Importance of nanofertilizers in fruit nutrition

The use of mineral elements applied through conventional or organic fertilizers is one of the pillars of food production. However, various edaphic and climatic factors reduce the bioavailability of the elements applied, leading to the soil, water, and atmosphere contamination, as well as economic losses and a potential decrease in the productivity of crops. Individual and comprehensive improvement of fertilizer bioavailability has been linked to different techniques in agricultural practice. Among them is the use of nanofertilizers, as an alternative with great potential, which still requires further investigation regarding several types of materials and its environmental impact. This chapter aims to present a review of the results and perspectives on the use of nanoparticles (NPs) and nanomaterials (NMs) in the nutrition of fruit crops. The nanofertilizers whose use has been reported in fruit crops can be categorized, from a functional point of view, as nanofertilizers for direct application to the soil, with irrigation, or by foliar route. Examples of these are NPs of ZnO, Zn, Fe, CuO, Cu, etc. Another category of nanofertilizers is made up of nanoporous materials, nanoclays, and nanoforms of polysaccharides as chitosan that function as vehicles with a large surface area that allows the adsorption and stabilization of the chemical elements applied as ions or nanoparticles to the plants. In either case, the use of nanofertilizers can potentially (i) improve the bioavailability of nutrients, especially in marginal soils; (ii) decrease the excessive application of nutrients in crops, especially metals; and (iii) mitigate the susceptibility to environmental stress through a biostimulant effect. The chapter ends with a section on the environmental destination and the potential trophic transfer of NPs and NMs.