DC current applied to soil drives measurable increases in plant mineral uptake, especially calcium and zinc.
Direct current through soil electrodes creates an electroosmotic gradient that mobilizes and concentrates mineral ions into plant tissue. In African nightshade, 16V DC produced leaf calcium +27.5%, stem zinc +244.4%, and stem magnesium +15.6% compared to untreated controls — demonstrating that electrical stimulation can function as a practical mineral-enrichment tool.
Applying DC current through soil via plate electrodes creates an electroosmotic driving force that actively migrates mineral ions from the soil solution into root tissue and upward through the plant. The effect is not subtle: in a controlled greenhouse trial on Solanum scabrum (African nightshade) using 10 h/day of DC stimulation for 12 days, mineral content in treated plants exceeded controls by large margins at 16V — leaf calcium increased +27.5%, stem zinc +244.4%, and stem magnesium +15.6%.
The zinc finding is particularly striking because zinc deficiency is the most widespread micronutrient deficiency in global agriculture. A 244% increase in stem zinc concentration — achieved with no fertilizer amendment, just electrical stimulation — suggests that DC current can unlock existing soil zinc reserves that would otherwise be immobile or unavailable to roots. The mechanism is electroosmotic: the applied voltage creates a cation migration pathway that preferentially concentrates positively charged mineral ions at the anode side, which the plant roots intercept.
Heavy metal content was also elevated under DC treatment, consistent with the non-selective nature of electroosmotic ion migration. However, all measured heavy metal concentrations in the Gogo 2016 trial remained within EFSA safety limits for edible crops, suggesting the effect can be managed within food safety thresholds at moderate voltages and exposure durations.
Source: Gogo et al., Journal of Applied Botany and Food Quality 89 (2016), pp. 60–67. DOI: 10.5073/JABFQ.2016.089.007