|WANG, QIUXIA - Chinese Academy Of Agricultural Sciences|
|CAO, AOCHENG - Chinese Academy Of Agricultural Sciences|
|YAN, DONGDONG - Chinese Academy Of Agricultural Sciences|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2016
Publication Date: 3/8/2016
Citation: Wang, Q., Gao, S., Wang, D., Spokas, K.A., Cao, A., Yan, D. 2016. The mechanisms for 1,3-dichloropropene dissipation in biochar-amended soils. Journal of Agricultural and Food Chemistry. 64(12):2531-2540.
Interpretive Summary: The potential of using biochars to reduce detrimental emissions from soil fumigation depends largely on the mechanisms or processes in deactivating fumigants. This research determined the role of adsorption and degradation in fumigant 1,3-dichloropropene disappearance with six biochar products. All biochars showed stronger adsorption (49-93%) than degradation (7-42%) although these were affected by biochar properties and soil/environmental factors. The use of biochars will lead to emission reduction but also tend to increase fumigant residence time in soil. Thus the fate of adsorbed fumigant onto biochar and impact on pest control or the environment need further investigation.
Technical Abstract: Biochar has the potential to reduce fumigant emissions to protect air quality; however, the mechanisms are not fully understood. The objective of this study was to determine effects of biochar properties, amendment rate, soil moisture, temperature, and soil type on degradation and adsorption characteristics of 1,3-dichloropropene (1,3-D) isomers in biochar-amended soils. Laboratory incubation experiments were conducted to assess 1,3-D degradation rate and adsorption capacity under various controlled conditions. Biochar amendments significantly decreased 1,3-D degradation rates, but this decrease was a function of the biochar type. The half-lives of 1,3-D were extended from 2.5 to 35 times following a 1% biochar amendment. This biochar effect, however, was reduced by increasing soil moisture content and temperature, as well as amendment rate. The effects of sterilization on 1,3-D degradation in biochar-amended soils were much less than in un-amended soil suggesting the importance of abiotic pathways, and 49-93% adsorption and 7-42% chemical degradation were determined for biochar-fumigant reactions. Biochar properties affecting 1,3-D dissipation were complex with potential interactions between surface area (SSA), pH, water content, C content, and feedstock. From this work, the air dried biochar water content can serve as an important predictor to estimate 1,3-D dissipation, because it was highly correlated with 1,3-D adsorption capacity. The results suggest that biochars with high adsorption capacity and/or degradation potential can facilitate emission control in soil fumigation, but the fate of the adsorbed fumigant requires further examination on potential environmental impact.