Authors: Binggan Wei Jiangping Yu Yunshe Dong Linsheng Yang Jing Wang Yuan Xue Shufang Guo
Publish Date: 2015/10/22
Volume: 23, Issue: 4, Pages: 3632-3640
Abstract
Drip irrigation systems have been widely applied in semiarid and arid regions of China However little is known about the migration of heavy metals in cultivated soil under drip irrigation Therefore the concentrations of Cd Cr Cu Ni Pb and Zn in soil were determined The mean contents of Cd Cr Cu Pb Zn and Ni in surface soil subjected to irrigation with low and high amounts of water W1 and W2 were 011 11750 3751 1353 7810 and 3841 mg/kg and 020 9445 2971 2248 6300 and 3662 mg/kg respectively Metal concentrations in deep soil varied slightly between W1 and W2 Among different distances from the dropper the metal levels in surface soil varied widely while they varied slightly in deep soil The I geo geoaccumulation index values indicated that the soil was usually contaminated by Cr Cu and Cd Under W1 Cd and Cu usually accumulated in surface soil near the dropper while the other metals leached into subsurface soil Moreover the metals generally accumulated in soil away from the dropper However significant leaching of metals to the subsurface and deep soil was observed near the dropper under W2 Away from the dropper Cd Cr Cu Ni and Pb usually accumulated in surface and deep soil This suggested that heavy metals generally migrated to the soil away from the dropper when subjected to lower amounts of irrigation while metals usually moved to surface soil and deep soil under high irrigation amounts These findings indicate that drip irrigation greatly affected the distribution and migration of heavy metals in soil with irrigation with lower amounts of irrigation water significantly affecting the horizontal migration of heavy metals and higher amounts influencing the vertical movement of heavy metals
Keywords: