S08 - Session P3 - Design and development of automatic nutrient sensors for efficient water and nutrient management in vertical farming systems

Authors: Heike Mempel *, Murtaza Hasan, Mohamed Bourouah, Markus Abel, Sabine Wittmann, Ivonne Jüttner

Vertical farming is a revolutionary idea that would allow cities a greater self-sufficiency by growing plants locally with maximum productivity. This technique responds to the challenges posed by the projected decreasing farmland availability, growing population and increased urbanization. A strong growth of vertical farming can be expected for the next decade. A crucial advantage of vertical farming over conventional farming is the more efficient control of all cultivation parameters like climate condition or nutrient concentrations as well as the recovery of water. Hydroponic, aeroponic and aquaponic culture are important technologies involved in vertical farming to grow value plant based raw materials, vegetables, flowers, herbs, selected fruits, seedlings and fish year-round. Currently nutrient solution management is limited to adjusting the conductivity and pH of the solution by supplying stock solutions with fixed ion ratios. Ion specific nutrient management holds the potential to increase nutrient use efficiency and yields through continuous monitoring and adjustment of ion concentrations. Potentiometric and photometric sensors for Nitrogen, Phosphorous, Potassium, Magnesium, Calcium, EC and pH are designed and developed with an accuracy and tolerance of 5-10 ppm and 1-2 ppm respectively at Hahn-Schickard Germany. Reference values of major and micro nutrient sensors for leafy green vegetables are developed at IARI India for testing the developed sensors. The Applied Science Centre for Smart Indoor Farming at the HSWT Germany shall test the sensor platform at its indoor vertical farm for refinement and final prototype development. The developed automatic sensor array with integrated IoT shall be tested at IARI Delhi India inside a vertical farm greenhouse to finalize the prototype. The main goal of the SensVert project is to develop an automated ion-specific fertigation management for vertical farming systems. Based on a better understanding of the plant-environment-interactions, optimized strategies for nutrient supply can be developed.