129
The application of a compound mineral fertiliser to sod-podzolic sandy loam soil
provided a reduction in the content of
238
U by 1.4–1.5 times in barley grain and by
1.3 times in straw. This was due to the recharge of phosphorus and potassium in the
soil and a balanced application of nitrogen. The TF of
238
U (Bq kg
−1
of grain)
(kBq m
−2
)
−1
on sod-podzolic medium loamy soils with the application of mineral
fertilisers was (5.1−7.5) × 10
−3
, which is 1.2 times lower than on control. Under the
same conditions of cultivation of barley on sod-podzolic medium loamy soils, it is
possible to obtain grain and coarse fodder with a lower content of
238
U in comparison with sod-podzolic soils. The high efficiency of mineral fertilisers was noted to
reduce the transfer of
238
U to barley on grey forest soil and leached chernozem. The
smallest quantity of
238
U in barley grain and straw accumulates when applying mineral fertilisers to leached chernozem. The effectiveness of mineral fertilisers in
reducing the accumulation of
238
U in barley yield grown on leached chernozem was
1.3–1.4 times higher than on grey forest soil.
4.2 Influence of Mineral Fertilisers and Ameliorants
on the Accumulation of
238
U in the Cereal Crops
The experimental evaluation of the influence of lime, mineral and organic fertilisers
on the entrance of
238
U into oats and barley was carried out under conditions of
microplot field experiments on sod-podzolic sandy loam soil. The following are the
agrochemical characteristics of the soil before the establishment of the experiments:
the humus content was 0.98%; pH KCl was 4.1; hydrolytic acidity was 4.5 mg-eq
(100 g of soil)
−1
; Ca content was 1.7 mg-eq (100 g of soil)
−1
; and the content of
mobile phosphorus and exchangeable potassium was 78 and 51 mg kg
−1
,
respectively.
Ameliorants (lime and humus) were applied in accordance with the experience
scheme in the autumn, and mineral fertilisers in the form of NPK were applied in
spring.
238
U was introduced into the soil in the form of uranyl chloride, in concentration 50 mg kg
−1
of soil or 625 Bq kg
−1
. The plot area was 1 m
2
, and the number of
replications in the experiment was 4. Flexible PVC, which was dug into the ground,
contoured each plot in order to eliminate the horizontal migration of
238
U. The protective zone between the plots was 2 m.
The negative effect of
238
U with the contamination density of sod-podzolic sandy
loam soil 187.5 kBq m
−2
on the growth and development of oats and barley did not
appear. In the control variant, the growth inhibition of plants, mainly barley, was
noted due to the reduced supply of plants with nitrogen, phosphorus and potassium,
which led to the low grain yield of the crops.
Application of mineral fertilisers to the sod-podzolic sandy loam soil in a dose of
N 80 P 80 K 80 facilitated the reduction of the content of
238
U by 1.2 times in the oats
grain and by 1.5 times in the oats straw in comparison with the control (Table 9).
The Behaviour of Uranium in Soils and the Mechanisms of Its Accumulation…
The application of a compound mineral fertiliser to sod-podzolic sandy loam soil
provided a reduction in the content of
238
U by 1.4–1.5 times in barley grain and by
1.3 times in straw. This was due to the recharge of phosphorus and potassium in the
soil and a balanced application of nitrogen. The TF of
238
U (Bq kg
−1
of grain)
(kBq m
−2
)
−1
on sod-podzolic medium loamy soils with the application of mineral
fertilisers was (5.1−7.5) × 10
−3
, which is 1.2 times lower than on control. Under the
same conditions of cultivation of barley on sod-podzolic medium loamy soils, it is
possible to obtain grain and coarse fodder with a lower content of
238
U in comparison with sod-podzolic soils. The high efficiency of mineral fertilisers was noted to
reduce the transfer of
238
U to barley on grey forest soil and leached chernozem. The
smallest quantity of
238
U in barley grain and straw accumulates when applying mineral fertilisers to leached chernozem. The effectiveness of mineral fertilisers in
reducing the accumulation of
238
U in barley yield grown on leached chernozem was
1.3–1.4 times higher than on grey forest soil.
4.2 Influence of Mineral Fertilisers and Ameliorants
on the Accumulation of
238
U in the Cereal Crops
The experimental evaluation of the influence of lime, mineral and organic fertilisers
on the entrance of
238
U into oats and barley was carried out under conditions of
microplot field experiments on sod-podzolic sandy loam soil. The following are the
agrochemical characteristics of the soil before the establishment of the experiments:
the humus content was 0.98%; pH KCl was 4.1; hydrolytic acidity was 4.5 mg-eq
(100 g of soil)
−1
; Ca content was 1.7 mg-eq (100 g of soil)
−1
; and the content of
mobile phosphorus and exchangeable potassium was 78 and 51 mg kg
−1
,
respectively.
Ameliorants (lime and humus) were applied in accordance with the experience
scheme in the autumn, and mineral fertilisers in the form of NPK were applied in
spring.
238
U was introduced into the soil in the form of uranyl chloride, in concentration 50 mg kg
−1
of soil or 625 Bq kg
−1
. The plot area was 1 m
2
, and the number of
replications in the experiment was 4. Flexible PVC, which was dug into the ground,
contoured each plot in order to eliminate the horizontal migration of
238
U. The protective zone between the plots was 2 m.
The negative effect of
238
U with the contamination density of sod-podzolic sandy
loam soil 187.5 kBq m
−2
on the growth and development of oats and barley did not
appear. In the control variant, the growth inhibition of plants, mainly barley, was
noted due to the reduced supply of plants with nitrogen, phosphorus and potassium,
which led to the low grain yield of the crops.
Application of mineral fertilisers to the sod-podzolic sandy loam soil in a dose of
N 80 P 80 K 80 facilitated the reduction of the content of
238
U by 1.2 times in the oats
grain and by 1.5 times in the oats straw in comparison with the control (Table 9).
The Behaviour of Uranium in Soils and the Mechanisms of Its Accumulation…