In mid November the world population surpassed 8 billion, a figure three times higher than in the mid 20th century. At the same time, climate change is increasingly challenging food production. Scientists have long warned that current methods may not meet rising demand. As a result, researchers are exploring alternatives to boost efficiency in farming.
A team from Linköping University in Sweden, working under the bioelectronics program, developed a system called eToprak. It delivers electrical stimulation to plant roots and surrounding environments through a hydroponic setup.
The results are striking. Barley seedlings show an average growth increase of about 50 percent in dry weight 15 days after the electrical stimulation. Both roots and shoots demonstrate enhanced growth, suggesting that the stimulation triggers processes during the growth period that influence the plant’s developmental trajectory beyond the immediate effect.
The findings indicate that a single treatment can yield benefits throughout the plant’s growth without requiring continuous stimulation.
Researchers Eleni Stavrinidou and Alexandra Sandéhn credit the eSoil interface with a low energy draw that promotes plant growth. Thor Belkhed
eSoil soil, unlike traditional hydroponic crops that rely on mineral substrates, uses less energy and is primarily composed of cellulose, the most abundant polymer, mixed with a conductive polymer called PEDOT. This combination is not entirely new, but it marks the first time it has been used to grow plants and create this kind of interface with them.
Low energy consumption device
In hydroponic farming, plants grow without soil, requiring only water, nutrients, and a substrate for root attachment. The system circulates water so each seedling receives exactly the nutrients it needs, minimizing water use and keeping all nutrients within the system. This level of efficiency is difficult to achieve in traditional agriculture.
Hydroponics supports the cultivation of vegetables and leafy greens, and is particularly advantageous in areas with limited arable land, poor soil, or challenging environmental conditions. Soilless farming can enable urban food production, especially in highly controlled environments, according to Eleni Stavrinidou, professor at Linköping University’s Organic Electronics Laboratory and leader of the Electronic Facilities group.
The hydroponic system can also be scaled vertically in large towers to maximize space usage. Current crops grown this way include lettuce and herbs, with some vegetables. Grains are generally not grown hydroponically except for animal feed.
There are several considerations for adopting hydroponics with eSoil for large scale indoor agriculture. One notable advantage is that eSoil operates with very low energy consumption and, in principle, can run on photovoltaic energy, the report states. (Source: Proceedings of the National Academy of Sciences, 2023.)
Increase in crop yield
This study opens a path for using physical stimuli to improve plant growth and to deepen understanding of how plants respond to electric fields, advancing hydroponic farming methods.
Since barley is also used as animal feed, higher biomass at early stages could translate into more feed materials with the same resources. Researchers hope this study will spark broader exploration into the effectiveness of this approach and the potential for smart, sustainable soilless scaffolding materials to boost yields. More work is needed to determine whether the method works across other plant species and to uncover the underlying biological mechanisms at play.
Previous studies have used higher voltages to stimulate roots. The advantage of the eSoil approach lies in its low energy consumption and the absence of high voltage hazards.
While hydroponics is unlikely to solve global food security on its own, Stavrinidou notes that it can significantly aid regions with scarce arable land and harsh climates by offering a viable, energy-efficient farming option.
………. Under consideration are future experiments, broader species testing, and a deeper exploration of how this interface affects plant physiology and growth dynamics. (Source: PNAS 2023.)