Can liming reduce barium uptake by agricultural plants grown on sandy soil?

Abstract

Uptake of barium (Ba) from soil by vascular plants varies among species. Despite the toxicity of soluble Ba compounds to plants, research on mechanisms controlling Ba uptake from natural soils is scarce. This study investigated the treatment effect of lime (CaCO3) added to a sandy soil containing a total of 500 mg Ba kg−1 on uptake and interspecies distribution of Ba in legumes and other cultivated food and feed plants. Nine species of grasses, vegetables, herbs, and legumes were cultivated under controlled conditions in a greenhouse experiment. The plants were harvested at maturity or flowering, dried, milled, and digested with nitric acid using the microwave technique prior to ICP‐MS analysis. All plant species acquired Ba from the soil in considerable amounts, probably due to low Ba adsorption potential of the sandy soil. Shoot tissue concentrations ranged from about 100 (grass) to 600 mg Ba kg−1 (legume) and root concentrations from about 100 (tuber vegetable) to 700 mg kg−1 (legume). Vicia cracca L. (bird vetch) showed an accumulation capacity due to high shoot concentrations of Ba compared to the other species. Higher yield accompanied by a potential dilution effect can partly explain why Trifolium repens L. (white clover), Pisum sativum ssp. arvénse L. (gray pea) and Hordeum vulgare L. (barley) did not display the highest Ba concentrations, but showed the highest Ba uptake from soil. High plant uptake of calcium (Ca) also seemed to enhance Ba uptake, by legumes in particular. However, liming reduced shoot Ba concentrations, particularly of species with low affinity for Ca. The risk of Ba accumulation thus raises toxicity concerns when forage legumes are cultivated in soils containing elevated concentrations of Ba.

Bioavailability of barium to Trifolium pratense L. in soils contaminated with drill cuttings

“…The content of Ba in plant tissues depends on numerous factors, including the plant species and the concentration of Ba in the soil, as well as the physicochemical properties of Ba and the condition of the soil, e.g., its humidity or aeration. The dependency of Ba accumulation on plant species is confirmed by the results obtained by Myrvang et al (2016). They demonstrated that legumes exhibit a higher accumulation of Ba from soil than grasses, vegetables or herbs.…”

“…The study also found significant Ba removal capabilities in silvergrass Miscanthus floridulus. Barium accumulation was also observed in the biomass of southern cattail (Typha domingensis), papyrus sedge (Cyperus papyrus) (Ribeiro et al, 2018), Indigofera cordifolia (Raghu, 2001), Brazil nuts (Bertholletia excels), different mushrooms (Harbison et al, 2015) and some legumes (Myrvang et al, 2016). The latter observed that bird velch (Vicia cracca L.) and white clover (Trifolium repens L.) examined in a pot experiment carried out on sandy soil accumulated a higher amount of Ba than barley, tall fescue, carrot, radish and spinach.…”

The use of carbonatite rock powder as a liming agent

“…). Myrvang et al () also demonstrated Ba uptake from this particular sand to tall fescue and white clover in a previous work. Despite that the sand contained nearly 20 times more Ba than carbonatite, an additional contribution to plant Ba from carbonatite was still evident, as shown in Fig.…”

“…) and the close relationship between these two elements (Fig. ) agrees well with findings reported by Myrvang et al (). They reported that white clover accumulated these elements more effectively than tall fescue.…”

“…Still, the plant concentrations of Ba observed were well below concentrations reported to cause internal toxicity symptoms, such as the Ba blocking of K channels in soybeans ( Llugany et al, ) and Tanzanian guinea grass ( Monteiro et al, ). Compared to uptakes reported by Myrvang et al (), the relatively low uptake of Ba by tall fescue and white clover was possibly related to Ba precipitation with sulfate ( Kabata‐Pendias , ) applied in the nutrient solutions. In light of that, plants sampled at Stjernøy ( Myrvang et al, ) grew directly on rocks weathered since the last Ice Age (8000–9000 years ago), whereas plants grown in pots were exposed to the same rock only recently crushed and ground.…”