Sixty years of crop diversification with perennials improves yields more than no-tillage in Ohio grain cropping systems

Context Diversifying crops and reducing tillage can enhance the
environmental health of agroecosystems, consequently improving crop
performance over time. We report data from the Triplett-Van Doren
No-Tillage and Crop Rotation Experiment, one of the longest-running
replicated agricultural experiments in the United States, to evaluate the
impact of no-tillage and crop rotation on corn and soybean yields over six
decades. Objective To assess the long-term impact of crop rotation on crop
performance in Ohio agricultural systems, and how these rotations interact
with tillage practices. Methods This study was conducted at two sites with
contrasting soil characteristics: Wooster (well-drained silt-loam) and
Hoytville (poorly drained clay-loam). The experiment was a two-way full
factorial design with three levels of tillage (Moldboard, Chisel, and
No-Tillage) and three crop rotations (Continuous-Corn, a two-year
Corn-Soybean rotation, and a three-year Corn-Forage-Forage rotation).
Results Crop rotation was the main driver of long-term crop performance,
with the most favorable responses observed when forage crops were included
in the cropping system at both sites. Over 60 years of field data showed
corn yield increases ranging from 12 % to 21 % when transitioning from
Continuous-Corn to Corn-Forage-Forage rotation in Wooster and Hoytville.
Crop responses to tillage varied by soil type. In the well-drained
silt-loam soil of Wooster, no-tillage led to immediate positive responses
in all crop rotation systems. However, in the poorly drained clay-loam
soil of Hoytville, significant initial yield penalties of up to 20 % were
observed for No-Tillage Continuous-Corn. These initial yield reductions
were mitigated when soybean or forage crops were included in the system.
Corn yields under No-Tillage increased between 6 % and 16 % in Wooster,
with no significant change for Hoytville. Soybean yields under no-tillage
increased by up to 15 % in Wooster and 4 % in Hoytville compared to
Moldboard systems. Crop responses varied under extreme precipitation. In
Wooster, corn rotated with forage, outperformed continuous corn in dry
conditions, especially under no-tillage. In Hoytville, corn-forage
rotations yielded highest under wet conditions, regardless of tillage.
Conclusions Based on data spanning over 60 years of crop rotation and
no-tillage practices in Ohio, rotations including perennial crops
consistently showed significantly increased yields compared to monoculture
corn and corn rotated with soybean, regardless of the tillage system.
Furthermore, yield reductions associated with the transition to no-tillage
were mitigated when forage crops were integrated into the cropping system.
Implications By evaluating long-term trends, we found that no-tillage can
be viable even in clay soils under temperate climates when perennial crops
are included in the rotation system. Our results demonstrate that
long-term crop yields can significantly benefit from the implementation of
both practices adopted together in cropping systems.