Fig. 1. Relation of (a) relative beet yield, (b) relative sucrose yield, and (c) relative adjusted beet yield to preplant soil NO3–N. Tile-drained soils with high risk of leaching (furrow irrigation or winter rain higher than 470 mm—80% of the annual mean precipitation in the studied area) and rainfed locations in drought years (less than 350 mm year–1—less than 170 mm during spring) are excluded.