Measuring the Release of Ammonia from Leaves

Ammonia (NH₃) is released from the leaves to the atmosphere when atmospheric NH₃ concentration is low; in contrast, when atmospheric NH₃ concentration is high, NH₃ in the atmosphere is absorbed by the leaves. Some previous studies have examined relationships of such NH₃ gas exchange with photorespiration, because a NH₃ production reaction is involved in the photorespiratory pathway. NH₃ compensation point (χ_NH3) is known as a parameter that represents an NH₃ emission potential of the leaves. Two main procedures for determining the χ_NH3: "gas exchange method" and "apoplast extraction method" are explained in this chapter.