Speciation of rare earth elements in soil and accumulation by wheat with rare earth fertilizer application.
Speciation of rare earth elements in soil and accumulation by wheat with rare earth fertilizer application.
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DOI：
10.1016/s0269-7491(00)00143-3
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发表时间：
2001-05
影响因子：
8.9
通讯作者：
S. Zhang;X. Shan
中科院分区：
文献类型：
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作者：
S. Zhang;X. Shan
采用温室试验研究了稀土元素La、Ce、Pr和Nd在冬小麦（Triticum aestivum L.）以及施用稀土基肥料后这些元素在土壤中的形态。通过试验证实了作物产量的提高。La、Ce、Pr和Nd在小麦体内的累积行为随稀土施肥浓度的不同而不同，在低施肥量下随稀土浓度的增加而增加，在中等稀土浓度范围内基本不变，在高施肥量下随稀土浓度的增加而减少。根系稀土元素含量与土壤pH呈显著负相关（La含量r=-0.5787 ~-0.8442）。采用三级连续提取法，将施肥和未施肥土壤中的稀土元素分离为3个不同的组分：水溶态、交换态和碳酸盐结合态（B1），铁锰氧化物结合态（B2）和有机态和硫化物结合态（B3）。稀土元素主要存在于B2和B3两种形态中，B1形态中含量较少。B1和B2形态的稀土含量与土壤pH呈负相关（r=-0.6892 ~-0.8927和-0.7462 ~-0.9482）。B1组分中稀土元素含量与根系中稀土元素含量呈显著正相关。当施肥量低于20.0 mg/kg土时，相关系数在0.6159 ~ 0.7410之间。地上部稀土元素含量与土壤中各提取组分含量之间没有明显的相关性。
A greenhouse study was conducted to investigate the accumulation of rare earth elements (REEs), La, Ce, Pr and Nd, in winter wheat (Triticum aestivum L.), and the speciation of these elements in soil following the application of REE-based fertilizers. Improved crop yield was confirmed by the experiment. The accumulation behavior of La, Ce, Pr and Nd in wheat varied depending on the concentration of REE fertilizer application, i.e. increased with increasing REE concentration at low fertilization application, constant over the medium REE range, and decreased with increasing REE concentration at high fertilizer application. Significant negative correlation was obtained between REE contents in roots and soil pH (r=−0.5787 to −0.8442 for La). REEs in both the fertilized and unfertilized soils were fractionated by a three-stage sequential extraction procedure into three chemically distinct fractions: water soluble, exchangeable and carbonate bound (B1), Fe–Mn oxide bound (B2), and organic and sulfide bound (B3). REEs in fertilized soils were found mainly in the B2 and B3 fractions, with only a small amount in the B1 fraction. REEs in B1 and B2 fractions were negatively correlated with soil pH (r=−0.6892 to −0.8927 and −0.7462 to −0.9482). Significant correlation was obtained between REEs in B1 fraction and REE contents in root. The correlation coefficients ranged from 0.6159 to 0.7410 when fertilizer application was lower than 20.0 mg/kg soil. No acceptable relationship was observed between REE contents in shoot and any of the extractable fractions in soils.