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Abstract Little information is available that evaluates long‐term use of a range of tillage systems and different cropping sequences on poorly drained soils. This study relates corn ( Zea mays L.) growth and yield to several reduced tillage systems used with continuous cropping and a corn‐soybean ( Glycine max L.) rotation. Experiments were conducted on Chalmers silty clay loam (fine‐silty, mixed, mesic Typic Haplaquoll) with 40 g kg −1 organic matter for 12 yr, and Clermont silt loam (fine‐silty, mixed, mesic Typic Ochraqualf) with 10 g kg −1 organic matter for 7 yr. Both soils are nearly level and poorly drained. Tillage systems compared included moldboard plowing, chisel plowing, ridge planting, and no‐till planting. Shallow disking (10 cm) was also included at the Clermont site. On the high organic matter Chalmers soil, continuous no‐till corn was 25 cm shorter at 8 wk, 2% wetter at harvest, and 9.2% lower in yield compared to plowing. Data for chisel and ridge systems were intermediate between plowing and no‐till. No‐till yields were consistently lower than those for plowing after the first 4 yr. When following soybean, no‐till corn was 7 cm shorter at 8 wk, 1% wetter at harvest, and 2.6% lower in yield than corn under moldboard plowing. Corn growth and yield from chisel and ridge treatments were equal to those with plowing when in rotation. On the low organic matter soil in continuous notill corn, plant growth and yields were reduced for the first 3 yr, but were equal or better, compared to plowed corn, for the final 4 yr. In rotation, no‐till corn was equal to plowed corn the first 3 yr and significantly better in 3 of the last 4 yr. Yields with intermediate tillage were similar to plowed yields for continuous and rotational cropping. The relative advantage for no‐till planting with time on the low organic matter soil is attributed to improved soil physical properties.
Griffith et al. (Fri,) studied this question.