In agricultural systems, they are believed to aid nutrient uptake as the acids can bind with minerals, a process known as chelation, and then allow the minerals to be taken up by the plant. Humic and fulvic acids have been found to promote plant height and root density when applied in low doses. It can increase the movement distance of phosphorus in the soil, convert invalid phosphorus into effective phosphorus, and promote the absorption of phosphorus by roots. Fulvic acid can absorb and store potassium ions and increase the content of effective potassium.