High Plant Uptake of Radiocesium from Organic Soils Due to Cs Mobility and Low Soil K Content

Abstract

Post-Chernobyl experience has demonstrated that persistently high plant transfer of 137 Cs occurs from organic soils in upland and seminatural ecosystems. The soil properties influencing this transfer have been known for some time but have not been quantified. A pot experiment was conducted using 23 soils collected from selected areas of Great Britain, which were spiked with 134 Cs, and Agrostis capillaris grown for 19-45 days. The plant-tosoil 134 Cs concentration ratio (CR) varied from 0.06 to 44; log CR positively correlated to soil organic matter content (R 2 ) 0.84), and CR values were highest for soils with low distribution coefficients (K d ) of 134 Cs. Soils with high organic matter contents and high concentrations of NH 4 + in solution showed high 134 Cs mobility (low K d ). The plantto-soil solution 134 Cs ratio decreased sharply with increasing soil solution K + . A two parameter linear model, used to predict log CR from soil solution K + and K d , explained 94% of the variability in CR values. In conclusion, the high transfer of 134 Cs in organic soils is related to both the high 134 Cs mobility (low clay content and high NH 4 + concentrations) and low K availability.

Potassium fertilizer and other materials as countermeasures to reduce radiocesium levels in rice: Results of urgent experiments in 2011 responding to the Fukushima Daiichi Nuclear Power Plant accident

“…Fesenko et al (2007) positively reported lime application. Plant uptake of Cs is rather high in organic soils (Sanchez et al 1999) mainly because of low soil adsorption and higher ammonium nitrogen nutrition. In contrast, Cs uptake of rice plant was decreased by manure application (Tsumura et al 1984).…”

A preliminary assessment on the use of biochar as a soil additive for reducing soil-to-plant uptake of cesium isotopes in radioactively contaminated environments

“…Calcareous soils also contain little or no Al-Si based clay material. The deficiency in K and absence of clay minerals yield conditions that enhance the uptake of 137 Cs into plants similar to that found in peat and other rich organic soils (9)(10) and on soil-to-plant uptake of 137 Cs (to be published elsewhere). The tracer distribution experiments were carried out in 250 mL Erlenmeyer flasks sitting on a rotating table.…”

Effect of Nitrogen Fertilization on Radiocesium Absorption in Soybean

“…Moreover, we considered that potassium absorption might compete with ammonium absorption because both ions are univalent cations; hence, the soybeans may lack potassium. A lack of potassium has been found to increase cesium absorption [9,12,13]. However, the potassium concentrations in soybean did not decrease with ammonium fertilization.…”

“…We found that the amount of radiocesium extracted by ammonium fertilizer increased the day after fertilization; therefore, soybean could absorb radiocesium. In addition, the ammonium and cesium ions are both univalent cations, and ammonium has been found to restrict cesium absorption in the hydroponics [9][10][11]. This study was used by soil.…”

“…To revitalize agriculture, Fukushima Prefecture has been promoting the decontamination of agricultural lands; consequently, it has implemented an increase in the exchangeable potassium content in soil used to grow rice to approximately 25 mg 100 g 1 (dry soil) or higher. This occurred because it recently became clear that potassium fertilization was effective for reducing the radiocesium concentration in agricultural crops [8,9]. Nitrogen (N) has a large effect on crop growth, and some reports have suggested that it also promotes the radiocesium absorption [10,11].…”