Biological Science: Research Developments and Innovations Vol. 3

Climate change is increasing the frequency and intensity of drought, heat, salinity and other constraints that destabilise crop production while pressures to reduce fertiliser and pesticide dependence continue to grow. The plant–soil microbiome is therefore being considered not only as a source of beneficial microorganisms but as an engineerable ecological component of crop systems. This critical narrative review evaluates the evidence for manipulating root- and soil-associated microbial communities to improve crop performance under climate change. Literature published from 2010 to 4 July 2026 was examined through agriculture, biomedical and multidisciplinary scholarly sources, with foundational earlier work retained when conceptually necessary. The synthesis distinguishes six intervention classes: direct microbial inoculation, synthetic microbial communities, host-mediated community selection, microbiome-informed crop breeding, rhizosphere and root-exudate engineering, and management-based manipulation of resident communities. Evidence is strongest for the capacity of plant genotype, root chemistry, soil properties and stress history to alter microbiome assembly, and for microbial contributions to nutrient acquisition, mineral homeostasis, disease suppression and some forms of drought or salinity tolerance. Yet the agronomic predictability of microbiome interventions remains substantially lower than  their mechanistic plausibility. Controlled-environment studies often overestimate field portability because introduced organisms encounter resident-community resistance, heterogeneous soil chemistry, climatic variability, dispersal limitation and host developmental effects. Meta-analyses support average benefits of some biofertilisers and arbuscular mycorrhizal fungi, but also reveal strong context dependence; recent evidence questioning commercial inoculant performance reinforces the need to treat efficacy as conditional rather than intrinsic. A credible engineering framework should therefore optimise ecological fit, functional redundancy, colonisation, persistence and recoverability rather than maximise community complexity. Progress requires multi-environment field trials, absolute and functional microbiome measurements, explicit testing under compound climate stresses, and safety assessment of ecological legacies. Microbiome engineering is best viewed as a complementary component of climate-resilient agronomy whose value will depend on reliable host–microbe–soil matching and evidence of durable field-scale benefit.