Seasonal variability in emission of nitrous oxide from soil

Abstract

Seasonal variability in emission of nitrous oxide (N2O) from soil was studied by monitoring N2O emissions from six Iowa soils for 12 months (mid‐April, 1979 to mid‐April, 1980). The soils studied were representative of soils used extensively for corn and soybean production in north‐central Iowa. They had been planted to soybeans and had received no N fertilization. The amounts of N2O‐N evolved from these soils in 12 months ranged from 0.34 to 1.97 kg ha−1 and averaged 1.20 kg ha−1. A substantial proportion (average, 67%) of the N2O evolved in 12 months was produced during the summer months of the study period, whereas only a small proportion (average, 2%) was produced during the winter months. The corresponding proportions for the spring and fall months were 18% and 13%, respectively. Copyright 1980 by the American Geophysical Union.