Soil heterotrophic respiration after irrigation retirement is differentially influenced by moisture and substrate availability over time

Water limitations are forcing producers to transition large areas of currently irrigated farmland into dryland agriculture across the Western U.S. with unclear effects on global soil carbon (C) dynamics. An experiment established in 2017 in a no-till, maize system in Colorado suggested that soil heterotrophic respiration (Rh) following irrigation retirement was co-regulated by water and available C. We continued Rh measurements in 2021–2022 along with monthly soil samplings to explore the intera