Five years of accumulated data have demonstrated the effectiveness of techniques for conducting long-term field studies on the uptake of transuranium elements by plants from soil. Contaminated soil is placed in small containers which provide reasonably natural environmental conditions for field-grown plants as well as complete control of the radionuclides. The 1-m-long containers are constructed from 13.2-cm-diameter polyvinylchloride (PVC) pipe. The bottoms of the pipe are permanently capped. The containers, filled with contaminated soil spiked in various configurations, are placed vertically in the ground inside liners made of 15.7-cm-diameter PVC pipe. This allows the containers to be removed easily for weighing, cropping, or coring to observe the vertical I distribution of the containment in the soil profile. The containers are maintained inside large fenced exclosures to prevent animals from gaining access to the contaminated plants.