Variations in Cadmium Concentrations in Rice and Oxidation-Reduction Potential at the Soil Surface with Supplementation of Fermented Botanical Waste-based Amendment in Large-scale Farmland

Abstract

We monitored the relationship between cadmium (Cd) concentration uptake of rice and oxidationreduction potential (ORP) at the soil surface with supplementation of fermented botanical wastebased amendment (FBWA), an organic fertilizer prepared from woody and food wastes. This study was carried out for 3 years in the western part of Jiangsu Province, China. It was found that the Cd concentration taken up by rice was correlated to a decreased ORP of the cultivated soil. The yield of rice was ~1.20 times higher than that of the control plot. The effects of reducing Cd content in rice and increasing rice yield remained for 2 years after FBWA application. Finally, Cd in the soil was immobilized by adsorption to FBWA or the decomposed products. The ORP measurement during rice cultivation might be a key index to predict the suppression effect of Cd uptake into the rice or limitation of the sustainable effect by the FBWA.