13 November 1998

Drip wars start in irrigation sector

By Charles Abel

DRIP irrigators apply water more uniformly, but not all systems are equal.

With up to a fifth of potato irrigation set to be drip within 10 years, the race is on to differentiate products.

Pressure compensation to ensure the same output from each dripper regardless of field slope is a key feature of Netafims new Ram Super-Light 16mm disposable tape from Revaho UK.

Meanwhile, Hydro PCND from Plastro offers the same accuracy, plus a no-drain mechanism. That prevents excess wetting of lower areas, which can occur when other systems drain after switch off.

No-drain also avoids clogged drippers when emptying systems suck water back into outlets, says Yehu Peleg, irrigation specialist for UK importer Plasson. Lateral pipe runs of up to 300m are possible on flat land, he claims.

Field trials at CWS Farmings Castle Howard unit in Yorkshire and Cambridge University failed to show a yield advantage this year. "But quality, uniformity and tuber shape have been better at both sites," he says.

Price for a typical 20-25ha (50-60 acres) system, including supply main, pumps, filters and fertigation system would be about £85,000. Once the head control is in place further laterals cost about £2500/ha (£1000/acre).

Superior results are also claimed for Revahos Netafim Superlight piping, which sells for £2500/ha (£1000/acre).

"Tape products may cost £200 a year, but they will not deliver with the accuracy of a pressure compensated line or cover the distance or cope with undulations," says Revahos Julian Gruzelier.

Tape products can deliver 10-15% flow variation over 150-200m. Superlight varies less than 2% up to 200m even over undulations, he says. Such accuracy is essential if the benefits of applying fertiliser through a drip line are to be realised, he adds.

A 16ha (40-acre) field trial of fertigation through Netafim Superlight on a Yorkshire farm growing for McCain showed the value of applying nutrient with the water throughout the season could be greater in a wet season.

"Traditional surface applications of fertiliser are far more vulnerable to leaching by heavy rain early in the season, compromising crop growth," notes Mr Gruzelier.

lDemand for more efficient water use could see drip systems account for 20% of all irrigation within 10 years, forecasts Nigel Palmer of Plastro agent Wright Rain. &#42

DRIPBENEFITS

&#8226 More even rate and less waste.

&#8226 Pressure compensation boosts uniformity of supply.

&#8226 No-drain cuts clogging.

&#8226 Fertigation helps during wet.