Robotic Soil Instrument

Soybeans are an important crop for global food security. Every year, soybean yields are reduced by

numerous soybean diseases, particularly the soybean cyst nematode (SCN). It is difficult to visually

identify the presence of SCN in the field, let alone its population densities or numbers, as there

are no obvious aboveground disease symptoms. The only definitive way to assess SCN population

densities is to directly extract the SCN cysts from soil and then extract the eggs from cysts and count

them. Extraction is typically conducted in commercial soil analysis laboratories and university plant

diagnostic clinics and involves repeated steps of sieving, washing, collecting, grinding, and cleaning.

Here we present a robotic instrument to reproduce and automate the functions of the conventional

methods to extract nematode cysts from soil and subsequently extract eggs from the recovered

nematode cysts. We incorporated mechanisms to actuate the stage system, manipulate positions

of individual sieves using the gripper, recover cysts and cyst-sized objects from soil suspended in

water, and grind the cysts to release their eggs. All system functions are controlled and operated

by a touchscreen interface software. The performance of the robotic instrument is evaluated using

soil samples infested with SCN from two farms at different locations and results were comparable

to the conventional technique. Our new technology brings the benefits of automation to SCN soil

diagnostics, a step towards long-term integrated pest management of this serious soybean pest.