Nitric oxide soil emissions from tilled and untilled cornfields

Results from the eddy covariance nitric oxide flux measurements made at a site on the Eastern Shore of Maryland during July 25-30, 1995 are reported. The mean (and median) NO flux measured along the dividing line between two fertilized cornfields, one conventionally-tilled and one untilled, was 7.5 (and 7.6) ng N m(-2) s(-1). Average NO emission rates from the untilled field, 1.2 (0.1-3.3) ng N m(-2) s(-1), were significantly lower than from the tilled field, 8.6 (2.5-15.5) ng N m(-2) s(-1), where the ranges in parentheses cover the central 90% of the data. This finding suggests that no-till agriculture might reduce NO emission from soils during the summer months. (C) 1998 Elsevier Science B.V.