Tillage and Rotation Interactions for Corn and Soybean Grain Yield as Affected by Precipitation and Air Temperature

rotation is also more effective in preventing deep leaching of nitrate N than continuous corn (Katupitiya et al., Reduced tillage, including no-till, and crop rotation are common 1997; Varvel and Peterson, 1990). Reduced stress from practices for corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] production in the Midwest. Benefits of no-till vary with latitude pests may be one of the reasons for improved yield with and cropping system. This study was conducted to evaluate the influcrop rotations (Boosalis and Doupnik, 1976). ence of seasonal temperature and precipitation on the effects of priReports on the effects of tillage and crop sequence mary tillage (plow, disk, chisel, subsoil, ridge-till, and no-till) and (rotation) on grain yield of both corn and soybean in the rotated and continuous corn and soybean production under rainfed Corn Belt vary considerably. Planting corn and soybean conditions over 16 yr in southeastern Nebraska. Corn and soybean without tillage results in increased yield in some enviproduced less grain with greater summer temperatures. Corn yield ronments but less in other environments. Several reincreased with less spring and more summer rainfall. Tillage and searchers have shown that the crop rotation benefit is rotation practices affected corn grain yield; but only rotation affected greater with no-till than with tillage (Griffith et al., 1988; soybean yield. Corn produced less grain with no-till than with plow. Lund et al., 1993). The summary statement that yield The tillage year interaction was significant for both crops; the yield advantage for plow was less during seasons with warmer springs. increase with no-till compared with tillage is less likely Soybean grain yield was less responsive to favorable environments for continuous corn compared with corn in rotation on with the chisel than other tillage treatments. Grain yield was greater poorly drained soils in northern latitudes is supported with rotation than continuous cropping for both corn (7.10 vs. 5.83 by results of tillage studies conducted on both poorly Mg ha 1) and soybean (2.57 vs. 2.35 Mg ha 1). The benefit of rotation and well-drained soils in Ohio (Dick et al., 1991) and in terms of grain yield was greatest for corn during years with cool on poorly drained soils in Illinois (McIsaac et al., 1990) springs. The benefit of rotation for soybean grain yield did not vary and Iowa (Brown et al., 1989). with weather conditions. Seasonal temperature and rainfall patterns On well-drained soils, crop yields were less with noinfluenced the effects of tillage and rotation on corn yield. In contrast, till than with tillage in studies conducted in Iowa (Chase for soybean, only the pattern of temperature influenced the effect of and Duffy, 1991), Indiana (West et al., 1996), northwesttillage on yield. ern Iowa (Bakhsh et al., 2000), and Wisconsin (Adee et al., 1994; Lund et al., 1993). In contrast, yields were greater with no-till in Nebraska (Dickey et al., 1994) N and ridge-till planting are established conand Ohio (Dick et al., 1991). To further complicate the servation tillage systems in the Midwest. The area issue, no differences in yield between no-till and tilled planted without preplant tillage in the United States is treatments were reported for studies conducted in Michestimated to be 21 106 ha yr 1 (38% of U.S. cropland; igan (Hesterman et al., 1988) and Wisconsin (Al-Darby Conserv. Technol. Inf. Cent., 2000). The primary reason and Lowery, 1986; Lund et al., 1993). Corn and/or soygiven by crop producers in Nebraska for practicing conbean yield was greater with ridge-till than with no-till in servation tillage is reduced costs (McCabe, 2002). Other Indiana (West et al., 1996) but not different in Nebraska important reasons given for adopting conservation till(Cahoon et al., 1999) and Wisconsin (Al-Darby and Lowage were soil protection, water conservation, increased ery, 1986). Griffith and Wollenhaupt (1994) summarized yield, and increased profit. these differing results by stating that the probability of Rotation of corn and soybean is often preferred to a corn yield increase with no-till is greatest on wellcontinuous cropping with either crop because the rotadrained soil when grown in rotation and in southern latition produces greater grain yield of both crops (Petertudes of the United States. The objective of this research son and Varvel, 1989a, 1989b; Varvel, 1994; West et al., is to evaluate the influence of seasonal temperature and 1996). Input costs are often less with rotation (Foltz et al., precipitation on tillage and crop sequence (rotation) 1995), with less N fertilizer needed for the corn–soybean effects on the grain yield responses in corn and soyrotation compared with continuous corn. A corn–soybean bean production. W.W. Wilhelm, USDA-ARS, 117 Keim Hall, Univ. of Nebraska, Lincoln, NE 68583-0934; and C.S. Wortmann, Dep. of Agron. and MATERIALS AND METHODS Hortic., Univ. of Nebraska, Lincoln, NE 68583-0915. Joint contribuThis field research was conducted at the Rogers Memorial tion the USDA-ARS and the Univ. of Nebraska, Agric. Res. Div., Lincoln, NE 68583, Journal Series no. 13950. Product names are given Farm over 16 yr (1986–2001) on a silty clay loam soil (deep, solely for the benefit of the reader and are not meant to constitute a moderately well-drained upland Sharpsburg soil formed in recommendation or warranty by USDA’s Agricultural Research Service loess; fine, smectitic, mesic Typic Argiudolls) near Lincoln, or the Agricultural Research Division of the University of Nebraska. NE, under natural rainfall conditions. Received 11 Dec. 2002. *Corresponding author ([email protected]). The experiment was designed as a randomized complete block (six blocks) with a split-plot arrangement of treatments. Published in Agron. J. 96:425–432 (2004). Tillage treatments were assigned to whole plots and included  American Society of Agronomy 677 S. Segoe Rd., Madison, WI 53711 USA chisel plow (chisel), tandom disk (disk), moldboard plow (plow),