Soil N Losses by Denitrification Evaluated Using the N-15 Tracer Method

Author(s)

Milagres, J. J. M. ; Sant Ana Filho, C. R. ; Schoninger, E. L. ; Trivelin, P. C. O. ; Bendassolli, J. A.

• Document type: Journal article
• Source: Communications in Soil Science and Plant Analysis; v. 47, n. 13-14, p. 1709-1719, 2016.
• Web of Science Citations: 0

Abstract

Molecular nitrogen (N-2) and nitrous oxide (N2O) generated by denitrification increase N losses in the soil-plant system. This study aimed to quantify N-2 and N2O from potassium nitrate ((KNO3)-N-15) applied to soils with different textures and moisture contents in the absence and presence of a source of carbon (C) using the N-15 tracer method. In the three soils used (sandy texture (ST), sandy clay loam texture (SCLT), and clayey texture (CT)), three moisture contents were evaluated (40%, 60%, and 80% of the water holding capacity (WHC)) with (D+) and without (D-) dextrose added. The treatments received 100mgNkg(-1) (KNO3 with 23.24 atom% N-15). N-2 emissions occurred in all of the treatments, but N2O emissions only occurred in the D+ treatment, showing increases with increasing moisture content. SCLT with 80% WHC in the D+ treatment exhibited the highest accumulated N emission (48.26mgkg(-1)). The N-15 balance suggested trapping of the gases in the soil. (AU)

• FAPESP's process: 13/08980-4 - Quantification of emissions of N2O and N2 by isotopic method (15N) in soils cultivated with sugar cane
• Grantee: José Albertino Bendassolli
• Support type: Regular Research Grants