Response of rice and soil to the application of rare earth elements

摘要

Low dose of lanthanum (La) (0.05-1.5 mg·L<'-1>) significantly increased rice production in nutrient solution culture experiment, but no significant effect was found in soil culture, either by glasshouse pot or field experiments. The enhancement is probably attributed to the plant hormones adjustment. La application increased the La content in rice root and straw, but did not change the concentration in seeds. Calcium was decreased in the rice straw and seed. Phosphorus was increased in the rice root and mainly existed as inorganic and chelate compounds. Application of La led to the increases of exchangeable La and Al in soil, which were more significant in the red soil than in the paddy soil. The long-term application of lanthanum would lead to the leaching of soil Ca, Mg, K and Na. It should not be encouraged for the application in agriculture.