Fig. 4. Residual soil NO₃ concentration vs. depth for each N treatment after harvest in 2002 through 2005. The N treatments for corn were H = 199 kg ha^–1, M = 138 kg ha^–1, L = 69 kg ha^–1, and R = 69 kg ha^–1 of N applied at V1 to V3 with another 69 kg ha^–1 N side-dressed at midseason (V16). No N fertilizer was applied to soybean. Corn was harvested in even years, soybean in odd years. Horizontal bars, where present, represent least significant difference where an F test was significant ( = 0.05).