Release of Native and Amended Boron From Arid Zone Soils After Varying Incubation TimesGoldberg, Sabine; Suarez, Donald L.Soil Science: May 2011 - Volume 176 - Issue 5 - pp 213-217 doi: 10.1097/SS.0b013e3182147ceb Technical Article Abstract Author Information In this study, we evaluated the boron (B) release from soils containing elevated native B and examined the extent to which incubation time affected B release. Five soils varying in initial pH and clay content were selected for the study. The soils were spiked with five varying doses of B as H3BO3 (0-100 mg B kg−1) and equilibrated for a total of 5 months at field capacity water content. The soils were incubated in a temperature-controlled room at 25°C. At monthly intervals, the soils were thoroughly mixed and subsamples were removed. The subsamples were extracted with diethylenetriaminepentaacetic acid-sorbitol, boiling water, and 0.1 M NaCl to provide various B extraction protocols. Boron desorption decreased as a function of time for at least some of the extractions and treatments for all five soils. This is consistent with published literature that added B becomes less extractable with increased incubation time. Comparison between the three extractants revealed no statistically significant differences in amounts of adsorbed B for three of the soils. For the two other soils, the order of desorbed B amount was hot water soluble < 0.1 M NaCl extractable < diethylenetriaminepentaacetic acid-sorbitol extractable. The decrease in B release with respect to incubation time approached zero for all five soils for most of the extractant solutions, as evidenced by slopes that were not statistically significantly different from zero at the 95% level of confidence for almost all treatments of all three extractions. This result suggests that a 5-month incubation is adequate to obtain an accurate assessment of the amount of B available for release. Because the decrease in extractable B with time for four of the soils is not large, a very good indication of extractable soil B can be obtained from a 1-month incubation study. USDA-ARS, U.S. Salinity Laboratory, 450 W. Big Springs Road, Riverside, CA 92507. Dr. Sabine Goldberg is corresponding author. E-mail: firstname.lastname@example.org Received September 28, 2010. Accepted for publication February 7, 2011. © 2011 Lippincott Williams & Wilkins, Inc.