Typical sources of Cd to paddy fields in different contaminated areas and their impacts on Cd accumulation in topsoil and rice in Changzhutan, China

• Published in: Environmental research 2021-02, Vol.193, p.110523, Article 110523
• Main Authors: Wang, Fan, Peng, Liang, Zhou, Xihong, Zeng, Qingru, Luo, Si
• Format: Article
• Language: English
• Subjects: Atmospheric deposition; Cadmium; Cadmium - analysis; China; Humans; Oryza; Plant Breeding; Predictive analytics; Rice; Soil; Soil Pollutants - analysis; Sources
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2020.110523

Heavy metal pollution of soils has been worsening increasingly in China, which brings significant health risk to human, it is critical to investigate the sources of heavy metals in agricultural soils and explore the effects of heavy metal accumulation in crops. In this paper, the sources of cadmium (Cd) and their effects on Cd accumulation in soil and rice grown on urban farmland in Changzhutan were investigated. Among the main Cd sources (irrigation water, commercial fertilizer, and atmospheric deposition), the input flux of atmospheric deposition accounted for 76.36%–98.25% of total input flux, significantly higher than the input fluxes of irrigation water and commercial fertilizer. Manure fertilizer was also an important source of Cd in livestock breeding areas. The accumulation behaviors of Cd in soils and plants presented significant spatial variation among the study areas. Higher Cd input flux from atmospheric deposition resulted in higher Cd bioavailability in soil and more Cd accumulation in rice, and the newly deposited Cd contributed 7.35–41.23% in rice tissues. The use of manure fertilizer increased the soil pH and amount of available Cd in soil, as well as the accumulation of Cd in rice roots. Based on sequential extraction, acid-extractable Cd accounted for approximately 52.54%–61.88% of total Cd in atmospherically deposited particles in the study area, resulting in a high proportion of acid-extractable Cd in soil. This study provides useful reference data on the sources of Cd and its bioavailability in soil and rice. •Atmospheric deposition was the dominant source of Cd in all study areas.•Manure fertilizer in livestock breeding area also contributed greatly.•ZZ and LY topsoils exhibited more available Cd than the topsoils from AS and BS.•Cd from atmospheric deposition caused higher Cd mobility and bioavailability in soil.•Use of manure fertilizer increased the soil pH and accumulation of Cd in rice roots.