Soils are a non-negligible source of NO in a UK suburban greenspace and SE Australian Eucalyptus forest

•Soil emissions were a continuous source of NO to the atmosphere at both sites.•Meteorological conditions affect soil NO emission.•Diel variations of solar radiation and VPD partly explain soil NO diel patterns.•Diel patterns indicate both anthropogenic and biogenic sources of NO.•Soils contributed a small but significant fraction of atmospheric NOx at both sites.