Study On REE Geochemistry In Soil And The Effect On Quality Of Apple-pear

Apple-pear, as" product of quality on a ministry scale " and "green product", is the particularly mainstay industry product in Yanbian Korean Autonomous Prefecture. And to research in the characteristics of the rare earth elements in the soil environment for the tree growing and to explore the relationship between the fruit and the chemical traits of the rare earth elements must be beneficial to the quality of the apple-pear, and it is of great reallife and economic significance for proper apple-pear growing in Yanbian.This paper chose Sanhe, Longjing, Hunchun and Tumen as the typical areas due to their different geological background in Yanbian. The topsoil, profile soil and samples of the apple-pear were collected one the basis of the regional natural economic background, geological and hydrological conditions, as well as soil information, with the relevant theories of agrology, geochemistry, and the soil resource science. In addition to the total content of the rare earth elements and the efficacious elements in soil, the apple-pear samples'elemental components and quality were tested. Based upon the recursion theory of the geochemistry and the principles of the statistics, the geochemical characteristics in the rare soil elements were analyzed, and the effects of the soil environment upon the rare soil elements were discussed, which integrated with the relationship between the distribution features of quality and the elements contents in the sample, the fruit quality effected by the rare soil elements was further studied. The final conclusions can be drawn as follows:1. REE levels in all the soil samples except those collected from Sanhe area were under the average level of China Mainland, the content curves of REE followed the Oddo-Harkin rule strictly, LREE and HREE separated obviously, showing enrichment of light REE and negative Eu anomaly.2. There were some differences of the REE content between slope top and bottom, but the soil usage pattern produced little effect on the REE distribution. In the soil profile, REE's contents increased from top to bottom in Longjing, Tumen study area;but in Sanhe, Hunchun ,the result is opposite. Directional distribution is also affected by the Weathered crust,parent soil material and hydrologic condition.3. The distribution curve of effective state's content of rare-earth element in the study area close to log-normal distribution, and due to different soil types, pH value, or landforms conditions, the transformation of the coefficient is different from the total to effective state; the entire amount of rare earth elements in soil and effective state of the content was highly significant positive correlation.4. Soil environment influence the distribution of rare earth elements. Al, Si, Cu, Mn, Fe and Zn elements in the surface soil and rare earth elements in soil was significantly associated .Al, Cu, Mn, Fe, Zn was positively except Si show a negative correlation; rare earth elements and PH value in soil were associated significantly positive, while associated with soil texture but without organic matters.5. In research region, the content of REE is dissimilar in soils from different regions; by and large,the correlations between REE in soils and quality in fruits are currently,and after t-test the correlations are significant under 0.05 and 0.01 confidence level; and the apple pear's total sugar,Vitamin C, the soluble solid shape are positive correlations with the soil rare-earth element; total acid,water content and degree of hardness content are negative correlations with it.6. Rare earth elements in soil and Ca, Cu and B's content of apple-pear are negatively correlated. In a certain extent, rare earth elements affected the accumulation of nutrients. Its content and accumulated coefficient of Ca, Mg, K,C u, Zn, Mo and Mn was negatively correlated, in which light rare earth and accumulated coefficient of Ca, Mg K, Cu was a very significant negatively correlated.