Yesterday, a group of international greenhouse consultants that are active in today's upcoming markets of worldwide greenhouse horticulture where invited by fertilizer manufacturer Haifa to join their "Pioneering Knowledge" spring fertigation seminair. Because the seminars were organized in co-operation with Wageningen UR greenhouse Horticulture, the group was also invited to join a tour around the Bleiswijk research campus. The algae cultivation trial inside one of WUR's 78 greenhouse compartments got a lot of interest and questions from the group.
Below you will find a small photo report Hortidaily.com made during the visit to the site. A complete report on the seminars will be published later this week on our website and newsletter.
Wim Voogt from Wageningen UR gave a brief introduction on the trial. Inside the trial setting there are 'artificial algae rivers'
The algae flow counter clockwise, starting below. Besides water pumps, their is also an an additional air pump connected in the circulation. The algae are being fertilized with air that is very rich in carbon dioxide. The algae need a lot of carbon dioxide to stimulate growth, just like a common greenhouse crop.
The microalgae are commercially marketed as food for farmed fish. These fish and the produced fish oil is well known for its omega-3 fatty acid content, the farmed fish don't actually produce omega-3s, instead accumulating their omega-3 reserves by consuming microalgae.
The algae prefer a temperature of 35 degree Celsius. This could also make it attractive for greenhouse growers to combine the cultivation with common greenhouse crops, however both crops need a certain amount of light. This is a challenge at the moment, but researchers are in search of a solution for this.
The algae are being collected in the filter at the end of the circulation. The next step is the processing of the harvest; a very intensive costly operation that involves freeze-drying and centrifugation. This part of the whole process generates a high cost price, there for the produced algae at WUR disappear in the sink, for now.
Another problem is that the algae crop is very sensitive to stress situations due to climate and nutrition conditions. This results in the deposition of algae on the inside of the tube. Therefore the system has to run special cleaning programs, which also makes the cultivation time intensive.