02634naa a2200325 a 450000100080000000500110000800800410001902400320006010000160009224501170010826000090022550000470023452016880028165000120196965000320198165000100201365000180202365300170204165300200205865300180207865300370209670000230213370000180215670000110217470000160218570000180220170000150221970000190223477300550225310592652019-10-10       2018    bl uuuu     u00u1 u    #d7 a10.1002/jpln.2017003932DOI1 aCIGANDA, V.  aSoil nitrous oxide emissions from grasslandbpotential inhibitor effect of hippuric acid.h[electronic resource]  c2018  aArticle history: Accepted 01 October 2018.  aAbstract: In grassland systems, cattle and sheep urine patches are recognized as nitrous oxide (N2O) emission hot spots due to the high urinary nitrogen (N) concentrations. Hippuric acid (HA) is one of the constituents of ruminant urine that has been reported as a natural inhibitor of soil N2O emissions. The aim of this study was to examine the potential for elevated ruminant urine HA concentrations to reduce N2O emissions, in situ, on an acidic heavy clay soil under poorly drained conditions (WFPS > 85%). A randomized complete block design experiment with three replications and four treatments was conducted using the closed-static-flux chamber methodology. The four treatments were applied inside the chambers: control with no artificial urine application (C), control artificial urine (U), and enriched artificial urine with two rates of HA (55.8 and 90 mM, U+HA1, U+HA2). Soil inorganic-N, soil dissolved organic carbon (DOC), soil pH as well as N2O and methane (CH4) fluxes were monitored over a 79-d period. Although N2O emissions were not affected by the HA enriched urine treatments, U+HA2 positively affected the retention of N as NHþ4 until day 3, when the soil pH dropped to values < 5. Subsequently, as a consequence of rainfall events and soil acidification, it is likely that leaching or sorption onto clay reduced the efficacy of HA, masking any treatment differential effect on N2O emissions. Moreover, CH4 fluxes as well as DOC results reflected the soil anaerobic conditions which did not favour nitrification processes. Further research is needed to determine the fate of HA into the soil which might clarify the lack of an in situ effect of this compound.  aBOVINOS  aGASES DE EFECTO INVERNADERO  aORINA  aOXIDO NITROSO  aBOVINE URINE  aHEAVY CLAY SOIL  aN2O EMISSIONS  aNATURAL NITRIFICATION INHIBITION1 aLÓPEZ-AIZPÚN, M.1 aREPULLO, M.A.1 aWU, D.1 aTERRA, J.A.1 aELUSTONDO, D.1 aCLOUGH, T.1 aCARDENAS, L.M.  tJournal of Plant Nutrition ans Soil Science, 2018.