Enhanced Cd accumulation and yield in peanut (Arachis hypogaea L.) via combined chlorine-containing fertiliser application

Peanut (Arachis hypogaea L.) is an essential oilseed crop, exhibiting a pronounced capacity for cadmium (Cd) accumulation. Therefore, the application of a fertiliser that enhances the efficient uptake of Cd by peanuts is crucial for remediating Cd-contaminated soils. Herein, the effects and mechanisms of chlorinated fertiliser treatments (NH4Cl and KCl) at five proportions (0 %, 10 %, 50 %, 100 % and 136 %) were investigated for remediating Cd-contaminated soil in peanut cultivation. Chloride addition not only enhanced the biomass of peanut shells and kernels, reflecting a positive fertiliser effect, but also promoted Cd accumulation in plant tissues, suggesting a notable environmental interaction. This was attributed to the rise in water-soluble Cd concentration in the soil and the Cd concentration in the soluble fraction, ethanol-extracted form and water-extracted form in the roots, shoots and leaves. These combined effects of chloride treatment collectively enhanced Cd translocation to the aerial parts of peanuts. Furthermore, treatment with 136 %Cl exhibited the optimum remediation effect, resulting in a drastic increase of 36.11 % in peanut shell biomass and 33.74 % in kernel biomass. Additionally, Cd accumulation in peanuts increased by 83.98 %. These findings enhance the potential yield of peanut oil for industrial use and establish the foundation for environmentally sustainable and economically efficient agricultural practices. [Display omitted] •Chlorine-containing fertilisers were effective in Cd accumulation by peanut.•Cl− significantly increased the economical yield of peanut.•Cl− increased the bioavailability of Cd in the soil and enhanced Cd translocation.•Cl− increased the Cd concentration of soluble fractions and active forms in peanut.