An explanatory model that relates laboratory measurements of nitric oxide (NO) production in soil to field measurements of the diffusive flux of NO from the same soil to the atmosphere is presented. Microbial NO production in soils is represented by a production term independent of, and an uptake term with first-order dependence on, NO concentration. These production and first-order uptake terms can be measured in flow-through soil columns. Within the model, representing a field soil, the divergence in vertical diffusive flux of NO is represented by the production minus uptake and so a flux to the atmosphere is calculated. At Kjettslinge, Sweden, a field flux of NO of 2--17¿10-9 g N m-2 s-1 was observed under aerobic conditions, while laboratory measurements and the model give a calculated flux of NO for the same soil under the same environmental conditions of 3--11¿10-9 g N m-2 s-1. Thus the results suggest that laboratory measurements on a specific soil may be used to determine the field flux from the same soil under certain well specified conditions. ¿ American Geophysical Union 1989