The Cultilene Smart Root Zone Management framework is designed to help growers get the best out of their Cultilene substrates. In the framework we look at each component of the substrate system with the aim of structuring and optimising the layout and use of the substrates. To ensure a perfect start to the growing season, it’s important to think about the following elements:

Optimising the substrate layout 
A successful growing season starts with an optimal substrate layout. For tomatoes, for example, it’s important to design the layout to optimise volume, spacing, plant density and additional heads. Cultilene provides support for this with our slab calculator, an online tool that quickly and easily provides growers with information on the correct substrate and plant density. Growers simply input basic details such as bay width, row or gutter length and the number of substrate rows per bay. Our specialists can help you maximise the benefits of Cultilene stone wool substrate. For more information please click here.

Calculating the dose size 
Using the correct DSF (dose size factor) is essential to avoid competition among roots. If the dose size is too large, roots are forced downwards, resulting in a smaller root cone. Because roots prefer less saline water, they tend to remain in the smaller cone, leading to overcrowding and competition for fertiliser and oxygen. This can also result in a loss of control, and dryback and flushing become less effective.

Based on the slab layout, we can calculate the dose size range. Our dose size calculator calculates the optimum dose size range to match the volume, allowing growers to adjust their stone wool substrate to the target levels for achieving plant balance. The dose size significantly impacts water content, the root cone and the homogeneity of the slab. 

Optimising drain slits and holes
Drain holes are crucial for maintaining the optimal water content and EC level. But they also keep the other parameters like oxygen, pH, temperature and microbiological life in the optimal proportions. By following the Cultilene drain hole philosophy, you can effectively control the substrate to achieve the best conditions, get the most out of the root zone and avoid competition between the roots. 

Without a sufficient number of drain holes, excess water and nutrients can’t easily exit the substrate. This makes the substrate wetter and leads to uneven fertiliser and trace element availability. Due to the higher water content, available oxygen can also be an issue. With the right number of drain holes, it’s easier to achieve even dryback and optimal water and fertiliser replenishment. In a uniform substrate, the roots have no preferred spot, so they spread out evenly and fully utilise the available volume. Plant balance can therefore be achieved by having the right conditions in the substrate. This leads to better water use efficiency (WUE) and fertiliser use, while also making it harder for diseases to take hold.

Drain slits should be made within 24 hours of planting, to allow any excess water to drain freely from the slab. The best position for these slits is between the plants and at the lowest points of the slab. Drain slits should be made vertically, at least 2 cm long, by cutting the foil from the bottom of the slab upwards. To minimise variation, it’s important to ensure that the drainage pattern for every dripper is the same. This reduces the standard deviation in the root environment, which can have a positive impact on production and quality throughout the greenhouse. 

Season Dynamics: setting your target levels 
Understanding the various crop stages throughout the season is crucial. Each part of the growing season has its own characteristics, which will influence the watering strategy and target water content and EC levels you use to achieve the desired plant balance. These may vary for every crop and grower. Define these stages clearly and establish boundaries for transitioning to the next phase. Also make a record of your goal for each stage: are you aiming for vegetative or generative growth, or perhaps you want a ‘recovery’ period? Be clear about your objectives.

Next, identify the target figures you are aiming for. This could be a single figure, such as the dryback at the start of the crop, or the limits you want to keep to. By doing this, you can adhere to the plan you made before the season started. repare your target list with all the historical data and your own practical knowledge. Your plan will be made with a certain idea in mind. If you find you are outside a target value during a particular phase, ask yourself why. A slight difference could mean that you have had to adjust to circumstances, but if there is a substantial difference, there must be a solid reason for that. Also try to keep the figures stable throughout all of the phases. 

When transitioning to new target figures, make adjustments gradually. This is one of the advantages of having a strategy: avoiding sudden changes allows the plant to react more smoothly and keep its processes running.

With a seasonal plan, you avoid having to make ad hoc changes, making it easier to steer the plant and control the parameters. Ultimately this will result in a well-balanced plant and give you more overall control.