Project: New Method for Quantification of Ammonia Volatilization from Agricultural Field Plots

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Principal investigators: H. A. Torbert

Associated with: USDA-ARS National Soil Dynamics Laboratory

Project Summary:

A modified low-cost method of measuring ammonia (NH3) volatilization was developed for use with static chambers. This technique utilizes glass tubes coated with oxalic acid placed inside the chambers to adsorb NH3 being evolved from soil. The advantage of this procedure is that it can be used to quantify NH3 emissions from field plots used for evaluating multiple management practices in an agricultural field. A correction factor is required to accurately estimate NH3 levels inside the static chambers. In addition, if the static chambers are made of an NH3 absorbing material, another correction is needed to obtain an accurate estimate of NH3 air concentration. Values measured with this technique can be used to estimate NH3 efflux rates and to determine the efficacy of agricultural practices that could potentially suppress volatilization losses evaluated from research plots.   The following publication describes the modified static chamber method and validation by comparison with NH3 gas detector tubes.

Chapman, K.E., H.A. Torbert, and D.B. Watts.  2016.  Validation of a new method for quantification of ammonia volatilization from agricultural field plots.  European Agrophysical J. 3:76 -90.