Please use this identifier to cite or link to this item:
Title: Evidence for the importance of litter as a co-substrate for MCPA dissipation in an agricultural soil
Authors: Saleh, Omar 
Pagel, Holger 
Enowashu, Esther 
Devers, Marion 
Martin-Laurent, Fabrice 
Streck, Thilo 
Kandeler, Ellen 
Poll, Christian 
Keywords: f 2-Methyl-4- Chlorophenoxyacetic Acid;MCPA;Litter - Deterioration;Toxicity
Issue Date: 2016
Abstract: Environmental controls of 2-methyl-4- chlorophenoxyacetic acid (MCPA) degradation are poorly understood. We investigated whether microbial MCPA degraders are stimulated by (maize) litter and whether this process depends on concentrations of MCPA and litter. In a microcosm experiment, different amounts of litter (0, 10 and 20 g kg−1) were added to soils exposed to three levels of the herbicide (0, 5 and 30 mg kg−1). The treated soils were incubated at 20 °C for 6 weeks, and samples were taken after 1, 3 and 6 weeks of incubation. In soils with 5 mg kg−1 MCPA, about 50 % of the MCPAwas dissipated within 1 week of the incubation. Almost complete dissipation of the herbicide had occurred by the end of the incubation with no differences between the three litter amendments. At the higher concentration (30 mg kg−1), MCPA endured longer in the soil, with only 31 % of the initial amount being removed at the end of the experiment in the absence of litter. Litter addition greatly increased the dissipation rate with 70 and 80 % of the herbicide being dissipated in the 10 and 20 g kg−1 litter treatments, respectively. Signs of toxic effects of MCPA on soil bacteria were observed from related phospholipid fatty acid (PLFA) analyses, while fungi showed higher tolerance to the increased MCPA levels. The abundance of bacterial tfdA genes in soil increased with the co-occurrence of litter and high MCPA concentration, indicating the importance of substrate availability in fostering MCPA-degrading bacteria and thereby improving the potential for removal of MCPA in the environment.
Appears in Collections:Fulltext Publications

Show full item record

Page view(s)

checked on Jun 27, 2024


checked on Jun 27, 2024

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.