Transformations of Amide Nitrogen in Soils1
- W. T. Frankenberger and
- M. A. Tabatabai2
Amides added to soils are hydrolyzed to ammonium (NH+4) and their corresponding carboxylic acids. Studies of transformations of amide-N in soils deserve attention because amides have potential as nitrogen (N) fertilizers. In this work, the transformations of amide-N (200 µg/g of soil) were studied in field-moist soils incubated under aerobic conditions at 30°C for 14 days. The recovery of inorganic N (as NH3, NH4+, NO2-, and NO3-) produced from 25 amides or their derivatives was determined and compared with those obtained with (NH4)2SO4 and urea added to five soils. Results showed that with the exception of cyanamide, dicyandiamide, benzenesulfonamide, and sulfanilamide, which resisted decomposition, all other amides were readily hydrolyzed in the five soils used. With most of the amides studied, the inorganic N produced was accumulated as NO3-. The recovery of nitrogen as NO3- from each of five soils treated with urea, acetamide, propionamide, 2-cyanoacetamide, n-butyramide, oxamide, or DL-lactamide was <50% of the N added. The average percentage of NH4+-N recovered from the soils used exceeded 40% of the total inorganic N produced when thioacetamide, fluoroacetamide, and 2-chloroacetamide were added to soils. With one sandy soil, the addition of urea, formamide, N-benzylformamide, and p-nitrobenzamide resulted in accumulation of NO2-, ranging from 5 to 21% of the inorganic N recovered. Appreciable amounts of NH3 were volatilized when formamide, acrylamide, 2-cyanoacetamide, p-nitrobenzamide, and urea were applied to soils, especially from the sandy soil. The average recovery of amide-N as inorganic N from the five soils used ranged from 4% with dicyandiamide to 100% with formamide.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .