Copper release kinetics: Effect of two extractants and wheat (Triticum aestivum L.) rhizosphere
2012
Motaghian, H.R., Shahrekord Univ. (Iran Islamic Republic). Dept. of Soil Science | Hosseinpur, A.R., Shahrekord Univ. (Iran Islamic Republic). Dept. of Soil Science
A greenhouse experiment was performed to determine Cu release characteristics in the bulk (B) and the rhizosphere (R) of some calcareous soils using rhizobox. The kinetics of Cu release were determined by successive extraction with diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA) and 10 mmol/L citric acid in a period of 1 to 504 h at 25+/-1 deg C. The results of kinetics studies showed that Cu extracted using DTPA-TEA was significantly lower in R than in B, while Cu extracted using citric acid was significantly higher in R than in B. The means of released Cu after 504 h using DTPA-TEA were 8.59 and 7.46 mg/kg in B and R, respectively. The mean release of Cu after 504 h using citric acid was 14.73 and 16.05 mg/kg in B and R, respectively. Release kinetics of Cu in two extractants conformed fairly well to parabolic diffusion, power function, and first order equations. The results of correlation analysis illustrated that a significant correlation between Cu desorption after 504 h with citric acid and Cu concentration in wheat was found (r = 0.96 and r = 0.90 in R and B, respectively, P less than 0.01). Therefore, the application of 10 mmol/L citric acid extractant would be recommended in the future study on the kinetics of release of Cu in calcareous soils.
显示更多 [+] 显示较少 [-]