It is crucial that landowners have a clear understanding of how soils, plants, and animals interact with each other to cause a poisonous reaction so that Se poisoning can be prevented. Since most Se in soil is not available to plants, Se uptake by plants is not closely related to the total amount of Se in the soil. Therefore, a chemical procedure should be used that extracts only the Se that is available to plants. Selenate, one of many forms of selenium, is the predominant form of Se in Colorado s high pH, well-aerated soils. Selenate is the form of Se that is most soluble, most mobile in soils, and most readily taken up by plants.
Seleniferous soils tend to be heavy-textured or clayey.
Se level, heavier-textured soils tend to support plants with lower Se levels than sandy soils. Se levels themselves. Many Colorado soils have higher pH in the subsoil than in the surface. This higher pH makes Se in the subsoil more available to plants, hence more dangerous to livestock. Deep-rooted plants extract Se from deep within the soil.