New technologies for cultivation in closed agricultural systems

Indoor farming has established itself as a visionary model in the transformation towards more sustainable agriculture. But modern and vertical greenhouses require systems that combine intelligent controls and sensors.

The new venue of the DLG (German Agricultural Society) will present a range of technologies for cultivation in closed agricultural systems that function in closed material cycles, detached from external environmental conditions.

Automation technology

Some are the size of a normal shipping container, but inside – thanks to state-of-the-art automation technology – mobile vertical farming solutions such as GreenBox or iFarm deliver fresh and locally grown salads, herbs or root vegetables all year round under all climatic conditions.

These kinds of solutions expand the possibilities of crop cultivation and can bring food production to densely populated urban areas. They can also do this with less water and fertiliser than conventional field cultivation.

Continuous monitoring and optimising

A successful example is Bustanica, the world’s largest vertical farm, located near Dubai on the Arabian Peninsula. This farm supplies about three tonnes of leafy vegetables per day to a catering company, serving more than 100 airlines. Plants are grown in several tiers on top of each other. To monitor growth holistically, many measurement variables are captured with powerful technology.

Indoor systems are able to provide a fully controllable environment unaffected by weather, where all desired climate conditions can be continuously monitored and optimised. In order for the closed cultivation systems to realise their full potential, they need automation systems that combine intelligent controls and sensors.

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Aeroponics and aquaculture

These technologies can be found in the Inhouse Farming – Feed & Food Show. With the theme of Controlled Environment Agriculture (CEA) – including vertical farms, container farms, aeroponics and aquaculture – the new DLG platform will combine all aspects of indoor farming and link these to the ideas of precision farming.

According to Marcus Vagt, DLG Division Manager Energy, Inhouse Farming and New Foods, the focus of interest is more and more on process control and data acquisition, which are becoming more complex in closed cultivation systems.

A variety of different sensors

A perfect example of this is hydroponic irrigation, which requires optimised nutrient management. Both overshooting and undershooting the optimum will lead to damage or crop failure. Modern control equipment and reliable irrigation solutions, however, ensure that the right amount of water and nutrients is used as effectively as possible at the right time.

A sophisticated mix of artificial intelligence (AI), smart sensor technology and innovative robotics will be presented on the trade fairgrounds, all technologies that enable the establishment of a comprehensive monitoring infrastructure.

The exhibiting technology providers help to develop the best automation strategy for a vertical farming project

A variety of different sensors can be used: Starting with flow meters for water and nutrient dosing, pressure sensors for the water level and conductivity probes for checking the concentration of minerals, to sensors for regulating the pressure of the pumps.

“The exhibiting technology providers help to develop the best automation strategy for a vertical farming project” Mr Vagt emphasises. “And to find the right technology for it.”

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IO-Link technology

Vertical farming in particular places high demands on automation, as the plants grow in multi-storey metal racks that often can be up to ten metres high. Each line has a large number of I/O (input/output) signals on the individual floors that must be routed to the control system.

Under these conditions, a conventional system design requires considerable programming and integration effort. But the connection of all measuring devices via IO-Link technology is more elegant. Such field modules reduce the complexity of process control, and also provide more data from each sensor, reducing the overall need for sensors.

Current technologies

The commissioning of the line from the physical wiring or wireless connection of the sensors to integration and programming, therefore becomes much more efficient. Operating companies have the option of linking water management, climate control and energy management of the greenhouse via a central process computer. The cultivation processes and systems can be scaled well and future projects can be implemented more easily.

Current technologies in supply chain automation also offer enormous flexibility

Current technologies in supply chain automation also offer enormous flexibility. Systems for handling goods or driverless transport can be optimally configured for the processes and premises of the vertical farming operation as well as for the type and cultivation of the plants. Shuttle systems can move shelving units with growing plates in such a way that the plants’ needs for water, nutrients and light are met around the clock.

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Process-related innovations

With OrbiPlant, the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME) has developed a vertical plant cultivation system that makes this possible on a large scale. A pilot facility in Aachen has a 24 square metre cultivation area.

OrbiPlant offers new process-related innovations. For example, an undulating conveyor belt system is used that fixes the plants in place and continuously realigns them in the room. The rotation forces the plants to constantly realign themselves in the earths gravitational field.

This effect triggers the production of plant hormones that stimulate cell growth. In addition, the line has an aeroponic irrigation system in which the roots hang in the air and are supplied with water and nutrients via a spray mist. Optimal illumination of the plants is ensured throughout the entire cultivation period by modular LED technology, and additional CO2 fertilisation increases the quality and harvest quantity.

Indoor production systems such as OrbiPlant have specific challenges in terms of their technical resilience, resulting from the closed environment combined with high plant densities. For this reason, scientists at the Fraunhofer IME – together with the Fraunhofer Institute for Production Technology (IPT) – have investigated relevant malfunctions in basil production.

A combination of science and business

The objective of the scientists was to derive approaches for establishing a resilient production process. The researchers induced technical and plant-specific incidents on two OrbiPlant lines, which could be clearly detected using suitable sensor technology and real-time recording of the plant data. This resilience approach goes beyond simple monitoring with error notification, and can make an important contribution to securing the supply of high-quality food in the future.

The vision of indoor farming can only be realised in an interdisciplinary way with a combination of science and business as well as agriculture and production technology. The Inhouse Farming – Feed & Food Show gives the industry a new B2B platform. In addition to presenting pioneering technologies, it serves to build knowledge and facilitate an interactive exchange on best practices, Marcus Vagt says. Visitors to the trade fair will gain an up-to-date overview of production systems for sustainable agriculture, and can also learn about the challenges of indoor crop production.