Lack of increased availability of root-derived C may explain the low N2O emission from low N-urine patches

Publication: Research - peer-reviewJournal article – Annual report year: 2006

View graph of relations

Urine deposition on grassland causes significant N2O losses, which in some cases may result from increased denitrification stimulated by labile compounds released from scorched plant roots. Two 12-day experiments were conducted in C-13-labelled grassland monoliths to investigate the link between N2O production and carbon mineralization following application of low rates of urine-N. Measurements of N2O and CO2 emissions from the monoliths as well as delta C-13 signal of evolved CO2 were done on day -4, -1, 0, 1, 2, 4, 5, 6 and 7 after application of urine corresponding to 3.1 and 5.5 g N m(-2) in the first and second experiment, respectively. The delta C-13 signal was also determined for soil organic matter, dissolved organic C and CO2 evolved by microbial respiration. In addition, denitrifying enzyme activity (DEA) and nitrifying enzyme activity (NEA) were measured on day -1, 2 and 7 after the first urine application event. Urine did not affect DEA, whereas NEA was enhanced 2 days after urine application. In the first experiment, urine had no significant effect on the N2O flux, which was generally low (-8 to 14 mu g N2O-N m(-2) h(-1)). After the second application event, the N2O emission increased significantly to 87 mu g N2O-N m(-2) h(-1) and the N2O emission factor for the added urine-N was 0.18%. However, the associated C-13 signal of soil respiration was unaffected by urine. Consequently, the increased N2O emission from the simulated low N-urine patches was not caused by enhanced denitrification stimulated by labile compounds released from scorched plant roots.
Original languageEnglish
JournalNutrient Cycling in Agroecosystems
Issue number1-3
Pages (from-to)91-100
StatePublished - 2006

Bibliographical note

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the publisher

CitationsWeb of Science® Times Cited: 7
Download as:
Download as PDF
Select render style:
Download as HTML
Select render style:
Download as Word
Select render style:

ID: 6206213