This chapter discusses the multifaceted role of crop residues in sustainable agriculture. It outlines how residues represent a substantial portion of annual phytomass harvested globally and can be perceived either as a nuisance or as a valuable resource. Residue management influences plant nutrient availability, soil structure, hydrology, organic matter dynamics, greenhouse gas emissions and surface albedo. Leaving residues on fields enhances soil health by reducing erosion, retaining moisture, improving nutrient cycling and increasing soil carbon content. However, competing demands for crop residues including other uses such as cooking, building materials, bioenergy, animal feed and bedding pose a challenge for Conservation Agriculture and require site-specific assessments of the optimal amount to be sustainably removed from fields. A case study illustrates the potential of crop residue mulching to sequester soil carbon, comparing modelled rates with literature values and highlights the complexities involved in managing residues for optimal environmental and agronomic outcomes.