Agricultural Soil Science in a Changing Climate: Soil Health, Carbon Cycling, Nutrient Dynamics and Agroecosystem Resilience

Crop genetic diversity is widely presented as the raw material for adapting agriculture to a warming and more variable climate, yet the pathway from conserved diversity to adapted cultivars remains poorly characterised and unevenly evidenced. This critical narrative review examines four components of that pathway, namely ex situ and in situ conservation of plant genetic resources, the mobilisation of crop wild relatives and landraces, the construction and use of pangenomes, and the application of precision breeding technologies. Literature was identified through open scholarly databases and indexes, supplemented by citation searching and by examination of authoritative institutional documents, with verification of bibliographic identity and of the correspondence between each source and the claim it supports. The synthesis indicates that the evidence base is strongly asymmetric. Conservation gap analyses, genebank genotyping and pangenome assembly are methodologically mature and internally consistent, whereas evidence that these resources have produced climate-adapted cultivars at scale is sparse, concentrated in qualitative disease resistance traits, and rarely accompanied by multi-environment yield data. Structural variation captured by graph pangenomes recovers heritability that single-reference analyses miss, but the demonstrated breeding applications remain concentrated in a small number of well-resourced crops. Genome editing has delivered convincing qualitative phenotypes and a smaller number of field-validated quantitative gains, while paralogue redundancy and background dependence limit the transfer of edited alleles between species. The central unresolved problem is not the discovery of adaptive variation but its conversion into varieties that farmers grow, which depends on prebreeding capacity, multi-environment phenotyping, seed systems and varietal turnover rather than on sequencing throughput. Governance of digital sequence information and divergent national regulation of precision-bred plants add further uncertainty. Priorities include environment-resolved phenotyping of genebank material, validation of genomic vulnerability predictions against measured fitness, and reporting standards that make pangenome-based claims comparable across crops.