[Influence of rare earth elements on chemical transformation of nitrogen in agricultural soil].
Soil available N, NH4(+)-N and NO3(-)-N contents and soil urease activity were measured after application of rave earth elements(REEs). The results showed that the contents of soil available N and NH4(+)-N were affected by application of REEs, being significantly differed from those in the control when the dosage was higher than 5 mg.kg-1 dry soil. However, soil NO3(-)-N content in treated plots did not differed from that in the control. No observed effect concentration (NOEC) for the potential influence of REEs on the chemical transformation and availability of soil available nitrogen was found to be 5 mg.kg-1 dry soil. The decrease of soil available N concentration was found closely correlated to the inhibition of soil urease activity (R2 = 0.87). It was suggested that the inhibition effect of REEs on the enzymatic nitrogen mineralization should be one of the major causes for the decline of soil available nitrogen concentration. The decrease of available nitrogen concentration occurred shortly after REEs application, indicating that there should be a self-regulation process to maintain the available nitrogen concentration in soil.
Liu
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SKLEAC, Research Center for Eco-Environmental Sciences, Beijing 100085.
Wang
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Z
D000383:Agriculture; D000641:Ammonia / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D014131:Trace Elements / Q000737:chemistry* / Q000633:toxicity; D014510:Urease / Q000187:drug effects / Q000378:metabolism
D009566:Nitrates; D012987:Soil; D014131:Trace Elements; D000641:Ammonia; D014510:Urease; D009584:Nitrogen