Effects Of Fulvic Acid Organic Fertilizer On Heavy Metals In Soil Contaminated By Hg,Pb And Hg

With the rapid development of modern economy and the increasing impact of various unreasonable industrial and agricultural activities on the soil ecological environment is increasingly strengthened,and the problem of soil heavy metal pollution is increasingly serious.Existing research result have been confirmed that the application of fulvic acid organic fertilizer can not only effectively maintain and improve soil fertility,promote crop growth and development,but also reduce the effectiveness of heavy metals,reduce soil heavy metal pollution,and improve soil ecological environment.This study was the soil culture pot experiment in simulated nature,and it was used wheat as the experimental crop and fulvic acid organic fertilizer as the experimental fertilizer.Test included two kinds of pollution modes such as a single pollution of mercury,and lead/mercury combined pollution with applying fulvic acid organic fertilizer.To study the effects of different application amount of fulvic acid organic fertilizer on germination rate,soil pH,nitrogen content,phosphorus content,organic matter content,Pb and Hg content in soil and wheat plant and bioavailability.And the ecological effects of different application amounts of fulvic acid organic fertilizers on soil fertility and accumulation amounts of heavy metals Pb and Hg were studied to provide theoretical and data references for the study and application of fulvic acid organic fertilizers and the treatment and remediation of soil heavy metal pollution.The following is studied:?1?The effect of fulvic acid organic fertilizer on plant development;?2?The effect of fulvic acid organic fertilizer on soil fertility;?3?The effect of fulvic acid organic fertilizers on the migration and fixation of heavy metals in soil and wheat.The specific research results are as follows:?1?The application of fulvic acid organic fertilizer could effectively promote the germination of wheat seeds in either Hg single contaminated soil or Pb and Hg combined contaminated soil.Compared with the CK group without fertilizer,the initial germination rate of wheat was significantly increased,and when the application amount of fulvic acid organic fertilizer reached to 6 g?kg^-1,it was reached the maximum value,which was 90.67%?Soil contaminated with Hg?,89.33%?Soil contaminated with Hg?,increased by 15.34%and 19.27%respectively.However,when the application amount of fulvic acid organic fertilizer reached 10 g?kg^-1,the germination rate of wheat seeds decreased?lower than that of CK group?,this indicated that fulvic acid organic fertilizer with a concentration of more than 10 g?kg^-11 could inhibit the germination of wheat seeds.?2?The application of fulvic acid organic fertilizer significantly improved the properties of soil,whether in Hg single contaminated soil or Pb and Hg combined contaminated soil.Among them,the nitrogen and phosphorus content in the soil and the soil organic matter content increased with the application amount of fulvic acid organic fertilizer,and the maximum value was obtained when the application of fulvic acid organic fertilizer was 10g?kg^-1.At the same time,the application of fulvic acid organic fertilizer also increased the pH value of the soil.?3?The application of fulvic acid organic fertilizer significantly reduced the bioavailability of heavy metals Pb and Hg in the soil,whether in Hg single contaminated soil or Pb and Hg combined contaminated soil.And the content of Hg in wheat plants decreased,the content of Pb decreased slightly.With the extension of application time of fulvic acid organic fertilizer,the content of Pb and Hg in soil significantly decreased.This indicated that the application of fulvic acid organic fertilizer could reduce bioavailability of heavy metals Pb and Hg,fix and passivate heavy metals Pb and Hg,and reduce their mobility,thus reducing the uptake of heavy metals Hg by wheat plants.This study showed that fulvic acid organic fertilizer has significant improvement on soils properties,which could promote the germination of wheat seeds,promote the growth and development of wheat plants,increase soil fertility,reduce bioavailability of heavy metals Pb and Hg,and reduce their mobility.In a comprehensive consideration,the wheat growth and soil property inprovement were most signifiant when the application of fulvic acid organic fertilizer was 6 g?kg^-1.