Application of rare-earth elements in the agriculture of China and its environmental behavior in soil.
Rare-earth elements (REEs) have been used in fertilizers in the agriculture of China for about 20 years. They have been shown to be beneficial elements for plants. For example, they have improved the yield and quality for several kinds of crops. This paper reviews the current literature on studies of REEs being used as fertilizers. Some studies have focused on the effects of REEs on metabolic nutrients, photosynthesis and stress resistance of plants. Other studies have shown that the environmental behaviors of REEs in soil are dominated by their low solubility. Fluorides, carbonates, phosphates and hydroxides may form neutral complexes containing REEs with a low solubility. The amount of extraneous REEs demonstrate the following relationship: residual >> bound to organic matter > bound to Fe-Mn oxides > bound to carbonate >> exchangeable and water soluble forms. The adsorption capacity of REEs depends on the clay type and the content of amorphous and manganese oxides, whereas the desorption of REEs is usually very low. At the end of the paper, authors discuss the needs for future environmental research on REEs, which would shed new light on the effects of REEs on agriculture, environment and human health.
Pang
Xin
X
SKLEAC, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, P.R. China. xinpangp@hotmail.com
Li
Decheng
D
Peng
An
A
D002681:China; D018556:Crops, Agricultural; D005308:Fertilizers; D006801:Humans; D008674:Metals, Rare Earth / Q000032:analysis* / Q000494:pharmacology*; D063245:Plant Development; D010944:Plants / Q000187:drug effects*; D012989:Soil Pollutants
D005308:Fertilizers; D008674:Metals, Rare Earth; D012989:Soil Pollutants