A combination of X-ray absorption spectroscopy and computational methods has revealed the unique bonding environment of potassium associated with organic acids.

Potassium is an essential element for plant growth. However, soils generally have low amounts of potassium readily available to plants. Luckily, soils contain potassium in soil minerals, and there are many species of microbes that can weather mineral surfaces by secreting organic acids that dissolve the minerals, thereby releasing potassium.

A recent study published in The Journal of Chemical Physics shows that the bonding environment of potassium in different organic acids has different signatures that can be detected using X-ray techniques. The signature of the bonding environment can inform whether potassium is associated with carbon, nitrogen, or oxygen.

Microbial mineral weathering has been shown to be a promising pathway to sustainably increase the availability of potassium (K) to plants. However, the mechanisms underlying microbial K transformations are poorly resolved.