CORVALLIS, Ore. - It's a simple equation: If you want to grow better plants, you first need to understand the soil. "The texture of a soil is its proportion of sand, silt and clay," said James Cassidy ...

ANN ARBOR, MI -- With a gentle hand, Mark Meier guides a long, thin tube of clay from a machine nozzle onto a slab of freshly rolled clay laid out on a wooden board. The two clays meet. Meier sits ...