Industry, sector and description for Universal Display. Universal Display researches, develops, and sells organic light emitting diode (OLED) technologies and materials for the flat-panel display industry.
The first requirement for all master horizons other than O horizons is that they are composed mostly of mineral material. It is very important to be able to differentiate organic from mineral material. Dark color of the A horizon is due to the mixing of humus with mineral.
I believe soil composition does change signiflcanffy as altitude increases. First, the depth of the O/A and the B soil horizons both decrease substantially. Second, because snowfall temperature decreases zs altitude increases, the temperature of both soil horizons decreases as altitude increases. Third, the amount of organic material decreases because it becomes more difficult for plants to survive at higher altitudes.