An integrated three-crop rotation of oilseed rape−rice−rice enables the safe utilization and sustainable remediation of Cd-contaminated farmland

A sustainable strategy for cadmium (Cd)-contaminated farmland was developed using a rape−rice−rice rotation system. This method combines early maturing and high Cd-accumulating rape variety with low Cd-accumulating rice varieties and alkaline Si-rich fertilizer. Field experiments compared different planting patterns: single-season rice (SR), oilseed rape−rice rotation (OR), rice-rice rotation (RR), modified oilseed rape-rice rotation (MOR), and integrated three-crop rotation (MORR). MORR significantly reduced Cd content in rice grains, boost total crop yield, and enhanced soil Cd removal. It achieved a comprehensive evaluation index of 0.99, safe crop production over three seasons, a soil Cd removal rate of 87.338 g/ha/yr, and economic benefits of 34,915 CNY·ha −1 . Simulations based on the Cd input-output balance showed MORR cleaned soil Cd below standards in 12 years, outperforming the 15 years required by the Sedum alfredii and peanut rotation (SP). MORR minimized health risks from Cd exposure, balancing safe production, soil remediation, and farmer income, offering a viable solution for sustainable use of Cd-contaminated farmland. • A rape-rice-rice rotation by integrating varieties and amendment (MORR) enables more sustainable restoration and production. • MORR has the highest comprehensive evaluation index in terms of safety production, economic benefit and soil Cd removal. • Under 4 remediation scenarios, MORR minimizes human health risks and cleans soil Cd within 12 years. • Synchronous atmospheric deposition pollution control and straw resource utilization further improve the application potential of MORR.