A tractor mounted sampler was constructed which allows large soil columns to be obtained rapidly and with minimal physical effort. The machine utilizes the hydraulic system of a tractor to push a steel sampling cylinder containing 30.5-cm id. polyvinyl chloride (PVC) pipe into the soil, after which the hydraulic cylinder is retracted to pull the pipe and enclosed soil from the ground. Columns 68 cm in length were taken with a hydraulic cylinder pressure of approximately 10 MPa. Soil separated evenly at the bottom of the columns, and compaction was measured to be approximately 5%. This is a relatively simple and rapid method for obtaining large soil columns for use in pesticide leaching studies.

Barnyardgrass [Echinochloa crus-galli (L.) Beauv. ♯3 ECHCG], originally from Europe and India, now ranges from latitude 50 N to 40 S, in both temperate and tropical habitats (12). It is a serious weed problem in 42 countries and is found in at least 27 more (11). It is the world's principal weed of rice (12) and likely has been for a long time: barnyardgrass is recognizable in Chinese drawings from 1590 (13).