Nitrous oxide (N2O) is a gas which under certain soil and environmental conditions is produced from both soil mineralised and fertiliser nitrogen (N) by de-nitrifying bacteria. For the farmer this represents a loss of soil fertility and/or loss of applied fertiliser. Additionally, when in the atmosphere N2O is a potent greenhouse gas. This is why it is important to minimise the loss of valuable soil and fertiliser N to the atmosphere through these processes. This BMP fact sheet sets out how this can be achieved by farmers producing vegetables.