[DA-6 and GLDA Enhanced Pancium virgatum L. to Phytoextract Cd from Contaminated Soils]

To reveal the effects of diethyl aminoethyl hexanoate (DA-6) combined with L-Glutamic acid, N,N-diacetic acid (GLDA) on the remediation of Cd contaminated soils by Panicum virgatum L., different GLDA application methods with total application doses of 600, 1200, and 2400 kg·hm^-2equally divided 1, 2, and 4 times, respectively, were studied on the basis of DA-6 concentrations of 0 and 10 μmol·L^-1, and application intervals (2 and 4 times) were 30 and 15 days, respectively, over 60 days. Soil pH, dissolved organic carbon (DOC), biomass and Cd contents, Cd extraction, total Cd, and available Cd (DTPA-Cd) were analyzed. The results showed that first, the combination of DA-6 and GLDA could improve soil pH and DOC, and the pH and DOC increased significantly with increased GLDA application. Secondly, the combination of DA-6 and GLDA could significantly improve the biomass and Cd contents of Panicum virgatum L., and for DA-6, the amounts and times of GLDA application were the most important factors affecting the biomass and Cd contents. Third, the highest amount of Cd extracted was 22.18g·hm^-2 at 1200 kg·hm^-2 GLDA applied 4 times and 10μmol·L^-1 DA-6, which was 1.93 times higher than CK (wherein no DA-6 and GLDA were applied) and 1.23 times higher than 10D0 (in which only DA-6 was applied). Finally, the lowest soil total Cd was 0.529mg·kg^-1 at 2400 kg·hm^-2 GLDA applied 2 times and 10 μmol·L^-1 DA-6, which was 21.04% lower than CK and 18.23% lower than 10D0. Therefore, the combination of DA-6 and GLDA can further strengthen the recovery of Cd contaminated farmlands via Panicum virgatum L..