  To autonomously collect soil in uncultivated terrain, robotic arms must
distinguish between different amorphous materials and submerge themselves into
the correct material. We develop a prototype that collects soil in
heterogeneous terrain. If mounted to a mobile robot, it can be used to perform
soil collection and analysis without human intervention. Unique among soil
sampling robots, we use a general-purpose robotic arm rather than a soil core
sampler.
