"Deep Flow Technology is nowadays a serious and sustainable alternative to the growth of leafy vegetables in the open ground." That is stated by Andre van der Stoel, owner of Industrial Product Solutions BV (IPS). IPS develops and produces (automated) DFT systems.
The principal of DFT (growing leafy vegetables on floats in an industrial pond) is already known for several years. However, for a long time this growth method was something for pioneers. It turned out to be difficult to be successful on the large scale.
"The growth of the vegetables lagged behind. There has been a lot done related to automating these systems, for example on transporting the floats. But when the crop does not grow properly, automation does not make sense yet. At IPS we decided to approach it differently: first, we need to make sure that the crop will grow, only after that automation gets relevant."
Creating the right circumstances for growth
The philosophy of IPS focuses first of all on the plants’ welfare. The company profiles itself by an integral approach, in which it has knowledge on and controls all the aspects of growing on DFT systems.
"During development of our DFT system, plant growth has been tested and evaluated thoroughly. We’ve done a lot of research and several experiments on creating the right growing circumstances. Only when that worked out, we started to work on automation. The end result of our research-based approach is an efficiently automated system which can grow high-quality crops", says Van der Stoel.
"In this way, growing on water is a real improvement compared to conventional growing methods. Disease pressure in the DFT systems is very low, hardly any pesticides are required. Next to that, there is no need for crop rotations to maintain the soil quality and no nutrient leaching happens. Finally, the production stays constant throughout the year. The interest is large: in the Netherlands supermarkets such as Jumbo and Plus and in Germany the famous brand of Bonduelle are regular buyers of lettuce grown on systems of IPS. Several DFT systems are installed in China and even growers from North America and Australia show serious interest."
A unique element in the DFT system of IPS is the use of a special, patented, oxygen injection unit, that increases the level of dissolved oxygen in the water.
"Experience made clear that this oxygen unit is of crucial importance for the performance of the plants in our system. Dissolved oxygen levels is a highly underestimated factor in plant growth. It is necessary for various growth processes, such as the uptake of nutrients as nitrogen, phosphate and potassium from the water, but also for the formation of proteins and the production of dry matter. Oxygen deficits in the water cause therefore growing problems. Although access to oxygen is important for every crop in every growing system, in a DFT system the relevance of oxygen is even higher, as all oxygen consumed by the plant needs to come from the water in the pond."
Usually, diffusion between air and water functions as a natural way of adding oxygen to the water. "However, because the ponds are fully filled with floats there is hardly any contact area between water and air and no diffusion takes place. Our patented oxygen unit can easily increase dissolved oxygen levels up to the maximum oxygen holding capacity of the water, without consuming a lot of energy", explains Van der Stoel. Besides their oxygen unit, IPS also supplies all other equipment needed for the water management.
To position the plants in the water, IPS designed a completely new, patented float. IPS was the first company worldwide to choose for the use of whole blown polyethylene, a material that can be cleaned very well, instead of the vulnerable polystyrene. The use of polyethylene reduces the chance of plant diseases and bacterial infections. Moreover, this kind of float will last a long time, being usable several years. The numbers of plants can be adjusted per float type, so the density of the crop is variable. It is even possible to work with a two-phase growing system, in which in the first phase the plants can grow in a more dense float and further in the growing phase on floats with more space. The floats can be carried out for pressed clods, plugs (e.g. growcoon), pots and many other substrate types.
"Efficiently using a large DFT system asks for ways of automation. Manual processing all the floats in and out the water is costly and time-consuming", says Andre. In the DFT system of IPS, almost everything can be automated. A special float crane in combination with a winch system in the pond is available to transport the floats into and out of the water. The floats can be cleaned automatically in a special washing machine. In addition, IPS offers a transplant robot to automatically transplant in a two-phase system.
"The process of harvesting can for a great extent be automated as well, among other things with a system which shears the roots from under the float and a system which disposes the harvest waste. The level of automation depends on the requirements of the customer. The system of IPS is made up of several automation modules. This makes it possible to design every new project in a unique composition."
See also the following article: - about the relevance of IPS’s oxygen injection unit in creating the right growing circumstances.
Industrial Product Solutions will be at GreenTech in stand 11.512.