1. Does sulfur fertilizer influence Cu migration and transformation in colloids of soil pore water from the rice (Oryza sativa L.) rhizosphere?
- Author
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Sun, Lijuan, Xue, Yong, Peng, Cheng, Xu, Chen, and Shi, Jiyan
- Subjects
SULFUR fertilizers ,RICE ,PORE water ,COLLOIDS ,POLYCHLORINATED naphthalenes - Abstract
Abstract Colloids are ubiquitous in soils, and it has been reported that colloids can act as carriers to increase the mobility of poorly soluble contaminants in subsurface environments. Addition of sulfur (S) fertilizer greatly influences on heavy metal behavior in paddy soil, while the influence of S fertilizer on Cu migration and transformation in colloids of soil pore water has not yet been studied. The influence of S fertilizer (S
0 and Na 2 SO 4) applied in paddy soils on Cu migration and transformation in colloids of soil pore water from the rice rhizosphere region was explored in this study. The speciation of Cu in colloids of soil pore water from the rice rhizosphere region was explored by advanced synchrotron-based X-ray absorption near-edge spectroscopy (XANES) techniques. The morphology of colloids was characterized by field emission scanning electron microscopy coupled to energy dispersive X-ray spectroscopy (SEM-EDX). At a depth of 20 cm, the concentration of Cu in colloids of the rhizosphere soil pore water in the control was 2.4- and 6.5- fold higher than that in treatments of S0 and Na 2 SO 4 , respectively. The colloids in soil pore water were all positively charged, ranging from 2.4 to 7.8 mV, and the size of colloids was 440–740 nm. The proportion of Fe in colloids in the rhizosphere region decreased with S fertilizer application, while the proportions of C and O increased. Sulfur fertilizer application, increased the proportion of Cu-Cysteine, while the proportion of Cu 2 S decreased in soil colloids. In conclusion, application of sulfur fertilizer in paddy soil decreased the Cu concentration in soil pore water and colloids of the rhizosphere region, thereby decreasing the vertical migration of Cu in soil pore water. Graphical abstract The effect of sulfur fertilizer on Cu migration and transformation in colloids of soil pore water from the rice rhizosphere region. Image 1 Highlights • Sulfur fertilization decreased the concentration of Cu in pore water colloids from the rice rhizosphere region. • The proportion of Fe in pore water colloids in the rhizosphere region decreased with S fertilizer application while C and O increased. • Sulfur fertilization increased the proportion of Cu-Cysteine in pore water colloids from the rice rhizosphere region, while Cu 2 S decreased. [ABSTRACT FROM AUTHOR]- Published
- 2018
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