An inexpensive robotic gantry to screen and control soil moisture for plant experiments.

Controlling water content in soil is a recurrent and labor intensive operation on almost any experiment about plant physiology. Here we describe a robotic gantry to measure and control soil moisture in pots that is modular, inexpensive, easy to build, accurate, precise, and reliable. Machines can be stacked into industrial shelves, coupled with other control systems to conduct multifactorial experiments, and adjusted to accommodate numerous pots of any size allowing for experiments with limitless specimen capacity in terms of height and specimen count.