This unit on soil science contains a 16-page student section that covers soil components (clay, sand, and silt, loam, humus, soil texture (including the texture triangle), soil horizons, and movement of water through soil. Five discovery labs are embedded within the student hand-out: (1) soil make-up (visual inspection), (2) describing soil (by feel and settling), (3) the ribbon test for clay content (including an adapted method for small hands), (4) separating sand, silt, and clay by sedimenta