The soil-root nexus: how soil health shapes plant nutrient uptake and food nutritional security

Abstract Soil health constitutes a foundational pillar of agroecosystem functionality, directly governing plant nutrient acquisition, crop productivity, and the nutritional composition of food. This review elucidates the complex interplay among soil physical, chemical, and biological parameters that modulate root architecture, rhizosphere dynamics, and nutrient uptake efficiency, with a particular emphasis on implications for global food security. Soil organic matter (SOM), a widely recognized proxy for soil health, has been empirically demonstrated to augment cation exchange capacity (CEC), enhance soil water retention, and foster microbial biodiversity collectively facilitating nutrient bioavailability and uptake. Quantitative analyses indicate that a 1% increase in SOM can elevate soil water holding capacity by approximately 1.5–2.0 mm per cm of soil depth, thereby promoting root proliferation and physiological nutrient absorption. Crucially, soil microbial consortia including arbuscular mycorrhizal fungi (AMF) and rhizosphere-associated bacteria exert substantial influence over nitrogen mineralization and phosphorus solubilization, thereby modulating nutrient fluxes within the soil–plant continuum. For example, AMF have been reported to enhance phosphorus uptake by 30–50% in Triticum aestivum (wheat) under low-input agroecological systems. However, the persistent degradation of soil health, driven by intensive monoculture practices, synthetic nitrogen overapplication, and widespread erosion, has precipitated significant declines in the micronutrient density of staple crops. Longitudinal studies reveal a 5–40% reduction in critical micronutrients such as Fe and Zn in cereal grains over the past five decades, underscoring the unsustainability of conventional agricultural paradigms. Furthermore, conservation-oriented practices such as no-tillage farming have demonstrated a capacity to enhance soil aggregate stability by 20–40%, thereby intensifying microbial metabolic activity and optimizing root-soil interface dynamics. This review offers a novel perspective by explicitly linking soil health decline with micronutrient depletion and global security risks, framing soil degradation as both an agronomic and geopolitical challenge. In doing so, it integrates soil process research with broader implications for food system resilience and policy, an angle seldom emphasized in prior reviews. As global population projections approach 9.7 billion by 2050, safeguarding soil health emerges as a strategic imperative for sustaining agricultural resilience and ensuring food system stability. This review further contextualizes the degradation of soil resources within the framework of national and global security, highlighting the cascading effects of food system fragility, malnutrition, and geopolitical tensions stemming from resource scarcity. Through a comprehensive synthesis of recent empirical advancements, this work underscores the exigency of adopting sustainable soil management strategies aimed at mitigating nutrient depletion, preserving ecosystem services, and fortifying the resilience of global food systems. Graphical Abstract