Technical Abstract: In this study we evaluated the boron (B) adsorption/desorption reaction in six soils and examined the extent to which organic matter content, as well as incubation time affected B release. Six soils varying in initial pH, clay content, and were selected for the study. Adsorption experiments were carried out to determine B adsorption isotherms using 0.01 M NaCl solutions containing 0-100 mg B kg-1. The soils were equilibrated for 23 hours. Boron desorption was investigated after replacing 10 mL aliquots with B-free 0.01 M NaCl three times. Three of the soils were also spiked with 0-100 mg B kg-1 and equilibrated up to 23 months at field capacity water content in a temperature controlled room at 25C. At various intervals subsamples were extracted with DTPA-sorbitol, boiling water, and 0.1 M NaCl. The B adsorption/desorption behavior of four soils was found to be nonhysteretic, regardless of organic matter content. The behavior of two soils was slightly hysteretic, likely due to difficulties in the experimental procedure. Our results do not support the hypothesis that B desorption hysteresis increases in soils with increasing organic matter content or decreases with increasing soil pH.