Unlocking the potential of nanoscale sulfur in sustainable agriculture.

The global population is growing rapidly, which poses a significant challenge to food security. Innovation in agricultural technologies is necessary to achieve sustainable development in agriculture and combat food insecurity. Nanotechnology has emerged as a promising tool in agriculture; compared to conventional agricultural chemicals, demonstrated benefits include increased efficiency of delivery and utilization of both nutrients and pesticides, as well as nanoscale-specific stimulation of stress tolerance pathways. Among the many studied nanomaterials, nano-sulfur has demonstrated superior effects at enhancing plant resilience to pathogens and abiotic stresses, as well as improving plant growth and nutritional quality of edible tissues. A number of published studies have investigated the physiological effects (growth promotion, disease resistance) of single or several sulfur and sulfide compounds on crop species. However, there is no systematic analysis of this literature, including the effects and specific mechanisms of various sulfur forms in agricultural applications. In this review, we will discuss the effects of sulfur (including nano-sulfur) on crop species, the underlying mechanisms of action for their transport and transformation in the soil-plant system, and evaluate their suitability in sustainable agricultural development. Additionally, we discuss the current challenges and knowledge gaps for nanoscale sulfur use in agriculture, and describe future research directions to advance our understanding of the sustainable use of this material at the scale of individual fields.