Of all the contaminants that can affect soils, the most common to all anthropogenic activities are heavy metals and metalloids, also called potentially toxic elements, or simply trace elements, because they are present at low concentrations (mg kg−1, or less) in most soils, plants, and living organisms (He et al., 2005; Kabata-Pendias, 2011; Song et al., 2022; Briffa et al., 2020). Despite some controversy about each of these designations (Duffus, 2002; Gustin et al., 2021; Zhang et al., 2022), in the scope of this chapter, we will use the designation heavy metals, as more recently defended by Gustin et al. (2021), specifying the elements of interest whenever necessary. Examples of these are arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), selenium (Se), and zinc (Zn) (Wuana and Okieimen, 2011), a group that also includes As and Se, which are metalloids. In addition to the fact that heavy metals are natural elements in the Earth’s crust, and some are essential for plants and animals, others are non-essential, toxic at low concentrations, and cannot be broken down, i.e. they are nonbiodegradable (He et al., 2005; Kabata-Pendias, 2011; Bolan et al., 2014; Briffa et al., 2020). This characteristic means that, in the remediation of soils contaminated with heavy metals, we often must choose between techniques that allow their immobilization/stabilization in soil, reducing the risk associated with their presence, and techniques that allow the effective removal of these elements from the contaminated environment, extracting them from the soil, and reducing their concentration to acceptable levels, normally below legislated limit values (Kidd et al., 2009; Khalid et al., 2017; Bolan et al., 2014; Zhou et al., 2017; Burges et al., 2018). The latter is usually preferable when considering agricultural soils because of the continued and unacceptable risk of transference of heavy metals to the human food chain (He et al., 2005). This perspective gave rise to a specific phytoremediation technology, non-disruptive soil multifunctionality, that is called phytoextration, where the plants are used to extract heavy metals from the contaminated soil, accumulating them in aboveground plant parts, that can be collected and processed adequately, as contaminated biomass (Kuppens et al., 2015; Robinson et al., 2015), eventually recovering the heavy metals and valorizing the biomass in an adequate manner (Kidd et al., 2009; Wang et al., 2020). Of course, care must be taken to minimize the ingestion of the aboveground plant parts by animals.