Surface plant residues increase the risk of poor stand establishment for corn (Zea mays. L.) and soybean Glycine max (L.) Merr. in no-till. This may result in reduced crop yield and may limit adoption of no-till by farmers. A three- year fieldstudy in an established no-till system with three rotation sequences was conducted to compare the effect of three planter attachments on surface and subsurface residue, and on stand establishment, emergence rate, and yield of corn and soybean. The studywas conducted near Ames, Iowa, on dark-colored soils with corn following-corn, corn-following-soybean, and soybean following-corn rotation sequences. Both corn and soybean were planted with three different attachments placed in front of the planterdouble-disc openers: an offset-bubble coulter a staggered-discs row cleaner, and a powered horizontal-disc row cleaner. The continuous-corn rotation increased subsurface residue only in 1992 and had no effect on surface residue. The continuous-cornrotation, however, did reduce final emerged population, emergence rate, and corn grain yield in some years. In general, there were no significant interactions between rotation sequence and planter attachments. Both row cleaner planter attachments reducedthe amount of surface and subsurface residue in the seed row compared with the offset-bubble coulter attachment. Row cleaner planter attachments also increased final populations of corn in 1990 and soybean in 1991, increased emergence rate indexes ofsoybean in 1991 and of corn in all three years, and had no effects on grain yield. The two row cleaner attachments, however, had fewer barren corn plants in two years. Because row cleaner planter attachments reduce the risk of poor stand establishment inno till, they should improve corn and soybean yield potential and stability in years when stand establishment limits yields.
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