Tillage practices alter the surface energy balance - A review

Tillage is commonly implemented worldwide to improve crop productivity by optimizing soil temperature and moisture, reducing penetration resistance of the seedbed, and suppressing weeds. However, these benefits are accompanied by drawbacks, including increased erosion and loss of soil organic matter. Research continues on how to maximize benefits and minimize drawbacks of tillage in a range of agricultural systems. The surface energy balance (SEB) may be a promising avenue for future tillage research because it describes the partitioning of energy into compartments crucial to crop productivity, especially heating the soil and evaporating water. Despite this relevance, very little research addresses the effects of tillage on the SEB, and the existing literature does not adequately describe the relationship between these two topics. The aims of this review are to identify research that has been completed on the subject, synthesize current knowledge, and propose topics for continuing research. This review suggests that alterations to soil surface cover, surface roughness, and near-surface porosity caused by tillage are reflected in changes in the SEB, with the greatest effects evident during wetting-drying cycles. The total available energy is increased following tillage, but the magnitude of change and partitioning of that energy is not understood, which directly relates to the energy available for heating the soil and evaporating water. Future research should focus on quantifying the magnitude of effects of tillage on the SEB, how those effects change over time, and identifying any other indirect effects that may inform better management decisions.