Since a few months, Theo, Ben, Thomas and Mariëlle Akerboom have been growing the freesias in one of their three locations in gutters. ‘Freesia cultivation 2.0’ is expected to offer many advantages: optimisation of cultivation conditions, complete recycling and eventually, a cultivation without fossil fuels. Theo Akerboom: “It’s a complete system and that is exactly what’s so good about it.”
By Arie-Frans Middelburg
“If we continue growing our freesias the traditional way, in soil, we won’t last for another 25 years”, says Theo Akerboom. Theo, his children Mariëlle and Thomas and his nephew Ben Akerboom would be facing too many challenges with regards to labour, energy costs and the legal requirements around the discharge of drainage and minerals. To ensure the continuity of the business, Akerboom Freesia started testing cultivation in gutters. After several rounds of tests, their greenhouse in Nieuwe Wetering was fitted with 5,000 m2 of gutters last April. The first experiences are positive and they’re planning to switch to freesia cultivation in gutters lined with coconut fibre for the entire greenhouse – almost 2 ha – soon.
Improved root environment
“The roots of these plants are amazing”, says Theo Akerboom when he describes one of the advantages of cultivation in gutters with coconut fibre. “The improved root environment means that plants can make optimal use of water and nutrition, leading to stronger and better quality plants.” Cultivation in gutters is easier to regulate, too. “We can observe patterns. What does the plant absorb? What does it need and what not? We can register exactly how much water and nutrition the plants soak up and when. We’ve learned more about watering and fertilisation during the last couple of months than during the entire thirty years before”, says Theo Akerboom adamantly. They’re aiming for a 20% increase in harvested kilograms, distributed over a 10% increase in number of stems and a 10% increase in weight per stem.
Theo Akerboom had already been convinced for a while that cultivation in gutters was technically feasible. It was based on research regarding the cultivation of other crops on coconut fibre. “Temperature was the most uncertain factor for us. If we weren’t able to regulate the temperature in the gutters, we wouldn’t be able to continue.”
Some of the initial tests with steel gutters showed that the temperatures were too high. Theo: “That’s when we switched to aluminium gutters. Aluminium is a good conductor.” Eventually, the plastic gutters in Akerboom’s greenhouse were equipped with an aluminium strip. The cold temperatures of the cooling hoses underneath the gutters are distributed by the aluminium strip. We can regulate the temperature per section. During the first round of freesia cultivation in gutters, they had to deal with a particularly warm May and June, but the desired average temperature for a 24-hour period was achieved without any problems.
No more steaming
In addition to the optimisation of the cultivation, there’s the savings on steaming costs. Ben Akerboom still spends around 11m3 of gas per year for each square metre of his nursery in Nieuwe Wetering, on steaming. Growing in gutters puts an end to these costs. Furthermore, the moisture that gets trapped in the soil because of the steaming no longer needs to be evaporated, which means a further reduction in heating costs. On the other hand, there are costs associated with coconut fibre, too.
“No steaming means a different way of working”, says Theo. Akerboom Freesia doesn’t have to deal with this heavy task anymore. And they no longer need to worry about digging and preparing the soil or applying fertiliser either. The freesias are planted in a different way. It’s partially done mechanically. A machine puts down a layer of coconut fibre in the gutters. After that, the bulbs are planted manually, and then they’re covered with coconut fibre, which is applied and flattened by a machine again.
But there are more savings, for example on Styromull, which they don’t need as much of. Theo: “We still use Biofoam, but only a third of the volume that we use for growing on soil. In addition, the increased efficiency means that we use less fertiliser and less water. There’s no waste.” Theo points out that coconut fibre can hold large quantities of water, so dehydration isn’t an issue.
The fact that Akerboom Freesia’s new system includes full recycling, means that they will also completely adhere to the latest legal requirements. From the 1st of January 2018, growers will no longer be allowed to discharge drainage via sewers or surface water and from 2023 they’ll no longer be allowed to discharge minerals via surface water.
Freesias without gas
An important part of the whole idea of growing in gutters was the aspect of energy. The enormous savings on energy costs was a reason for the Ministry of Economic Affairs to approve an MEI (Market introduction energy innovation) grant. In addition to the savings on steaming costs, Akerboom expects to be able to save on gas consumption for greenhouse heating, too. “In ten years time, we’re hoping to grow freesias without using any gas at all”, says Theo. At the moment they’re still using around 8-10m3 per year for each square metre of Ben’s greenhouse.
Akerboom hopes that in the near future a combination of heat pump, heat from the cooling system and air handling units, will be sufficient for all their energy needs. The heat from the cooling system can be harvested during the day and can be used at night to heat the greenhouse and/or heat the gutters. Air handling units (AHU’s) bring outdoor air into the greenhouse for dehumidification of the greenhouse air and for CO2. There’s enough space to accommodate the hoses of the air handling system. They can be placed in between the gutters. One freesia bed is 1.20m wide and consists of four gutters, spaced 15cm apart.
Coconut fibre ‘sausages’
One of the concerns the Akerbooms had beforehand regarded the harvesting of the bulbs. Would they get stuck in the coconut fibre? Would they still be usable? Last summer, the bulbs were harvested manually and that went well. Ben Akerboom reckons it took a little longer than with the traditional cultivation method. He would like to raise the coconut ‘sausages’ filled with bulbs, so that the pickers can stand up straight when they’re removing the bulbs from the coconut fibre. An additional advantage is that that would allow the ‘sausages’ to be removed by conveyor belt and perhaps used elsewhere as a substrate. The quality of the bulbs that were harvested from the gutters was excellent.
Akerboom Freesia’s cultivation system was developed in-house and is patent pending. The system was designed jointly with consultancy firm Stockmann.Nu from Roelofarendsveen, who also assisted with all the legal requirements. The company is hoping to switch entirely to the new cultivation system within the next five years. Akerboom thinks that the system would also suit other types of crops.
