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).