Norway: Copper fertilization saves business of year round lettuce grower

Hans Kristian Berge is producing salad for restaurants and shops in Norway. The nursery covers 3000 square meters, and is equipped with lighting and heating for year round production of the two varieties Crispi and Rapid. The plants are sown in-house in 5 cm pots with peat moss. After the initial sprouting they are placed in single row hollow trays, where the water passes in the bottom. The distance between the trays is increased in six steps as they move to harvesting. System from Viemose & Driboga.

Hans Kristian Berge in his greenhouse

Pythium fungus attacks developed so strongly in 2008 that the production was seriously threathened. The roots only growed a couple of centimers out of the pots. The turnover dropped by 75%, and the economy of the nursery was in danger of collapsing. Hans Kristian Berge then installed a UV light system and a steam washing machine for the trays. This helped somewhat, but the production remained far too low. Something had to be done. An Aqua-Hort machine was installed by help of Per Donbæk from the G3 Company. Hans Kristian describes it as “switching on the light”. In a couple of days the roots started to develop into full size. Production went up to normal levels.

The outcome of the Aqua-Hort installation was that production went up to normal levels again, and the economy of the nursery was secured. The water is recirculated constantly with about 5 cubic meter per hour. A level of 0,8 ppm free copper is maintained in the nutrition water. This level can be achieved by dosing 0,4 ppm to the water passing out to the plants. Supervision is very easy. The roots tell if the machine must be adjusted. Plant tissue analyses shows that the copper levels are 21 and 14 ppm TS respectively, which are normal levels for a salad crop.

For more information:
Aqua Hort
Aksel de Lasson
Tell: +45 702 26 611
aksel@aqua-hort.dk
www.aqua-hort.dk