Fig. 1. Tillage and crop rotation impact on soybean grain yield, protein concentration, and oil concentration averaged across 2003, 2004, and 2005 growing seasons in Arlington, WI. Rotations are: 1 = first-year soybean following 5 yr of corn; S-C = soybean alternated annually with corn; 2, 3, 4, and 5 = second-, third-, fourth-, and fifth-year soybean following 5 yr of corn; and Cont. = continuous soybean since 1983. Least significant difference (LSD) values for the tillage by rotation interaction at P 0.05; NS = not significant; C. till = conventional tillage.