analysis clayminerals conservation cropsandsoils earthsciences forestsandforestry forestsoils geography geology geophysics/geodesy mineralogy mineralresources minesandmineralresources nat038000 naturalresources nature northernhemisphere physicalgeography pollution quality research saltsin sedimentology soilconservation soilecology soilfertility soilformation soilphysics soilpollution soils soilsalinization soilscience soilstructure water waterchemistry