Research Article Received: 11 May 2021 Revised: 2 May 2022 Accepted article published: 22 May 2022 Published online in Wiley Online Library: 9 June 2022 (wileyonlinelibrary.com) DOI 10.1002/jsfa.12026 Use of compost in the uptake mitigation of arsenic in Beta vulgaris L. var. cicla Silvia Rita Stazi, a Enrica Allevato, a Rosita Marabottini, b Leonardo Digiesi, b Andrea Vannini b and Gabriele Chilosi b * Abstract Background: Arsenic (As) may represent a risk for crop yield quality and human health since it may accumulate in the edible plant organs with the potential of leading to acute or chronic toxic effects in varied segments of the population. Management of soil fertility through compost has proven to be a valuable practice for increasing and maintaining soil organic matter, with nutritional benefits for crops. This work aimed to evaluate Swiss chard yield and the change in the bioavailability, bioaccumu- lation, and partitioning of As in the response of the use of compost or conventional mineral fertilization in an open-field trial conducted in a volcanic area in central Italy characterized by the natural contamination of As in soil. Results: Compost treatment led to a short-term increase trend in soil organic carbon, total nitrogen, and available phosphorus in a significant way. In the compost-amended plots, the mitigation of the As uptake was detected in leaves, which are the edible part of Swiss chard. The As bioaccumulation factor in leaves of Swiss chard and the translocation factor for leaves/roots were also decreased using compost. Conclusion: Fertilization by compost can improve soil fertility, sustain Swiss chard production, and mitigate As accumulation in leaves of this crop grown in a naturally As-contaminated soil. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Keywords: arsenic uptake; bioaccumulation factor; bioavailability; food safety; translocation factor INTRODUCTION Plants can absorb non-essential elements from contaminated soils depending on their bioavailability as a consequence of the chemical nature and concentration of the elements, soil chemical–physical properties, presence of other ions in the soil, and plant species. 1,2 Among non-essential elements, arsenic (As) represents a risk for crop yield quality and human health, since it may accumulate in the edible plant organs with the poten- tial of leading to acute or chronic toxic effects in varied segments of the population. 3,4 Inorganic As has been classified as a group 1 carcinogenic substance by the International Agency for Research on Cancer. 5 The As concentration rarely exceeds 10 mg kg -1 in uncontaminated soils, but in contaminated soils the inorganic As can reach high concentrations, above 50.0 mg kg -1 . 6,7 Based on the risk to human health, the European Commission has intro- duced maximum allowable levels of inorganic As in rice and rice products. 8 The European Food Safety Authority's (EFSA's) scien- tific report on the evaluation of the complete diet showed that the average exposure to inorganic As is below the reference range. However, EFSA recommends that various foods be moni- tored to assess dietary exposure to inorganic As. 9-11 Exposure to As may be associated with the consumption of different food crops, such as leafy vegetables, which can adsorb As from con- taminated soil and accumulate it in their edible parts. 12-15 Swiss chard (Beta vulgaris subsp. cicla) is an important horticul- tural crop distributed worldwide. In Italy, this crop is cultivated in both greenhouses and open fields, covering approximately an annual average of 5500 ha 16 and generating an important income for farmers. Swiss chard is considered one of the healthiest vege- tables because it contains a large number of nutraceuticals, such as minerals, vitamins, and phytochemicals. 17,18 Despite these excellent nutraceutical characteristics, Swiss chard is prone to accumulate heavy metals when grown in contaminated soils. In a field study in Spain, Peris et al. 19 reported contents of cadmium and lead in edible parts of lettuce and Swiss chard cultivated in contaminated soil were higher than their tolerance limits in crops. A high accumulation of heavy metals was found in Swiss chard grown in two sites in Ethiopia irrigated with polluted water. 20 Data from research conducted in the Basque Country (Spain) to * Correspondence to: G Chilosi, Department for Innovation in Biological, Agro- food and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy. E-mail: chilosi@unitus.it a Department of Chemical, Pharmaceutical and Agricultural Science (DOCPAS), University of Ferrara, Ferrara, Italy b Department for Innovation in Biological, Agrofood and Forest systems (DIBAF), University of Tuscia, Viterbo, Italy © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 6596