With the future regulations and the obligation to treat discharged water, making optimal use of raw materials is becoming an increasingly important issue for Dutch growers. The breeding and propagating company Beekenkamp Plants has therefore optimised the design of its new site to make it ready for the future.

Water flows through the 6 hectare greenhouse from the 550 m3 silos at a rate of 200 m3 per hour. The room in the new building in the Dutch village ‘s-Gravenzande which houses the silos and the seven liquid fertiliser mixing tanks looks empty and big. “It’s actually an enhanced version of the installation we have at our new site in Maasdijk. For example, we have installed valve position reporting to improve safety and reliability in the fertilising system,” says Erik Heijs, fruit crop coordinator at Beekenkamp Plants. “Because we have a lot of different crops and a lot of different customers, we have opted for a lot of different mixing tanks. This gives us the leeway to make adjustments and respond to our customers’ needs.”
The propagator uses the ‘Van Iperen Vloeibaar system’, a package of single liquid fertilisers. With the calculation program that comes with it, he can calculate the nutritional requirements of each crop type and the right fertiliser recipe is assembled automatically. “We still work with solid fertilisers at our older site in Maasdijk, but they are quite a hassle. It’s heavy work and it’s difficult to mix the fertilisers properly. We have been working with liquid fertilisers at our new site for six years now and we are very happy with them. The biggest benefit is the convenience: the system is fully automatic, the fertilisers are easy to mix and the quality is reliable.”

Level measurement

On the filling tanks along the wall in the open room, there is a sensor which uses sound to measure the amount of liquid fertiliser in the tank. This level measurement system automatically generates an order when supplies fall below the minimum level. “Then we top up the tanks in good time,” Eric Watzeels of Van Iperen explains. “So the growers don’t need to keep an eye on levels themselves. We do it for them.”
But that doesn’t mean that the growers can sit back and do nothing. “We have to keep an eye on what the plant consumes and keep on doing analyses,” says Heijs. “Are the recirculation plans still right? We have plenty of experience, of course, but we pay extra attention with a new greenhouse. To measure is to know.”

Cleaner space

Watzeels has seen a steady rise in demand for liquid fertilisers in recent years. “It is not only the convenience that growers like, but it is also increasingly about sodium. That is a major issue. Liquid fertilisers contain far less sodium than solid ones. The cleaner it is at the front, the easier it is at the back, I always say. We make sure our customers really can choose low-sodium fertilisers. We select our suppliers on that basis.”
Liquid fertilisers also help keep the workspace cleaner, he says, pointing to the room at the propagation nursery. “There are no empty bags or other rubbish lying around. It looks neat and tidy and makes for a more pleasant working environment. That’s also important.”

Quality assurance system

This company’s new site in ‘s-Gravenzande has been operational since the end of October 2016. Thousands of sweet pepper plants are already in the greenhouse and staff are busy potting up the newly arrived tomato plants. Access control and nursery hygiene are also strictly organised, with hygiene barriers and compulsory changing before you enter the production areas, forming part of the GSPP quality assurance system which the production sites comply with.
This new site adds six hectares of glass to the breeder’s three 20-hectare sites in Maasdijk and four hectares in Lutjebroek. There is room for another three hectares. “We have the luxury of being able to grow every year,” says Heijs. “The growers are getting bigger and we’re growing with them.”
The breeder of young ornamental, foliage and vegetable plants manages to fill its space all year round. The crop coordinator: “That’s mainly due to the developments in the market. The artificially lit tomato greenhouses are driving expansion. Cucumber growers are now growing three to four crops a year. That’s very good for our workload. These developments are making it necessary for us to upscale. We used to use third party growers, but we’re starting to do more in-house so that we can be confident of the quality.”

100% recirculation

The new building is an example of the quality the company wants to deliver. “We have optimised the design of the greenhouse. We can steer very precisely with water and nutrition.”
The water coming back from the greenhouse is collected separately per recipe in a return silo and treated with UV light and hydrogen peroxide. This approach completely kills all pathogens and enables the company to recirculate 100% of its water. They can re-use any fertilisers the plant doesn’t use. For many years the propagator has also been working with the Vitaliser, a water treatment system based on the physical principle of molecular vibration.
Thanks to the water technologies they have chosen, the company can recirculate the maximum amount, and if they should need to discharge any into the sewers, they can continue to do so after 2018 because they use an Opticlear Diamond filter which filters out more than 95% of the crop protection chemicals from the water. “We are ready for future regulations.”
But this level of control not only comes from the law. Society and customers also make demands. Heijs: “Some customers want us to deliver plants containing no chemicals at all and demand zero tolerance. This is another reason why we need to put extra measures in place.”

Investment a tricky issue

Although closed growing is good for the environment and the company is now geared up for future regulations, investment is a tricky issue. “We can do this because we are a big company,” Heijs admits. “We save money by recycling, but that does mean you first have to invest in good equipment and raw materials. That would certainly be difficult for smaller companies.”
Watzeels comments: “The legislation is going too fast and is being rushed through. Growers must have already bought the equipment or set up a joint plan with other growers this year in order to comply with the future regulations. That’s not enough time. We don’t even know which equipment works best. The Opticlear has only recently been approved by the authorities. So small nurseries are really having problems with this.”
Heijs is now also looking at other sites in Maasdijk. “There are still some things we need to optimise. For example, we are not yet working with a purification plant at all our sites. But the financial aspect is a consideration for us as well.”


In order to meet the ever more stringent regulations and specific customer demands, it is becoming increasingly important for growers and breeders to optimise their use of raw materials. Propagator Beekenkamp Plants is using new techniques at its new ‘s-Gravenzande site. They enable the company to maximise recirculation and discharge into the sewers if necessary because they are using an approved purification system. This investment is a tricky issue for smaller horticultural businesses.

Text and images: Marjolein van Woerkom.