Response of cadmium accumulation in rice (Oryza sativa L. cv. SPR1) grown with different organic soil amendments

Rice (Oryza sativa L.) is one of the food crops, which is found to have the great capacity of cadmium (Cd) accumulation. This research was done to investigate the response to Cd accumulation in rice grown with different organic soil amendments (OA), namely soil supplemented with swine manure (SM), cow manure (CM), mixed chicken manure and rice husk (CR), vermicompost (VC), and greensward compost (GC), respectively. Each OA (4% w/w basis) was applied in each treatment with 3 Cd levels at 20, 40, and 60 mg/kg, respectively. The results showed that rice plants were not able to grow in 4% w/w of SM and CM, respectively and wither following 70 d of planting. It was found in the other treatment results that CR, VC, and GC increased harvest index (HI) as well as soil pH while decreasing soil Eh and Cd-HI, compared with the control treatment. All the Cd concentrations did not affect the height, but the wet weight of plants, decreased with increase in Cd concentrations. Regarding the Cd accumulation, it was found that CR is most effective in absorbing Cd in the paddy soils. In terms of Cd uptake, it was found that GC was the only OA that could reduce the Cd uptake in the rice plant parts. The result is consistent with reduction observed in the accumulation of cadmium in stems, leaves, and especially rice grain. Therefore, based on the current finding, both CR and GC soil amendments can be considered for immobilizing Cd in the contaminated fields