タグ「Grass」
Title: Transfer of radiocesium from uncultivated soils to grass after the Chernobyl accident
Author: Z. Pietrzak-Flis, P. Krajewski, G. Krajewska, N.R. Sunderland
Reference: Science of The Total Environment, Volume 141, Issues 1–3, 25 January 1994, Pages 147-153
DOI: http://dx.doi.org/10.1016/0048-9697(94)90024-8
Keywords: Radiocesium; Grass; Soil; Transfer factor; Chernobyl
Abstract: Transfer of radiocesium from uncultivated peat, loam and two sandy soils to grass in northeastern Poland was evaluated. Samples of grass and soil were collected from the same area of about 100 m2 in the period from June 1988 to November 1991 twice a year. Grass was sampled from 1 m × 1 m squares by cutting to the plant base. Afterwards core samples of soil were taken from an area of 132.73 cm2. 134Cs, 137Cs and 40K were determined by gamma spectrometry. The average concentration of 137Cs (to 10 cm depth) in the studied areas was in the range from 22.8 ± 2.5 Bq kg−1 to 154.3 ± 13.7 Bq kg−1. The average concentration of this radionuclide in grass varied from 6.76 ± 0.99 Bq kg−1 dry weight (dry wt.) to 152.6 ± 37.4 Bq kg−1 dry wt and depended upon the type of soil. The transfer of radiocesium to grass in the studied soils decreased in the following order: Sand I > peat > Sand II > loam. The results indicated that apart from soil, other parameters also influenced the transfer of radiocesium to grass. It has been found that 134Cs from Chernobyl is more available to grass than 137Cs from nuclear weapon tests.
URL: http://www.sciencedirect.com/science/article/pii/0048969794900248
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden: III. County of Västernorrland
Author: K. Rosén, E. Haak, Å. Eriksson
Reference: Science of The Total Environment, Volume 209, Issues 2–3, 19 January 1998, Pages 91-105
DOI: http://dx.doi.org/10.1016/S0048-9697(98)80100-9
Keywords: Radiocaesium; Radioiodine; Chernobyl; Nuclear fallout; Grass; Cereals
Abstract: In 1986 a large number of farms in the Chernobyl-affected area in the county of Västernorrland in northern Sweden were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0–5 cm) in 1986 and the crop products in 1986–1996 were analysed. The aim was to study the impact of soil and crop rotation on sensitivity of 137Cs transfer in a short and long term perspective. In the fallout year 1986 the transfer to grass was usually much higher than to cereal grain. In this year the transfer to grass was usually much higher in the first cut rather than the second cut. The reduction in transfer with year was large but variable with site and with crop sequence. Ploughing was effective in decreasing the transfer of 137Cs to crops. On arable sites in 1986 the transfer to cereal straw was larger at late stem elongation (LSE) than at the maturing stage. Unexpectedly, there was no clear relationship between transfer of 137Cs to the crops and any of the soil characteristics. In 1986 the transfer of 131I to grass and cereals was also investigated on some of the farms. The results are compared with the transfer of 137Cs, 2 months after the Chernobyl fallout.
URL: http://www.sciencedirect.com/science/article/pii/S0048969798801009
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden. II. Marginal and seminatural areas in the county of Jämtland
Author: Klas Rosén
Reference: Science of The Total Environment, Volume 182, Issues 1–3, 5 April 1996, Pages 135-145
DOI: http://dx.doi.org/10.1016/0048-9697(95)05059-0
Keywords: Radiocaesium; Grass; Fallout; Chernobyl; Contamination
Abstract: In 1986, two Chernobyl-affected areas in the county of Jämtland, a mountain area and a river valley area, were investigated as to radiocaesium behaviour and transfer to grass. The soil surface layer (0–10 cm) in 1986 and 1989 and grass samples in 1986–1994 were analysed on 9 temporary grassland sites and 8 permanent pasture sites, described individually. The aim of this investigation was to study the sensitivity of different soil types and the influence of normal farming practices, ploughing and K-fertilization on the caesium transfer, in short- and long-term perspectives after the Chernobyl fallout. As expected, the transfer of 137Cs to grass was usually higher on permanent pasture than on temporary grassland. For both types of grassland, however, there was a considerable but different change of transfer with years. The transfer to grass in the year of the fallout, 1986, depended to a large extent on the thickness and interception capacity of the grass sward. In the following years, it also depended on the caesium-fixing capacity to clay minerals, on K-fertilization and the reverse process of K removal by plant uptake. Ploughing down the contaminated surface layer and the mixing of caesium with mineral soil were effective in reducing the transfer. During the period 1986–1994, the transfer was reduced considerably, showing a range of (0.1–177.3 m2/kg d.w.) × 10−3. The calculated annual reduction halftime, Tar, increased with years after fallout. It is clearly shown that both countermeasures, ploughing and K-fertilization, are of potential value to decrease grass contamination. Where both measures were employed a reduction in the range of 78%–95% was recorded in the year after ploughing.
URL: http://www.sciencedirect.com/science/article/pii/0048969795050590
Title: Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden. I. County of Gävleborg
Author: Klas Rosén, Åke Eriksson, Enok Haak
Reference: Science of The Total Environment, Volume 182, Issues 1–3, 5 April 1996, Pages 117-133
DOI: http://dx.doi.org/10.1016/0048-9697(95)05056-6
Keywords: Radiocaesium; Chernobyl; Nuclear fallout; Cereals; Grass
Abstract: In 1986, 15 farms in the Chernobyl-affected area of the county of Gävleborg were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0–5 cm) in 1986 and the crop products in 1986–1994 were analysed. The aim was to study the impact of site and soil characteristics on sensitivity of 137Cs transfer in a long-term perspective. The transfer was much higher to grass than to cereal grain. For both crop products, however, there was a considerable annual reduction. For grass, and especially in the fallout year 1986, the transfer depended on interception capacity of the stubble and grass sward, on soil fertility and K-fertilization as well as on dilution by crop growth. In the following years, the annual reduction in transfer to grass was reduced by a factor of 2 to 100. Both ploughing through the surface layer and the mixing of radiocaesium with soil contributed to a decreased transfer of radiocaesium to crops. Thick stubble and grass sward on the grassland sites was the main reason for a lag period of high persistent transfer. The annual reduction was less on organic than on mineral soils. Measures to decrease the transfer to crops are discussed in relation to a new concept to evaluate the long-term behaviour of 137Cs in agricultural environments
URL: http://www.sciencedirect.com/science/article/pii/0048969795050566
