Compaction effects on crop yields in Vertisols: Transient under wet years

Abstract Soil compaction commonly impacts productivity in Australian cotton production systems. A field experiment conducted during the 2019–2020 season showed that compaction decreased lint yield by 27%. The objective of this study is to evaluate the legacy effect of soil compaction on subsequent crop yields (wheat [ Triticum aestivum L.] in 2020 and 2022 and cotton [ Gossypium hirsutum L.] in 2021–2022). Wheat and cotton yields, cotton biomass, Verticillium wilt incidence in cotton, soil water, and soil strength were assessed. There was no legacy effect of soil compaction on the wheat grain yields in the 2020 and 2022 seasons. The lack of difference in wheat yields is the result of sufficient rainfall recharging the soil profile during the growing season to overcome compaction limitations of deeper soil water extraction. Similarly, there was no legacy effect of soil compaction on cotton lint yield or fiber quality in the 2021–2022 crop. We found no difference in soil strength (penetrometer resistance) or soil water use by cotton during the 2021–2022 season. These results suggest, indirectly, that cotton root systems were not constrained from extracting water from lower depths of the soil. Verticillium wilt was absent in the compacted plots, and its incidence reached 15.3% in the uncompacted plots during the 2021–2022 season. The legacy effect of soil compaction may not impact subsequent crop yields under the right climatic conditions. However, a study conducted during dry years could offer further insights into its long‐term impact. Future research should be expanded to explore the relationship between disease incidence and soil compaction.