While hydroponic farms do allow a lot of crop plants to be grown in a relatively small space, they would certainly be a better alternative to traditional farms if those plants grew faster. That could soon be the case, thanks to the development of electrically conductive "eSoil."
Although hydroponic farms don't use actual soil, they do utilize a cultivation substrate for the plants' roots to grow into. Mineral wool is frequently used for this purpose, although its production requires a great deal of energy, plus it doesn't biodegrade once discarded.
Given the fact that electrical stimulation of the roots had already been shown to boost plant growth, scientists from Sweden's Linköping University set out to develop an alternative substrate that was both eco-friendly and highly electrically conductive.
The result was the eSoil, a porous material which is made of plant-derived cellulose nanofibers mixed with a very conductive polymer known as PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate).
In lab tests conducted over a 15-day period, one group of barley plants was grown in eSoil while another group was grown in conventional mineral wool. The eSoil plants grew without stimulation for the first five days, after which their roots were mildly electrically stimulated for another five. After a further five days without stimulation, the barley plants were harvested.
It was found that when compared to the control group, the growth of the eSoil plants had been boosted by an average of 50%. The extra growth was observed in both the roots and the shoots. And unlike the previous studies in which high-voltage electricity was used to boost plant growth, the eSoil only required a safer, more energy-efficient low-voltage current.
"We can get seedlings to grow faster with less resources," said the lead scientist, Assoc. Prof. Eleni Starvrinidou. "We don’t yet know how it actually works, which biological mechanisms that are involved. What we have found is that seedlings process nitrogen more effectively, but it’s not clear yet how the electrical stimulation impacts this process."
A paper on the research was recently published in the journal Proceedings of the National Academy of Sciences.
Source: Linköping University
