The purpose of this paper is to study the effect of row structures on backscattering by soil surface. A new modelling of periodic row structures is proposed. The Moment method is used to evaluate the effect of rows on backscattering. To check theoretical results, a campaign carried out in the north of France in 1994 is used. Series of radar measurements were made by two radars, ERASME and RENE in S band (3.25 GHz), C band (5.6 GHz), and X band (9.25 GHz). It is shown, that the effect of row structure on radar measurements is sensitive to radar frequency and decreases with increasing incidence angle. Finally, the slope of the graph of radar measurements versus incidence angles seems to be a useful tool to retrieve the radar look direction perpendicular or parallel to rows.