Alteration in surface energy balance fluxes induced from long-term disk-tilled versus no-till management in maize production

Impacts of tillage-induced surface conditions on modification of the soil-crop-atmospheric interface have not been adequately studied. There is poor quantitative understanding at the intersection of tillage and surface energy balance (SEB), especially for the complete growing season. This research measured and evaluated SEB fluxes, i.e., net radiation (R_n), latent heat (LE), sensible heat (H), and ground heat flux (G) for three growing seasons (2011–2013) in a concurrent fashion in two similarly-managed maize (Zea mays L.) fields, which were under disk-till (DT) and no-till (NT) management for 17 years. To this end, each field was equipped with an identical Bowen Ratio Energy Balance System (BREBS) that collected 30-minute SEB data throughout the growing season. G was the most impacted SEB component, followed by H, LE, and R_n on an average basis, although these comparisons were subject to change during different times in the growing season. Seasonal mean interpretations masked within-season heterogeneity in DT vs. NT SEB dynamics and thus, daily differences for all SEB components, albedo (α), surface soil moisture (θ_v), and Bowen Ratio (β) were quantified. Greater α in NT field (0.16) was maintained throughout the growing season than DT field (0.14). All SEB components demonstrated greater differences between DT and NT in the early and late growing season. Nevertheless, SEB observations show that tillage impacts during significant crop canopy cover should not be ignored. NT surface (0–0.30 m) θ_v was as much as 22% greater than that of DT, and held critical importance for regional NT crop production during the extreme 2012 drought. θ_v also exerted control on albedo, with wetter soils having a lower albedo, which consequently translated into altered R_n across DT and NT fields. The research findings shown here underscore the particular importance of accounting for within-season behavior of albedo and G along with other components of SEB for evaluating soil management-related applications.