Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 1997
Publication Date: N/A
Interpretive Summary: No-till systems have more residues on the surface than tilled systems. These surface residues protect the soil surface from erosion, but they also increase the risk of poor stand establishment for corn and soybean in no-till. Residues slow emergence and reduce final stand by interfering with planter performance and shading the soil and thus, slow warming by the sun. Poor stand establishment may result in reduced crop yield, and it has been blamed for the slow adoption of no till by farmers. A 3-year field study was conducted to determine whether stand establishment could be improved in no till by moving residues from the seed row at planting with planter attachments. Both corn and soybean were planted with three different attachments placed in front of the planter double-disc openers; an offset-bubble coulter, a staggered-discs row cleaner, and a powered horizontal disc row cleaner. The powered horizontal disc row-cleaner planter attachment and the staggered discs row-cleaner attachment were more effective at moving residue from the seed row than the offset-bubble coulter attachment. Both row-cleaner attachments increased final emerged population and emergence rate of both corn and soybean in some years compared with the offset-bubble coulter attachment. Corn and soybean grain yield was not increased by residue clearing planter attachments in this study with overplanting and thinning, but improved stand establishment in no till should improve corn and soybean yield potential and stability in years when cold soil limits emergence, stand establishment, and early growth. The possible impact of this research is that through the use of planter attachments farmers will have better stand establishment in no till and this should increase the no-till adoption rate.
Technical Abstract: Surface plant residues increase the risk of poor stand establishment for corn and soybean in no-till. A 3-year field study in a no-till system with three rotations 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 study was conducted near Ames, IA, on dark-colored till soils with corn-following-corn, corn-following-soybean, and soybean-following-corn rotations. Both corn and soybean were planted with three different planter attachments; an offset-bubble coulter, a staggered-discs row cleaner, and a powered horizontal disc row cleaner. Soil cores were taken immediately after planting to measure the amount of surface and subsurface residues in the seed row. The continuous-corn rotation increased subsurface residue only in 1992 and had no effect on surface residue. The continuous-corn rotation, 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 reduced the 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 of soybean 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. Row cleaner planter attachments should improve corn and soybean yield potential and stability in years when stand establishment limits yields.