Ask the plants directly: Understanding plant needs using electrical impedance measurements

Food security is a major problem nowadays. Ensuring enough food for the entire human population is becoming harder due to climate change and world population growth. Smart agriculture is a promising solution: integrating sensors and data analysis in agriculture is leading to a reduction of food production waste and an increase in production yield. However, currently environmental monitoring is not sufficient since different plants may have disparate reactions even if their environmental conditions are similar. This paper shows a novel way of under- standing plant status based on direct measurement of in vivo stem electrical impedance. This was achieved with a system designed by the authors and validated by showing relations (correlation and Granger’s causality) between stem electrical impedance and environment parameters. Validation was accomplished by monitoring and analyzing multiple plants at the same time. Statistical analysis showed a correlation of up to 95% between impedance and soil moisture, and that soil moisture variations caused variation in the impedance of the plants.