Zinc oxide nanoparticles affect carbon and nitrogen mineralization of Phoenix dactylifera leaf litter in a sandy soil.
We investigated the impact of zinc oxide nanoparticles (ZnO NPs; 1000mgkg-1soil) on soil microbes and their associated soil functions such as date palm (Phoenix dactylifera) leaf litter (5gkg-1soil) carbon and nitrogen mineralization in mesocosms containing sandy soil. Nanoparticles application in litter-amended soil significantly decreased the cultivable heterotrophic bacterial and fungal colony forming units (cfu) compared to only litter-amended soil. The decrease in cfu could be related to lower microbial biomass carbon in nanoparticles-litter amended soil. Likewise, ZnO NPs also reduced CO2emission by 10% in aforementioned treatment but this was higher than control (soil only). Labile Zn was only detected in the microbial biomass of nanoparticles-litter applied soil indicating that microorganisms consumed this element from freely available nutrients in the soil. In this treatment, dissolved organic carbon and mineral nitrogen were 25 and 34% lower respectively compared to litter-amended soil. Such toxic effects of nanoparticles on litter decomposition resulted in 130 and 122% lower carbon and nitrogen mineralization efficiency respectively. Hence, our results entail that ZnO NPs are toxic to soil microbes and affect their function i.e., carbon and nitrogen mineralization of applied litter thus confirming their toxicity to microbial associated soil functions.
Center of Excellence in Environmental Studies, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia; Department of Environmental Sciences, COMSATS Institute of Information Technology, 61100, Vehari, Pakistan. Electronic address: mimurad@kau.edu.sa.
Muhammad Imtiaz
MI
Rashid
Department of Environmental Sciences & Engineering, Government College University, 38000, Faisalabad, Pakistan.
Tanvir
T
Shahzad
Department of Environmental Sciences, COMSATS Institute of Information Technology, 61100, Vehari, Pakistan.
Muhammad
M
Shahid
Center of Excellence in Environmental Studies, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia; Department of Chemistry, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia.
Iqbal M I
IM
Ismail
Department of Environmental Sciences, COMSATS Institute of Information Technology, 61100, Vehari, Pakistan.
Ghulam Mustafa
GM
Shah
Center of Excellence in Environmental Studies, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia; Department of Environmental Sciences, King Abdulaziz University, Jeddah 2158, Saudi Arabia.
Talal
T
Almeelbi
D058491:Bacterial Load; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000032:analysis; D053768:Metal Nanoparticles / Q000633:toxicity*; D009584:Nitrogen / Q000378:metabolism*; D065749:Phoeniceae / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D015034:Zinc Oxide / Q000633:toxicity*
D012987:Soil; D012989:Soil Pollutants; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen; D015034:Zinc Oxide
Ecotoxicology; Metabolic quotient; Microbial biomass carbon; Nutrient mineralization; Soil functions