Phytoavailability of bound residue of Carbendazim to Chinese cabbage (Brassica campestris ssp.chinensis) coexisted with Superabsorbent polymers

Abstract

Understanding the bioavailability and phytotoxicity of carbendazim (MBc) bound residues (BR) in soils incubated with different Superabsorbent polymer (SAP) amendment on succeeding crops is essential to assess their environmental fate and risks. in our research, we studied the morphological characteristics and 14 c-accumulation of chinese cabbage and released BR in three typical cultivated soils. the plant dry weight was in order of superabsorbent-hydrogels formulations (HMBc) > MBc > MBC and SAP (MBC-SAP) at 35 d in basic soil 3 (S3), with 675.40 ± 29.07 mg/plant.d.w, 575.93 ± 25.35 mg/plant.d.w and 427.86 ± 18.79 mg/plant.d.w. The whole plant accumulated 2-fold more BR when grew in neutral soil 2 (S2) treated with SAP than MBC at 7 d. The root accumulated a greater proportion of 14 c-MBc residue than shoot, with order of MBC-SAP > MBc > HMBC at 21d. The results indicate MBC-BR could be released and accumulated in plant. HMBc promoted the chinese cabbage growth with lowest 14 c accumulation, while MBC-SAP inhibited plant growth with the highest 14 c uptake. the released BR rate was 61.43 ± 3.75% of initial BR in MBC-SAP, with 2-fold higher than MBC and HMBC. It is assumed HMBc could be a potential environmentally friendly measure for rational use of pesticides in future. Pesticides are ubiquitous chemicals in the environment, and are usually used to control crop disease and maintain the products. When pesticides are applied to the field and undergo degradation, their metabolites and they could bind to organic or mineral constituents of soil, and form the non-extractable residue (bound residue) in soil 1. Bound residue (BR) is generally regarded as the soil detoxification process, which involves chemicals could permanently bind to soil matrix, and are no longer bioavailable and bio-accessible to organisms. However, some studies reported that BR could be released via microbial activity and physic-chemical mechanism, and accumulated in living tissues and food webs, posing high threat to human health 2. Han et al. found 14 C-labeled residue of ZJ0273 was released from the BR-amended soil upon planting, and rice seedling took up the 14 C from soil contaminated with compound residues and was inhibited to grow 3. Gao et al. detected a clear uptake, accumulation and translocation of phenanthrene and pyrene by ryegrass, and significant phytoavailabilty of bound-PAH residue 4. Liu et al. also demonstrated that the earthworms accumulated 31.5% of the total radioactivity 14 C-BR-RM 5 after exposure to the BRs of 14 C-CYC. Thus, the food safety issue of agricultural products originated from contaminated soils should be given a public concern. The potential release, bioaccumulation and phytotoxicity of the BR to succeeding non-target organism are always important topics for understanding the environment and human food safety impact of pesticides. Soils are the vital resources that provide life-supporting services of food production, water cleaning and habits for human and wildlife. Intensified agricultural production has deter...

Photocontrolled Release of Carbendazim from Photocaged Molecule

“…in cereals and fruits (33). However, MBC residue in soils can be absorbed by plants and cause residual toxicity (34,35). MBC has been confirmed to induce reproductive, immune and embryonic toxicity in rats, and adversely affect plants, aquatic and soil organisms (36)(37)(38)(39)(40)(41)(42)(43)(44).…”