Mechanism of composite passivators to reduce cadmium absorption and accumulation in Chinese cabbage on cadmium-polluted soil

Chemical and Biological Technologies in Agriculture

Table 2 Composite passivator and their addition ratios

Numbering	Composite passivator	Add proportions	Application rate (kg hm⁻²)
CK	0	0	0
T1	Red M (1.5%): Lime (1.5%): PMP (1.5%)	1:1:1	5000
T2	Red M (1.5%): Lime (1.5%): BB (2.5%)	3:3:5	5000
T3	Lime (1.5%): HA (1.5%): Sep (1.5%)	1:1:1	5000
T4	Sep (1.5%): BB (2.5%): Red M (1.5%)	3:5:3	5000
T5	Sep (1.5%): BB (2.5%): PMP (1.5%)	3:5:3	5000

Red M, red mud; PMP, phosphorite powder; BB, biochar; HA, humic acid; Sep, seafoam