Corn and soybean production as affected by tillage systems

Although continuous no-till (NT) cropping systems are appropriate on highly erodible land, concern among producers about potential yield reductions has limited NT adoption in the northern Corn Belt, especially on poorly drained soils. The objectives of this 4-yr study were to quantify the effects of rotational full-width tillage compared with long-term NT and zone-tillage (ZT) systems with and without in-season row cultivation (RC) on corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] yield and economic return. The study was conducted on a tile-drained Nicollet–Webster clay loam soil complex. Sixteen of the 18 treatments comprised a factorial arrangement of three factors: (i) tillage for corn following soybean [NT, 38-cm deep fall ZT, 20-cm deep fall strip-tillage (ST), or spring field cultivate (SFC)], (ii) tillage for soybean following corn [NT or fall chisel plow (CP) plus SFC], and (iii) in-season RC for corn (with or without). Four-year average corn grain yields were greater for ST and ZT (10.1 Mg ha?1) compared with SFC (9.7 Mg ha?1) and NT (9.6 Mg ha?1) tillage for corn. No-tillage for the previous year's soybean crop reduced corn yields in two of 4 yr compared with full width (CP+SFC) tillage. Moreover, when full-width tillage for soybean was rotated with ZT or ST for corn, these treatments produced greater corn yields and economic returns than annual full-width tillage systems. Soybean yields were maximized by rotational tillage; however, the small differences in yields found among the tillage systems did not result in an economic return to full-width tillage practices. When both corn and soybean production was considered, rotational tillage practices were likely to maximize yields but not economic return.