Chemical and Materials Sciences: Research Findings Vol. 9

Nano-enabled agrochemical delivery is increasingly framed as a route to improve pesticide and fertiliser efficiency while reducing off-target losses, yet the label “precision” often obscures major differences among sustained-release formulations, biologically targeted carriers and truly stimuli-responsive systems. This critical narrative review evaluates how nanocarrier architecture, trigger chemistry, release mechanisms, plant-interface behaviour and soil fate interact to determine whether precision delivery is achieved in agronomically realistic settings. Literature published from 1 January 2012 to 4 July 2026 was examined, with older material retained only when conceptually necessary. The strongest mechanistic evidence concerns pH-, enzyme-, light-, temperature- and ion-responsive systems, including mesoporous silica, biodegradable polymers, metal–organic frameworks, carbon-based materials, hydrogels and hybrid carriers. Across these platforms, apparent gains in loading, protection, adhesion, rainfastness, plant translocation or bioactivity are frequently demonstrated under controlled conditions, but trigger specificity and exposure reduction are less consistently established in field-relevant matrices. A central distinction emerges between controlled release and precision release: slowing diffusion alone does not demonstrate spatial or temporal targeting, and reduced peak exposure can coexist with prolonged environmental persistence. Soil studies further show that carrier–active ingredient interactions can alter sorption, dissipation, mobility and organismal exposure, while aggregation, dissolution, organic matter and ionic composition can change the carrier itself. Evidence for effects on soil microbial communities and non-target organisms remains formulation-specific and too heterogeneous to support general safety claims. The review therefore argues for a design logic based on minimal sufficient complexity, quantitative trigger validation in crop–pest microenvironments, parallel tracking of carrier and cargo, and comparative testing against appropriate conventional formulations. Progress towards credible precision agrochemical delivery will depend less on adding responsive functions than on demonstrating that those functions remain selective, scalable and environmentally interpretable from application through degradation.