Can hairy vetch cover crop affects arsenic accumulation in vegetable crops?

Abstract

Agricultural practices greatly influence the bioavailability of heavy metals. Arsenic (As) is a heavy metal identified as a concern due to its potential impact on human health. Two-year field experiments were performed to evaluate the effect of cropping system on As accumulation in tomato, sweet pepper and zucchini. The treatments were: (i) conventional system based on common practices of the area; and (ii) alternative systems based on cultivation of hairy vetch (Vicia villosa Roth.) in no-tillage before vegetable crops. Randomized block design with three replications was adopted. Soil and plant samples (fruits, leaves, stems and roots) were collected at crop harvesting. Plant samples were weighed and analyzed to evaluate As content. Soil chemical analyses were performed to evaluate the total organic carbon and nitrogen content. The As accumulation observed in plant samples of tomato, sweet pepper and zucchini resulted always low in the alternative system, except in fruits where As accumulation was similar between the systems. The increase of soil organic matter observed in alternative system probably caused a reduction of As accumulation into crop tissues. Therefore, hairy vetch cultivation in no-tillage could be a suitable strategy to reduce the As uptake of vegetable crops in geogenic contaminated soils.