Effects of soil factors on dimethyl disulfide desorption and the risk of phytotoxicity to newly-planted seedlings

Xiujun Tang; Aocheng Cao; Yi Zhang; Xinhua Chen; Anmin Guo; Baoqiang Hao; Jin Xu; Wensheng Fang; Dongdong Yan; Yuan Li; Haiqun Cao; Qiuxia Wang

doi:10.1016/j.ecoenv.2023.115313

Effects of soil factors on dimethyl disulfide desorption and the risk of phytotoxicity to newly-planted seedlings

Ecotoxicol Environ Saf. 2023 Aug 7:262:115313. doi: 10.1016/j.ecoenv.2023.115313. Online ahead of print.

Authors

Xiujun Tang¹, Aocheng Cao², Yi Zhang², Xinhua Chen², Anmin Guo², Baoqiang Hao², Jin Xu³, Wensheng Fang², Dongdong Yan², Yuan Li², Haiqun Cao⁴, Qiuxia Wang⁵

Affiliations

¹ School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China; State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, Hefei, Anhui Province 230036, China.
² State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
³ Beijing Agricultural Technology Extension, Beijing 100029, China.
⁴ School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China; Key Laboratory of Agri-products Quality and Biosafety (Anhui Agricultural University), Ministry of Education, Hefei, Anhui Province 230036, China.
⁵ State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China. Electronic address: wqxcasy@163.com.

PMID: 37556960
DOI: 10.1016/j.ecoenv.2023.115313

Abstract

Dimethyl disulfide (DMDS) is a relatively new soil fumigant used in agro-industrial crop production to control soil-borne pests that damage crops and reduce yield. The emissions of DMDS after fumigation reduce soil concentrations thus reducing the risk of phytotoxicity to newly planted crops. However, the factors affecting the desorption of DMDS from soil are unclear. In our study, the desorption characteristics of DMDS from soil were measured in response to continuous ventilation. The degradation of DMDS in soil was examined by thermal incubation. The phytotoxic response of newly-planted cucumber (Cucumis sativus) seedlings to DMDS residues was measured by a sand culture experiment. The results showed DMDS desorption and degradation rates fit a first-order model; that 92% of the DMDS desorption occurred in the first hour after fumigant application; and that residue concentrations in the soil at the end of the ventilation period were unlikely to be phytotoxic to newly-planted cucumber seedlings. By the third day of ventilation, the average desorption rate (ADR) of DMDS in Wenshan soil was 4.0 and 3.6 times, respectively, faster than that in Shunyi and Suihua soils and the ADR of DMDS in soil decreased by 40.0% when the soil moisture content increased from 3% to 12% (wt/wt). Moreover, within one hour of ventilation, the ADR of DMDS in soil decreased by 20.1% when the soil bulk density increased from 1.1 to 1.3 g cm^-3. The degradation of DMDS in soil, however, was mostly influenced by soil type and moisture content. A slow degradation rate resulted in a high initial desorption concentration of DMDS in soil. Our results indicated that DMDS desorption from soil in response to continuous ventilation was affected by the soil type, moisture content and bulk density. Rapid degradation of DMDS in soil will lower the risk of phytotoxic residues remaining in the soil and reduce emissions during the waiting period. Acceleration of emissions early in the waiting period by managing soil moisture content or increasing soil porosity may shorten the duration of emissions. Alternatively, soil extraction technology could be developed to recover and reduce fumigant emissions.

Keywords: Desorption; Dimethyl disulfide; Phytotoxicity; Soil; Volatilization.