Abstract:
The "Huaxing dan 88" maize variety was used to explore the effect of different passivation material combinations and dosages on Cd and Pb absorption by maize and facilitate safe crop production in heavy metal-contaminated farmland. This study also used field experiments to examine the impact of "Jiangge ling" foliar inhibitor (JGL), organic fertilizer (YJF), humic acid (FZS), and soil heavy metal passivator (DHJ) spraying and the different dosage combinations on the biological traits of maize, the Cd and Pb levels, the bioconcentration factor (BCF), and translocation factor (TF). The BCF of the Cd and Pb in the maize grains was used to calculate the soil Cd and Pb risk threshold (
T) as a resistance evaluation index. The results show that the nine resistance control measures increased the yield by 14.4% to 32.3% compared with CK, with the yield increasing ability exhibiting an order of JGL<YJHJ<YJF1<YJHJ
+<YJF1
+<YJF2<YJZS<YJF2
+<YJZS
+. The Cd and Pb levels and Cd BCF and Pb BCF values in the maize grains decreased from 31.0% to 65.5%, 18.2% to 59.1%, 33.2% to 68.7%, and 16.8% to 57.6%, respectively, compared with CK. The control effect of Cd and Pb was JGL>DHJ>YJF1>DHJ
+>YJF1
+>YJF2>FZS>YJF2
+>FZS
+. The Cd and Pb content and enrichment were highest in the roots of the maize and lowest in the grains. The stem-leaf transport ability of Cd and Pb was the strongest, while the root-stem capacity was the weakest. Field experiments confirmed that the yield and Cd and Pb control effect of the maize exposed to the 10 treatments were FZS
+>YJF2
+>FZS>YJF2>YJF1
+>DHJ
+>YJF1>DHJ>JGL>CK. The soil
TCd and
TPb of the tested maize were between 11.0-23.1 mg·kg
-1 and 109.9-218.0 mg·kg
-1, respectively. Therefore, FZS is recommended as a passivation material in the maize production area under mild to moderate Cd pollution since it has displayed the best yield increase and Cd and Pb resistance effect, and FZS
+ is recommended as a combination measure which has exhibited the best yield increase and Cd and Pb resistance effect in the maize production area under severe Cd pollution.