Winter wheat grain yield stability under different tillage practices

Authors: AULA, LAWRENCE - University Of Nebraska; Mikha, Maysoon; EASTERLY, AMANDA - University Of Nebraska; CREECH, CODY - University Of Nebraska

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2022
Publication Date: 10/20/2022
Citation: Aula, L., Mikha, M.M., Easterly, A.C., Creech, C.F. 2022. Winter wheat grain yield stability under different tillage practices. Agronomy Journal. 115(2):1006-1014. https://doi.org/10.1002/agj2.21236.
DOI: https://doi.org/10.1002/agj2.21236

Interpretive Summary: Tillage has been critical to enhance land productivity in agricultural production systems. Over the centuries, tillage and herbicides have evolved together; herbicide use allows many new forms of tillage, such as no-tillage (NT), strip, ridge, stubble mulch (SM), reduced, and/or minimum tillage. For each tillage practice, grain yield stability must be evaluated in dryland systems with data from long-term experiments. A tillage practice that produces more stable yield across diverse range of environments (precipitation and ambient temperature) could be more advantageous than any tillage practice with a high yield only under specific environment. Yield stability is defined as the plant's ability to survive and produce with less variable yield over a range of environmental conditions. We evaluated long-term (39 years) winter wheat grain yield stability under no-tillage (NT), stubble mulch (SM), and moldboard plow (MP) tillage practices. The experiment was established as a winter wheat-fallow under dryland cropping system located at the High Plains Agricultural Laboratory (HPAL), Sidney, Nebraska (NE). We found significant grain yield stability was achieved with SM while grain yield stability with NT and MP was achieved under specific environmental conditions. In general, using minimum tillage, such as SM, that maintains residues on the soil surface could contribute to yield resiliency across different environmental conditions and enhance land sustainability in dryland cropping systems.

Technical Abstract: Grain yield stability is vital for achieving yield consistency across a broad range of environments. The significance of this is well documented in crop genetic studies and may equally be relevant for tillage practices used in croplands. The objective of this study was to evaluate long-term winter wheat (Triticum aestivum L.) grain yield stability under different tillage practices. The study was designed as a randomized complete block with three replications. The independent variable was tillage with three levels, that is, no-tillage (NT), stubble mulch (SM), and moldboard plow (MP). The experiment was established as a winter wheat-fallow under a dryland cropping system. Each phase of the wheat-fallow was present each year. The historical grain yield data from 1972 to 2010 were presented in this study. Yield stability was assessed using regression coefficients (ßi) and squared deviation from regression (S2d). Grain yield had average stability since each tillage practice had a ßi of 1.0. The SM tillage had an S2d of 0.03 (P = 0.90) which was not significant than zero (0) while NT and MP had an S2d of 0.06 (P = 0.04) and 0.07 (P = 0.01), respectively, that were significant than zero (0). This suggests that SM had more stable yield under different environments when compared to NT and MP. In general, using minimum tillage such as SM that maintains residues on the soil surface could contribute to yield resiliency across different environments and enhance land sustainability in dryland cropping systems.