Natural Mineral Enrichment in Solanum tuberosum L. cv. Agria: Accumulation of Ca and Interaction with Other Nutrients by XRF Analysis

Calcium is a crucial nutrient for bone development and the normal functioning of the circulatory system, whereas its deficiency can trigger the development of osteoporosis and rickets. On the other hand, Solanum tuberosum L. is one of the most important staple food crops worldwide and is a primary component of the human diet. Accordingly, using this staple food, this study aims to develop a technical itinerary for Ca biofortification of cv. Agria. As such, an itinerary of Ca biofortification was promoted throughout the respective production cycle. Seven foliar sprays with CaCl2 or chelated calcium (Ca EDTA) were used at concentrations of 12 and 24 kg ha−1. The index of Ca biofortification and the related interactions with other chemical elements in the tuber were assessed. It was found that, relative to the control at harvest, Ca content increased 1.07–2.22 fold (maximum levels were obtained with 12 kg ha−1 Ca-EDTA). Ca(EDTA) at a concentration of 24 kg ha−1 showed the second-highest levels in Ca, S and, P content. By adding CaCl2, it was also possible to identify a tendency of increasing contents (in Ca, K, S, and P) when the spraying concentration increased (12 kg ha−1 to 24 kg ha−1). Outside of the Ca higher content, dry weight, height, diameter, and the colorimetric parameter L of the tubers did not vary significantly, but minor changes occurred in the colorimetric parameters Chroma and Hue. It was concluded that Ca(EDTA) could trigger a more efficient Ca biofortification of Agria potato tubers with the additional enrichment of K, S, and P.