Passion for perfection
Family business Schenkeveld was founded in 1937 and has been solely growing vine tomatoes since 2002. Nowadays these tomatoes are grown on 5 locations. The newest of these locations is Schenkeveld Schiphol, an expansion project that was started in 2016. The complete project consists of four greenhouses of 11 hectares each. In 2017 and 2018 the first two greenhouses were built and are now in production. The other two greenhouses will be built in 2020 and 2021.
Cultivation manager Arthur van der Meijs has been involved in this project from the very first moment and is responsible for cultivation and crop protection. With this the product always comes first, which is evident from the Schenkeveld slogan ‘Passion for perfection’. Arthur says: “We do not want to be the biggest, but we do want to be the best”. The ambition for the future is to make the Schiphol location a success, together with all employees. “We strive to ensure that organizationally everything runs smoothly, so everyone enjoys working at Schenkeveld.”
Next to a good organization, a good crop is indispensable for a successful greenhouse location. An important condition for a good crop is a good irrigation strategy. For irrigation control Schenkeveld uses water content sensors and the Hoogendoorn Aquabalance. “In fall and winter we irrigate based on interval and delay time, but I do check Aquabalance daily for the insights it provides in for example irrigation, slab weight, dehydration, and EC and pH content of the drain”. These insights provide information about the crop activity and the condition of the substrate, enabling early signaling of deviations.
In summer, irrigation at Schenkeveld is controlled based on the Aquabalance system. According to Arthur the big advantage of Aquabalance is particularly evident on hot days with little sunshine. “On these days there is little solar radiation, but a lot of evaporation. Based on the solar radiation you would not irrigate. However, because the slab weight is decreasing, Aquabalance ensures that plants do receive water.” This results in optimum irrigation, completely aligned to the plants’ needs.
In combination with the irrigation software in the iSii process computer, the current weight and the saturation weight of the substrate are repeatedly measured and calculated. Based on the course of these values Aquabalance determines the right time for the next drip cycle. This way plants never receive too much or too little water and irrigation is optimized. In addition, Aquablance generates data that leads to meaningful insights, which can be used to optimize the irrigation process.
Next to Aquabalance other sensors are used as well in the high-tech greenhouses at Schiphol. “We use a pyrgeo meter and plant temperature sensor to monitor heat emission and plant temperature.”
When heat emission is high, the crop temperature can be lower than the greenhouse temperature, which can lead to unoptimized crop growth. The measurements of the pyrgeo meter can also be used by the iSii process computer to adjust the screen control based on the level of emission. This prevents cooling of the crop and can save energy.
“We also use the plant temperature sensor as a factor in determining the VPD (Vapor Pressure Deficit), which indicates whether the plant is in stress or in balance”. Based on the VPD value the iSii process computer can optimize the climate controls and irrigation controls, and avoid crop condensation.
However, according to Arthur, sensors and data are not enough to come to a successful crop. “Generating data with sensors is important, but you also need knowledge yourself. You have to understand what to do with the data, because data cannot tell you everything”.