Background and Aims <p>Polysaccharide-rich mucilage from plant roots alters soil structure and microbial microhabitats, potentially modifying microbial responses to drying and rewetting.&#xa0;Here we tested the hypotheses that mucilage strengthens soil aggregates, increases microbial survival during dry–rewet cycles, and alters respiration responses to drying and rewetting.</p> Methods <p>To distinguish effects arising from the physical and biophysical properties of mucilage from those due to added carbon, we compared soil amended with 0.1 mg g⁻¹ mucilage with soil receiving the same amount of carbon as glucose. Half of the soils were kept well-watered, while half were dried slowly over 24 days, rewet and monitored for a further 20 days. We adopted an integrative approach linking physical properties (aggregate stability) with microbial responses (PLFA) to mechanistically scale from microbial microhabitats to survival and respiration.</p> Results <p>Mucilage degraded quickly; nevertheless, at minimum water content the extracellular polysaccharide content of mucilage-amended soil was more than twice as large as soils receiving glucose. Wet sieving indicated mucilage amendment and dry-rewet cycle increased aggregate stability. Respiration averaged 12% faster in mucilage-amended than glucose-amended soil.&#xa0;At minimum water content in the dry–rewet treatment, the PLFA pool was 50% larger in mucilage-amended soil, indicating increased microbial survival under water deficit.</p> Conclusion <p>We conclude that mucilage, for example from plant roots, has complex effects on soil that extend beyond that of a physical binding agent and also include significant effects on microbial survivorship and activity across dry-rewet cycles.</p>