An on-farm field trial was conducted to investigate the feasibility of applying commonly used soil amendments to reduce the accumulation of arsenic (As), cadmium (Cd), and lead (Pb) in sweetpotato (Ipomoea batatas L.) storage roots. The cultivar ‘Beauregard’ was grown in an organically managed field with natural As, Cd, and Pb levels. The following soil amendments were applied: agricultural lime (AGL) (1 t·ac−1), gypsum (GYP) (1 t·ac−1), biochar (BIO) (1 t·ac−1), and silicon provided as wollastonite (WOL) (2.5 t·ac−1). Agricultural lime and WOL increased soil pH and calcium levels, ranging from 14% to 25% and 16% to 90%, respectively. Soil amendments were not associated with storage root yield variation. Wollastonite and BIO were associated with a trend for reduced As, Cd, and Pb in storage roots. These first-season study results suggest that WOL and BIO are potentially useful for follow-up studies to reduce the bioavailability and subsequent uptake of As, Cd, and Pb accumulation in sweetpotato under organic production systems.
