The effect of high-density polyethylene microplastic and cow manure biochar on carbon,, nitrogen and some biological properties of soil

Document Type : Research Paper

Authors

Department of Soil Sciences and Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran

Abstract

This study investigated the effect of high-density polyethylene microplastic and cow manure biochar on soil organic C, total N and some biological properties affecting carbon and nitrogen cycling. The experiment was conducted in a completely randomized design with treatments including control soil, high-density polyethylene microplastic (2%), biochar (2%) and a mixture of microplastic (2%) and biochar (2%) in three replicates. The soil samples were incubated for 60 days at laboratory temperature and 70% field capacity. The findings indicated that biochar and the combination of biochar and microplastic increased soil organic C and total N. The use of microplastic and biochar in soil either alone or in combination, caused a significant decrease in soil microbial respiration. Experimental treatments did not have a significant effect on microbial biomass nitrogen (p>0.05). Microplastic had no significant effect on microbial biomass carbon but biochar and biochar with microplastic additions caused a significant increase by 73.51 and 78.66%, respectively. similar trend was observed in the ratio of microbial biomass carbon to microbial biomass nitrogen. Microplastic did not have a significant effect on urease activity, net nitrogen mineralization and nitrification, but biochar with microplastic application caused an 68.08% increase of urease activity and an insignificant decrease of net nitrogen mineralization and nitrification compared to the control.The results showed that although high-density polyethylene microplastic does not have a significant effect on most of the measured soil parameters, biochar can affect the carbon and nitrogen cycling in uncontaminated andmicroplastic-contaminated soil by altering C and N content aswellas biological properties.

Keywords

Main Subjects