Applying Tire Rubber Ash Enriched Cow Manure as a Useful Way to Decrease Canola Cd Uptake in a Polluted Soil

Abstract

Background: Cadmium (Cd) is a toxic heavy metal that affects plant growth and human health. Therefore, it is necessary to reduce its concentration. Objectives: This research was done to investigate the role of tire rubber ash enriched cow manure application to reduce Cd uptake by canola. Methods: Treatments were consist of applying three levels of cow manure (0, 10 and 20 t ha-1), two levels of tire rubber ash (0 and 200 kg ha-1) in a Cd polluted soil (0, 5, 10 and 15 mg Cd (kg soil)-1). The Cd and Zinc (Zn) concentration of canola was measured using atomic absorption spectroscopy. This research was done as a factorial experiment in the layout of completely randomized block design with three replications. Results: Applying 20 t ha-1 tire rubber ash enriched cow manure in 10 mg Cd (kg soil)-1 polluted soils decreased root Cd concentration by 30.1%, while the root Zn concentration was increased by 17%. In addition, applying the above amount of organic amendment in 15 mg Cd (kg soil)-1 polluted soils decreased grain Cd concentration by 45.7%, while the grain Zn concentration was increased by 27%. In addition, the aboveground biomass of plant was also increased by 30%. Conclusions: The results of this study showed that enrichment of cow manure with tire rubber ash can decrease plant Cd concentration in Cd polluted soils (interaction effects of Cd and Zn), that is a positive point in environmental research. However, the type of plant and amount of pollution could not be ignored.

Effect of Applying Sunflower Residues as a Green Manure on Increasing Zn Concentration of Two Iranian Wheat Cultivars in a Pb and Cd Polluted Soil

“…It may be related to the interaction effect of heavy metals and nutrient elements that is mentioned by researchers [1,28]. Baghaie et al (2018) investigated the effect of applying tire rubber ash enriched cow manure as a useful way to decrease canola Cd uptake in a polluted soil and concluded that the application of cow manure decreased and increased soil Cd and Zn availability, respectively [11]. The results of Tabarteh et al (2017) about the role of organic amendment application on decreasing and increasing soil heavy metal and nutrient availability, respectively, that confirms our results clearly [29].…”

“…After plants growth to nearly 3 centimeters, 4 vigorous plants were selected and remained in the pots. After 70 days from the beginning of the experiment [10], the sunflower plant was harvested and the shoot and root Zn concentration was measured [11] (Table 2).…”

“…After that, the samples were dried at 75 °C for 48 h and ground. The samples were placed at 550 °C for about 4 h and the ash was dissolved in HCl 2 M. Concentrations of Zn, Pb and Cd of the digested solutions were determined [11] by atomic absorption spectroscopy (PerkinElmer model 3030). The soil heavy metal availability was measured according to the Lindsay method [12].…”

“…The soil heavy metal availability was measured according to the Lindsay method [12]. The soil pH was measured in 1:2.5 (V/W) suspension using a pH meter (Model EA940, Orion, USA) that was standardized with the three reference buffers (4, 7 and 9.2) [11]. Electrical conductivity (EC) was determined by conductivity meter (Model, AZ 86503).…”