Greenbrothers eggplants:
Absolute Humidity is crucial part of the The New Cultivation
The New Cultivation (HNT) is now being successfully applied in a number of vegetable and ornamental crops. The supervisory committee Eggplant wanted to try this new method of cultivation, but had insufficient funds for a large-scale, collective test. The solution: a greenhouse by Greenbrothers was appointed as a test site. With some 3,500 m2, a second screen and an outer air box were placed. Another part serves as a reference greenhouse.
But Greenbrothers isn’t the only one starting with The New Cultivation. Four growers from the supervisory committee apply the knowledge, and with good results. In addition, the group of growers who contribute financially to the test (with a combined acreage of about 100 hectares) receive information about the trial. Participation in the trial is very instructive, says Groenewegen. "I was always allergic to the term The New Cultivation. But during the last six months, I really learned a lot."
Moisture control is crucial in HNT. Geelen: "Often a minimum pipe is used to dehumidify the greenhouse. But that only works if there is no crop in the greenhouse. Otherwise you only add to the humidity.”
Crucial in this context is the term Absolute Humidity, or the number of grams of water per m3 of air. You would expect that RV and Absolute Humidity have a direct relationship, but that's not entirely true. RV is about the amount of moisture that the air could contain. That amount is dependent on the temperature of the air. The hotter, the higher the capacity. The Absolute Humidity provides insight into the moisture level of the greenhouse: the relationship between supply and drainage of moisture.
Geelen: "Often you think humidity in the greenhouse is increasing, but if you look at LetsGrow.com, it’s actually less humid. The absolute humidity decreases while the RV is in fact increasing, caused by falling temperature. With this insight so you can add more screens than you initially thought."
Experiential learning
The HNT-trial with eggplants uses LetsGrow.com, allowing Geelen to handle moisture levels even better. "LetsGrow.com is a nice way of gaining experience. It works a lot better than, say, a course. I have been a user from the start, but the possibilities of LetsGrow.com continue to amaze me. Without LetsGrow.com I couldn’t do my work as well."
Substantial energy savings
The test with The New Cultivation is only about six months old, and lasts a total of three years. But for Frank Groenewegen, the test is already successful. "We have achieved considerable energy savings, because we clearly have more screen hours than last year. Sure, we have also been helped by the mild winter. But with what we have learned from The New Cultivation, we were able to achieve a substantial gain.”
More information:
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3131 HX Vlaardingen
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cpm@letsgrow.com
www.letsgrow.com