GLOBAL ANALYSIS OF THE POTENTIAL FOR N2O PRODUCTION IN NATURAL SOILS

A simple global model of the production potential of nitrous oxide (N2 O) in natural soils is developed to analyze the relative importance, b oth geographically and seasonally, of the different controls on N2O pr oduction at the global scale. Five major controls on N2O production ar e included: (1) input of organic matter, (2) soil fertility, (3) soil moisture status, (4) temperature, and (5) soil oxygen status. Indices for the controls are derived form global gridded (1-degrees x 1-degree s resolution) data bases of soil type, soil texture, NDVI and climate. The model explains close to 60% of the variability found in measureme nts reported at about 30 sites in six different ecosystems throughout the world. Although this result is reasonable for global analyses, the correlation is considered insufficient to make global estimates of ni trous oxide emission with confidence. The model confirms conclusions f rom earlier studies that the major source regions of nitrous oxide are in the tropics.