Basal and Foliar Treatment using an Organic Fertilizer Amendment Lowers Cadmium Availability in Soil and Cadmium Uptake by Rice on Field Micro-Plot Experiment Planted in Contaminated Acidic Paddy Soil

In the present study, field micro-plot experiments were conducted to investigate the basal and foliar application of a tested organic fertilizer amendment (OFA) for decreasing the risk of Cd accumulating in rice. The results showed that applications of OFA significantly increased rice yields in Cd-polluted soil and reduced the level of Cd in rice plants, especially in rice grain. In addition, three application methods of OFA were investigated (single basal application (B1, B2, and B3), combined basal application (+LM, +D, and +Z), and foliar application (F1, F2)). Treat B, F, +LM, +D were all higher than control on rice yield with 25.03, 28.05, 30.61, 22.50 g pot(-1) on average, respectively. Among which, rice cadmium depress to 0.33 mg kg(-1) in foliar application is considered to be a more efficient and economical method of heavy metal remediation. The mechanism of foliar application to alleviate the accumulation of Cd in brown rice may be related to the probable Cd sequestration in the leaves and straws. And the doses of the foliar application were 2.25-3.75 kg hm(-2), approximately 1.0-2.5% of the basal application amount yet with more effect (0.10 mg kg(-1) more than single basal; 0.23 mg kg(-1) more than combined basal) on Cd reduction.