"Growers have been using floating systems for years, but not always in the right way. We verified that an essential element is the temperature of water." Speaking is Gian Paolo Menarello with Idromeccanica Lucchini. The company set up a testing area in a company located in northern Italy to grow lettuce using a floating system in winter. "They proved that it is not so much air temperature, but rather the water temperature that determines crop development."
Idromeccanica Lucchini is continuously experimenting with hydroponic cultivation and, specifically, with floating systems.
Tests are still being carried out in a non-heated greenhouse (45 meters long, 8 meters wide and 3.5 meters high) protected with a plastic film. A heat exchanger helps maintain the temperature within a suitable range without wasting too much energy, so that the crop can be economically viable.
"Another fundamental aspect is the monitoring of oxygenation. While the floating system technique helps make a better use of the space, it cannot be improvised and all materials must be chosen accurately. For example, supports are made of PVC suitable for young plants."
Lucchini focuses on innovation working alongside entrepreneurs to make sure all steps are verified and all components are checked. For example, while the temperature in tanks must be regulated in winter to obtain sustainable productivity, the environment needs to be cooled down in summer.
"The first winter harvest was excellent and economic results were very positive for growers. Heads were large, weighing around 450 grams each. Thanks to our tests, we proved that, in theory, lettuce could be cultivated throughout the year in northern Italy too, but the cycle becomes too long in central winter months, so it is not worthwhile. Anyway we are also carrying out tests with parsley, celery and endive."
This type of cultivation leads to many advantages: there are no soil fatigue problems, a lot of water can be saved and there is no need to weed or prepare the soil. In addition, producers can make more precise plans and spend less money on labor.