Per square metre, not per hectare

The unit tells you everything

Field farming counts tonnes per hectare. Greenhouses count kilos per square metre.

That is not a technicality. A greenhouse costs money per square metre to build and per square metre to heat, so it has to earn on the same basis. It is why the Dutch never chased size. They chased intensity.

Cultivar decides more than technology does

On tomato, published yields run from about 28 kilos per square metre for cherry types to around 90 for beef.

That is a threefold spread, and it is settled before anyone specifies a single system.

Worth knowing before you chase the top of that range: once you count the labour, the bottom line across types often lands in the same place. The heaviest cropper is not automatically the one that pays.

What the greenhouse actually contributes is light

Inside the range a crop can use, one percent more light is about one percent more yield.

That one rule explains most of the design. It is why the roof puts as little steel as possible over the crop. Why the covering is specified to the decimal. Why lamps get sized against the daylight a site is actually short of, month by month.

Carbon dioxide at around 800 ppm, a stable climate and a controlled root zone then decide how much of that light the crop can turn into fruit.

The part you cannot buy back

Climate strategy, feeding, enrichment — all of it can be improved in a greenhouse that already stands.

Light cannot. Transmission is fixed the day the structure is designed, and no equipment installed later gives back daylight the building threw away.

So the yield conversation happens before the steel is ordered, not after.

DutchGreenhouses® sizes the structure, climate, water and light against a yield target for a named cultivar — so the number in your business case is one the building can actually reach. Get in touch with your crop and your market, and we will model it.

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