13.7 MB (739.3 KB compressed)
1769 x 2700 pixels
15.0 x 22.9 cm ⏐ 5.9 x 9.0 in (300dpi)
SCIENCE SOURCE / SCIENCE PHOTO LIBRARY SCIENCE SOURCE / SCIENCE PHOTO LIBRARY
As part of long-term experiments to learn the effects of different land-use sytems on crops and soils, a chemist extracts nitrogen from soil samples taken from test plots at Pendleton, Oregon.
Model release not available. Property release not required.