Assay of urease activity in soils

doi:10.1016/0038-0717(72)90064-8

Soil Biology and Biochemistry

Volume 4, Issue 4, November 1972, Pages 479-487

https://doi.org/10.1016/0038-0717(72)90064-8 Get rights and content

Abstract

A simple and precise method of assaying urease activity in soils is described. It involves determination of the ammonium released by urease activity when soil is incubated with tris(hydroxymethyl)aminomethane (THAM) buffer, urea solution, and toluene at 37°C for 2 h, ammonium release being determined by a rapid procedure involving treatment of the incubated soil sample with 2.5 M KC1 containing a urease inhibitor (Ag₂SO₄) and steam distillation of an aliquot of the resulting soil suspension with MgO for 3.3 min. Studies reported showed that the optimal buffer pH and substrate (urea) concentration for assay of soil urease activity using THAM buffer are 9.0 and 0.02 M, respectively, and that the method described is satisfactory for assay of urease activity in ammonium-fixing soils.

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Assay of urease activity in soils

Abstract

Soil Biol. Biochem.

Soil Biol. Biochem.

Arch. Biochem. Biophys.

Determination and isotope-ratio analysis of different forms of nitrogen in soils—I. Apparatus and procedure for distillation and determination of ammonium

Determination and isotope-ratio analysis of different forms of nitrogen in soils—3. Exchangeable ammonium, nitrate, and nitrite by extraction-distillation methods

Hydrogen Ions

The nature of the catalyst causing the hydrolysis of urea in soils

Soil Sci.

The occurrence and origin of urease like activities in soils

Soil Sci.

Fertilizers in 2000 A.D.

Urea conversion to ammonia in waterlogged soils

Urea as a fertilizer

Soils Fertil.