A field study on the dynamic uptake and transfer of heavy metals in Chinese cabbage and radish in weak alkaline soils

Abstract

Vegetables and crops can take up heavy metals when grown on polluted lands. The concentrations and dynamic uptake of heavy metals vary at different growth points for different vegetables. In order to assess the safe consumption of vegetables in weak alkaline farmlands, Chinese cabbage and radish were planted on the farmlands of Baiyin (polluted site) and Liujiaxia (relatively unpolluted site). Firstly, the growth processes of two vegetables were recorded. The growth curves of the two vegetables observed a slow growth at the beginning, an exponential growth period, and a plateau towards the end. Maximum concentrations of copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) were presented at the slow growth period and showed a downtrend except the radish shoot. The concentrations of heavy metals (Cu, Zn, and Cd) in vegetables of Baiyin were higher than those of Liujiaxia. In the meanwhile, the uptake contents continued to increase during the growth or halted at maximum at a certain stage. The maximum uptake rates were found on the maturity except for the shoot of radish which took place at the exponential growth stages of root. The sigmoid model could simulate the dynamic processes of growth and heavy metals uptake of Chinese cabbage and radish. Conclusively, heavy metals have higher bioaccumulation tendency for roots in Chinese cabbage and for shoots in radish.

Contrasting Effects of Cattle Manure Applications and Root-Induced Changes on Heavy Metal Dynamics in the Rhizosphere of Soybean in an Acidic Haplic Fluvisol: A Chronological Pot Experiment

“…These results illustrate that within the application rate range of CM1, CM2, and CM3 (10.13–20.25 Mg ha –1 ), increasing the CM application rate will not cause a significant variation of HM accumulation in the shoot. The root has a strong retention effect on HMs and prevents them from being transported to the upper organs, which coincides with some previous studies. ,,, …”

“…At R4, the CM0, CM1, and CM2 treatments yielded 1.90, 2.14, and 1.97 times higher shoot biomass and 1.90, 181, and 1.64 times higher root biomass than the CM3 treatment, respectively. It is worth noting that a rapid exponential increase of soybean biomass was detected under CM0, CM1, and CM2 treatments, which agrees with a previous study with respect to the dynamic biomass change of radish and Chinese cabbage . However, the CM3 treatment (20.25 Mg ha –1 ) greatly inhibited biomass production.…”

“…Although Cd–Zn interactions have been commonly observed, findings are contradictory because both depressing and enhancing effects of each metal have been reported. Cd can be taken up by plant roots via a ZRT- and IRT-like protein and Nramp families of Zn . In this study, the results illustrated an increasingly available Cd:Zn ratio in the rhizosphere that caused an antagonistic effect between Cd and Zn and inhibited root Zn uptake.…”

Epidemiological Study on Metal Pollution of Ningbo in China

“…In addition, the relatively high PI of Cd in vegetables also indicated Cd contamination. The dynamic uptake of metals varies at different growth points for different vegetables [ 27 ]. Our results also show that the accumulations of different metals in different vegetables or rice are different.…”

Metal Exposure Risk Assessment for Tree Sparrows at Different Life Stages via Diet from a Polluted Area in Northwestern China

“…Soil samples were digested with a mixture of HCl, HNO 3 , HClO 4 , and HF, whereas biological samples were treated with HNO 3 and HClO 4 (Ai et al 2016). Metal concentrations were determined using an atomic absorption spectrophotometer (Analytik Jena, ZEEnit 700 P, Germany).…”