Petrichor
The smell of the earth after rain. It contains:
· essential oils of plants and abscisic acid, slowing down the growth of plants and seeds in unfavourable conditions, including during droughts;
· geosmin — a product of the life activity of streptomycete bacteria living in the soil attractive for springtails, small soil insects. By eating the streptomycetes, the springtails spread them; P. appears when water falls onto the soil during rain, releasing oils and geosmin.
Location: the windowpanes and windows in the lecture room.