3 November 1995

Tare away is big aim of Dutch industry

TARE, not tonnage, was the preoccupation of the Dutch beet industry at last weeks harvester demonstration at Numansdorp, near Rotterdam.

But measurements at the event also revealed large variations in root losses. Interestingly, the UK goal of minimum root losses seemed to be at odds with the Dutch aim of low soil tare.

Unlike UK growers, most Dutch producers have sufficient beet to meet quota this autumn and are uninspired by a C quota price of £12.20/t. Speedy lifting with minimum tare is the priority.

Their tare fixation stems from hefty penalties imposed by the processors, which face high costs for soil disposal. Few landowners want factory waste for fear of introducing disease and pest problems – particularly rhizomania and nematodes.

Tare currently averages 18.3% in Holland, of which about 6% is typically unpenalised as top tare. The remainder is charged at a rate of £10/t, almost treble the 1970 level and leads to a £1.62/t cut in the beet price. That adds up to an average £90/ha cost to growers, explains Frans Tijink of the Dutch Institute of Sugar Beet Research.

Environmental legislation on soil disposal could add a further £28.45/t to processor costs, says Mr Tijink. An average haul of 47km to a factory adds to the argument for tare cuts.

Since haulage arrangements in Holland mean cleaner/loaders do not feature, attention has turned to removing more soil in the field.

The IRS aim is to cut tare by 80%. To encourage that it is investing in research and seeking tax incentives for contractors who use tare-cutting equipment.

Last autumn it challenged manufacturers to modify their machines and last weeks event saw nine suppliers set their machines to work alongside three prototypes from IRS. Over 2000 visitors attended.

Field results from working trials on the dry, medium clay soil the day before showed good control of soil tare, but big variations in field losses from the six-row tanker harvesters.

An Agrifac ZA 215 EH fitted with narrow, heavy-land shears gave the lowest root losses – leaving just 1.6t/ha in the ground and losing 0.5t/ha from the machine. But dirt tare was 4.7%.

By contrast, an IRS development machine left 2.9t/ha of beet in the ground and lost 2.1t/ha from the machine. However, it recorded the equal lowest soil tare of just 2.8%.

&#8226 Turn to p65 for details of the mechanisms used to to rid beet of dirt.

Clean beet (above) is the key issue in Holland, with brushes (below)and spiral rollers (bottom)deployed to strip away soil tare.