scholarly journals Direct and legacy effects of plant-traits control litter decomposition in a deciduous oak forest in Mexico

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5095 ◽  
Author(s):  
Bruno Chávez-Vergara ◽  
Agustín Merino ◽  
Antonio González-Rodríguez ◽  
Ken Oyama ◽  
Felipe García-Oliva
Keyword(s):  
Microbial Community ◽  
Mass Loss ◽  
Microbial Activity ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Soil Microbial Community ◽  
Litter Quality ◽  
Metabolic Capacity ◽  
Soil Microbial ◽  
Decomposition Stage

Background Litter decomposition is a key process in the functioning of forest ecosystems, because it strongly controls nutrient recycling and soil fertility maintenance. The interaction between the litter chemical composition and the metabolism of the soil microbial community has been described as the main factor of the decomposition process based on three hypotheses: substrate-matrix interaction (SMI), functional breadth (FB) and home-field advantage (HFA). The objective of the present study was to evaluate the effect of leaf litter quality (as a direct plant effect, SMI hypothesis), the metabolic capacity of the microbial community (as a legacy effect, FB hypothesis), and the coupling between the litter quality and microbial activity (HFA hypothesis) on the litter decomposition of two contiguous deciduous oak species at a local scale. Methods To accomplish this objective, we performed a litterbag experiment in the field for 270 days to evaluate mass loss, leaf litter quality and microbial activity in a complete factorial design for litter quality and species site. Results The litter of Quercus deserticola had higher rate of decomposition independently of the site, while the site of Quercus castanea promoted a higher rate of decomposition independently of the litter quality, explained by the specialization of the soil microbial community in the use of recalcitrant organic compounds. The Home-Field Advantage Index was reduced with the decomposition date (22% and 4% for 30 and 270 days, respectively). Discussion We observed that the importance of the coupling of litter quality and microbial activity depends on decomposition stage. At the early decomposition stage, the home-advantage hypothesis explained the mass loss of litter; however, in the advanced decomposition stage, the litter quality and the metabolic capacity of the microbial community can be the key drivers.

scholarly journals Soil Microbial Community Changes in a Field Treatment with Chlorotoluron, Flufenacet and Diflufenican and Two Organic Amendments

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1166
Author(s):  
María José Carpio ◽  
Carlos García-Delgado ◽  
Jesús María Marín-Benito ◽  
María Jesús Sánchez-Martín ◽  
María Sonia Rodríguez-Cruz
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Microbial Activity ◽  
Soil Microbial Community ◽  
Organic Amendments ◽  
Herbicide Application ◽  
Amended Soils ◽  
Soil Microbial ◽  
Unamended Soil ◽  
Over Time

The soil microbial activity, biomass and structure were evaluated in an unamended (S) and organically amended soil treated with two commercial formulations of the herbicides chlorotoluron (Erturon®) and flufenacet plus diflufenican (Herold®) under field conditions. Soils were amended with spent mushroom substrate (SMS) or green compost (GC). Soil microbial dehydrogenase activity (DHA), biomass and structure determined by the phospholipid fatty acid (PLFA) profiles were recorded at 0, 45, 145, 229 and 339 days after herbicide treatment. The soil DHA values steadily decreased over time in the unamended soil treated with the herbicides, while microbial activity was constant in the amended soils. The amended soils recorded higher values of concentrations of PLFAs. Total soil microbial biomass decreased over time regardless of the organic amendment or the herbicide. Herbicide application sharply decreased the microbial population, with a significant modification of the microbial structure in the unamended soil. In contrast, no significant differences in microbial biomass and structure were detected in S + SMS and S + GC, untreated or treated with herbicides. The application of SMS and GC led to a significant shift in the soil microbial community regardless of the herbicides. The use of SMS and GC as organic amendments had a certain buffer effect on soil DHA and microbial biomass and structure after herbicide application due to the higher adsorption capacity of herbicides by the amended soils.

scholarly journals Soil Microbial Community Response to Compost Addition to Nicosulfuron Contaminated Soil

2018 ◽  
Vol 6 (4) ◽  
pp. 49
Author(s):  
Solomon A. Adejoro ◽  
Ajoke C. Adegaye ◽  
Doyinsola S. Sonoiki
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Microbial Activity ◽  
Soil Microbial Community ◽  
Organic Fertilizer ◽  
Community Response ◽  
Herbicidal Activity ◽  
Microbial Biomass C ◽  
Mineral Fertilizers ◽  
Soil Microbial

The toxicity of nicosulfuron to none target organisms is its downside, which has generated concerns about the herbicide in spite of its high herbicidal activity. Practices that would facilitate accelerated degradation of this herbicide will certainly be complementary to its use. A completely randomized design laboratory incubation experiment was carried out to examine the potentials of organic and mineral fertilizers to stimulate microbial activities in soil under the influence of the nicosulfuron herbicide. Soil contaminated with the field rate of nicosulfuron was separately amended with compost and NPK mineral fertilizer, and the treated samples were incubated for 56 days at room temperature. Soil microbial activity and microbial biomass C were measured in dynamics for the period of incubation. Eco-physiological quotients were also computed at the end of incubation to determine responses of soil microbes at the community level to the treatments. Application of nicosulfuron alone was found to repress both microbial biomass and microbial activity. Addition of fertilizer however caused these parameters to increase especially during the first 28 days after treatment application. The microbial metabolic quotient was raised by the soil amendments shortly after application with the exemption of NPK treated soil. However, only the soil samples in which compost was present lowered qCO2 at the termination of the experiment. NIC-COMP and NIC-NPK respectively raised and lowered the soil carbon mineralization quotient (qM) measured at the end of incubation. The soil microbial community was also found to be positively affected by the addition of fertilizers as indicated by the Cmic: Corg ratio and the microbial biomass change rate quotient (qC). It was therefore concluded that though the nicosulfuron herbicide at the field recommended rate has potentials to negatively affect the soil microbial community, application of organic fertilizer may help the soil to regain its microbial competence through enhanced degradation engendered by biostimulation of native microorganisms.

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