Emissão de óxido nitroso em cebola (Allium cepa L.) cultivada sob Sistema de Plantio Direto Agroecológico

Agriculture is a major contributor to increased emissions of nitrous oxide (N2O) to the atmosphere.The objective of this study was to evaluate N2O emissions in onions (Allium cepa L.)grown under No-Tillage Vegetable Systems (NTVS) of agroecological basis and in conventionaltillage system (CT). N2O emissions were evaluated in NTVS with addition of oilseed radish(OR), black oat (AP) and fallow (FW) and a treatment under CT. N2O emissions (kg N-N2O ha-1) were affected by the different management systems, being approximately 2.6 times greaterin the treatment with OR (5.28 ± 1.04 kg N-N2O ha-1). The use of BO and FW residues didnot increase N2O emissions to the atmosphere and could be an efficient alternative to reduceemissions of this gas in the NTVS. The use of oilseed radish as a cover crop should be decidedon the basis of other advantages