title: Dicyandiamide and 3,4-dimethyl pyrazole phosphate decrease N2O emissions from grassland but dicyandiamide produces deleterious effects in clover.
abstract: The application of nitrogen fertilisers leads to different ecological problems such as nitrate leaching and the release of nitrogenous gases. N2O is a gas involved in global warming, therefore, agricultural soils can be regarded as a source of global warming. Soil N2O production comes from both the nitrification and denitrification processes. From an ecological viewpoint, using nitrification inhibitors with ammonium based fertilisers may be a potential management strategy to lower the fluxes of N2O, thus decreasing its undesirable effect. In this study, the nitrification inhibitors (NIs) dicyandiamide (DCD) and 3,4-dimethyl pyrazole phosphate (DMPP) have been evaluated as management tools to mitigate N2O emissions from mineral fertilisation and slurry application in grassland systems (experiments 1 and 2), and to assess the phytotoxic effect of these inhibitors per se on clover (experiment 3). Both nitrification inhibitors acted in maintaining soil nitrogen (N) in ammonium form, decreasing cumulative N2O emissions. DCD, but not DMPP, produced phytotoxic effects and yield reduction in white clover. A nutrient imbalance, which led to a senescence process visually observed as chlorosis and necrosis at the border of the leaves, was noted.
authors.affiliation: Dpto Biología Vegetal y Ecología, UPV/EHU, Apdo 644, 48080 Bilbao, Spain. gvbmebex@lg.ehu.es
authors.forename: Xana Melissa Belastegui
authors.initials: XM
authors.lastname: Macadam
authors.forename: Agustin
authors.initials: A
authors.lastname: del Prado
authors.forename: Pilar
authors.initials: P
authors.lastname: Merino
authors.forename: José María
authors.initials: JM
authors.lastname: Estavillo
authors.forename: Miriam
authors.initials: M
authors.lastname: Pinto
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Murua
mesh_terms: D005308:Fertilizers / Q000032:analysis; D017752:Greenhouse Effect; D006146:Guanidines / Q000494:pharmacology* / Q000633:toxicity; D008372:Manure / Q000032:analysis; D029902:Medicago / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D017672:Nitrogen Compounds / Q000378:metabolism / Q000494:pharmacology; D009609:Nitrous Oxide / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006109:Poaceae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology* / Q000633:toxicity; D012987:Soil / Q000032:analysis; D013030:Spain
chemical_list: C433304:3,4-dimethylpyrazole phosphate; D005308:Fertilizers; D006146:Guanidines; D008372:Manure; D017672:Nitrogen Compounds; D011720:Pyrazoles; D012987:Soil; D009609:Nitrous Oxide; C004711:dicyandiamido