NMSU Desert Soils Notes

• NMSU - Desert Soils: Unlocking the Past, Understanding the Future - Pics


• S. NM


• Arid lands are fragile and can degrade quickly


• clay topsoil, calcium carbonate (caliche) subsoil


• after civil war had resources to bring in water to the desert


• overgrazing helped wipe out grama grass, but was only one part, droughts are the killer after overgrazing


• mesquite stools spread when cows spread seeds after grass was gone, mesquite won the war for water and colonized the areas with thousands of stools, the surrounding land was blown away,


• carbon dated charcoal from 7000-4500, 2000, and 1100 years ago


• soil tell story of changes in the last 10000 years,


• depth of caliche is influenced by rainfall amounts 8"/yr, 10" deep caliche layer 11"/yr, 20" deep caliche layer 16"/yr, 41" deep caliche layer


• are desert lands a source or sink for CO2? Acid rain can dissolve calcium carbonate or calcium carbonate may lock up atmospheric CO2


• clay also is blown in, filters into a layer/horizon above the caliche,