Agronomic biofortification with magnesium nanofertilizer and its effect on the nutritional quality of beans

Crop quality has been compromised due to nutrient deficiencies. The macronutrient magnesium (Mg) is essential; however, it has not been considered in agronomic fertilization programs, affecting human health. The objective of the study was to increase the Mg content in the fruits of green beans cv. 'Strike' by applying Mg-nanofertilizer, as well as evaluating its effect on growth, performance and nutritional quality, versus magnesium sulfate (MgSO4). The experiment was carried out under shade mesh conditions in Delicias, Chihuahua, Mexico during the period August-October 2022. A completely randomized experimental design was used, with two Mg sources: Mg nanofertilizer (NanoMg) and MgSO4 at doses of 50, 100 and 200 ppm and a control without application, forming seven treatments with six repetitions each. The results indicate that the maximum yield was provided by NanoMg and MgSO4 at 200 ppm, with values greater than 300%. The Mg distribution pattern for the NanoMg treatments presented the following concentration order: root>leaf>stem>fruit; while, for the MgSO4 treatments it was: leaf>root>stem>fruit. The most efficient treatment in increasing the Mg content in the fruit was NanoMg at 200 ppm, which achieved a biofortification of more than 120% with respect to the control. Therefore, when consuming 100 g of green beans cv. 'Strike' biofortified by NanoMg, the recommended daily needs of the human being could be satisfied. Finally, it is concluded that nanofertilizers are the best option for a biofortification program since they offer a sustainable alternative by increasing productivity and quality in green bean fruits.