Growth characteristics of shallots and absorption of Mg ions dissolved from serpentinites

Magnesium (Mg)-rich water or food is highly beneficial to human health. Shallots are used in cooking, have simple growth conditions and have a short growth cycle. In this study, natural serpentinite was ground into powder (particle size: 50–200 nm), heated at high temperatures (400 and 800°C) and then dissolved in water of different temperatures (25, 60 and 100°C) to prepare natural magnesium-containing water. The experimental results indicated that natural serpentine minerals contain magnesium silicate, which has ionic properties and a high electrical conductivity. The dissolution of magnesium ions increased with the temperature of the distilled water. The heat-treated powder displayed higher crystallinity. However, the dissolution of magnesium was lower for the solution containing the powder heated to 800°C than for the solution containing the powder heated to 400°C. The 400°C powder exhibited favorable crystallinity and a low level of impurities, and its interlayer spacing did not change. The shallots grown with natural magnesium-containing water (magnesium shallots) had a high concentration of magnesium ions in their white and green parts. Such shallots can be provided by food platforms, and eating such shallots can help one meet the daily magnesium intake requirement of 300 mg/l for humans.