gear.  This allows drivers to monitor the implement, the job it is doing and any adjustments required.

“The important work happens behind the tractor. That is where the money is made and lost,” says John Evans who grows process peas, specialist seed and a range of arable crops in Canterbury.  “Steering depends on looking out the front, but you can’t look out front and back at the same time. After trying GPS you realise how you can’t do the job as well without it,” he says.  “And my ‘cell phone wiggle’ is gone; when I answer the phone, the tractor stays on its bullet straight path.

Donovan Keen was furrow dyking a carrot crop at Lawson’s Organic farms when James caught up with him.  They watched the implement for five minutes without having to look out the front of the tractor.  “Especially with precision weeding; without GPS, one look back and we take the crop out,” said Donovan.

It is not just the owner-drivers that benefit. As employers, farmers are noting additional benefits. Randal Hanrahan grows process sweetcorn, potatoes and arable crops, farms livestock and operates an Agricultural contracting business in Ashburton.  With a larger operation to manage, Randal found driver training and hiring to be a major headache.  “Everything is so much easier with GPS,” he says.  “Driving very straight is a skill that is not often found.  This technology allows even a new driver to steer straighter than an old hand – every time” says Randal.

Because the tractor is steered by GPS the real work can be monitored and the office work can happen in the cab too.  Randal takes his phone and laptop up the ladder and runs his contracting business from the cab.  “It saves me time at night”, he says. “When I get inside, I can spend time with my family.”

The LandWISE website www.landwise.org.nz contains information on current members, articles on precision agriculture and many resources and tools.  It is also a place to comment, chat and ask questions about where to go to learn more.

LandWISE membership puts you in touch with other innovative growers, industry folks and technologists, join at http://www.landwise.org.nz/join/

Visit the website to learn more, or contact James direct on 06 6504531 or 0272 757757.