Rare Earth Elements On The Form Of Distribution Of Soil Nitrogen And Phosphorus Transformation And Bioavailability

Amrnoniuin-N and nitrate plus nitrite-N as well as pH in the soil amended with urea plus different levels of rare earth elements (REEs), were determined in the soil cultivation experiment without plant. Above the level of 10mg REEs kg?dry soil, the hydrolysis of applied urea was delayed to some extent and the nitrification of its produced aninionium-N was diminished. This was beneficial to the reduction of gaseous N loss and leaching N out of surface layer soil and to the retention of applied urea-derived N in soil. The influence of REEs on the properties of phosphorus adsorption in soil was investigated by Langmuir equilibrium absorption curve. It was found that REEs application could reduce the amount of absorbed phosphorus by soil and was conducive to the supplement of soil phosphorus. The influences of REEs on the distributions of soil nitrogen and phosphorus forms and their available contents, were investigated by rhizobox experiment with seedling maize. The contents of available nitrogen and phosphorus in rbizosphere and non- rhizosphere soil amended R.EEs were reduced, and the extent of enrichment of available nitrogen and phosphorus in rhizosphere soil would reduce with the increase of the amount of applied REEs. At high amount of applied REEs, the mineralization of organic nitrogen and urease activity in rbizosphcre and non-rhizosphere REEs- treated soil were significantly inhibited. Therefore, these above phenomena would induce the uptake of nitrogen and phosphorus by seedling maize.