José M. Meriles
National Scientific and Technical Research Council
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Featured researches published by José M. Meriles.
Journal of the Science of Food and Agriculture | 2012
Pierluigi Pierantozzi; Catiana Zampini; Mariela Torres; María Inés Isla; Romina A. Verdenelli; José M. Meriles; Damián Maestri
BACKGROUND In the last few years, agricultural uses of waste waters from olive processing-related industries have been gaining interest mainly with a view to composting or bio-fertilizers. The present work examines physico-chemical, toxicological and geno-toxicological properties of three liquid wastes, namely olive mill wastewater (OMWW), olive wet husk and olive brine. The effect of OMWW spreading on soil microbial activity and biomass was also evaluated. RESULTS Data from Artemia salina and Lactuca sativa toxicity tests indicated high levels of lethality, and inhibitory effects on seed germination and seedling growth of all olive wastes. The genotoxicity assays using Allium cepa tests showed contrasting results. At high concentrations, olive wastes caused inhibition or suppression of mitosis. However, they did not produce induced anaphase aberrations. Data on reversion of Salmonella thyphimurium strains using the Ames test indicated that the olive wastes did not present mutagenic activity. Results from the field experiment showed that OMWW at a 500 m(3) ha(-1) had the highest values of both soil microbial activity and biomass after 3 months of the amendment application. CONCLUSION This work adds new data for environmental risk assessment of olive industrial wastes. Direct use of olive wastes for agricultural purposes should be limited owing to their possible chemotoxic, phytotoxic and antimicrobial effects.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2008
N. S. Podio; C. A. Guzmán; José M. Meriles
The short-term effect of three broad spectrum fungicides on microbial activity, microbial biomass, soil ergosterol content, and phospholipid fatty acid (PLFA) profiles was studied. A silty clay loam soil was treated separately with captan, chlorothalonil and carbendazim at three different dosages of each fungicide. Chlorothalonil and carbendazim significantly altered soil microbial activity. However, changes in soil microbial biomass were only observed in soil treated with higher dosages of these fungicides. All dosages of fungicides significantly decreased fungal biomass as estimated by soil ergosterol content. PLFA analysis indicated that there was a shift in PLFA pattern. Higher dosages of all three fungicides decreased a straight-chain PLFA 22:0. In addition, soil treated with carbendazim increased cyclopropyl fatty acids. Compared to untreated soil, higher dosages of both captan and chlorothalonil affected PLFA 10Me 16:0, indicating that these fungicides can reduce actinomycetes population. Finally, our results suggest that application of both captan and chlorothalonil decreased Gram-positive to Gram-negative ratio.
Science of The Total Environment | 2012
Romina A. Verdenelli; Alicia L. Lamarque; José M. Meriles
The use of compost amendments to bioremediate potential organic pollutants in agricultural soils has recently become an increasingly important field of research. Although several fungicides have been extensively used to control a wide range of soil-borne fungal diseases, little is known about the impact of applying these pesticides on the structure and function of microbial communities in soils amended with vermicompost. The aim of this study was to evaluate the effect of a combined treatment of iprodione and vermicompost on soil microbiological parameters under laboratory conditions. The study was carried out on agricultural and grassland soils to identify the effect of iprodione application at field rate (FR) and 10-times FR (10 FR) with and without vermicompost (VCH) on iprodione breakdown, fluorescein diacetate activity (FDA), total fatty acid methyl ester (FAME) profiles, total protein content, and protein profiles by using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Our results indicate that the addition of vermicompost decreased the iprodione breakdown at days 30 and 60 in non-sterilised agricultural soil and at 60 days in sterilised and non-sterilised grassland soil. Independent of vermicompost amended treatments, iprodione was found to mainly alter microbial communities after 30 days of incubation. On day 30, separation between communities treated with iprodione 10 FR and iprodione 10FR + VCH treatments were well defined in both agricultural and grassland soils. Within each soil type, our results showed no difference in the total protein content. However, the protein content in the grassland soil was clearly higher than in the agricultural soil. SDS-PAGE gels revealed that the treatments applied to the agricultural soil using iprodione at the highest dosages (iprodione 10FR and iprodione 10FR+VCH) resulted in an alteration of the band pattern. In conclusion, the experiments revealed that the addition of vermicompost may decrease the breakdown of iprodione in soils. Furthermore, elevated dosages of iprodione may potentially affect the microbial community structure and diversity of the soil, which may lead to the deterioration of soil quality and fertility.
Biocontrol | 2008
Silvina Vargas Gil; José M. Meriles; Ricardo J. Haro; Cristiano Casini; G.J. March
Soil management practices can affect the population dynamics of soil microbial communities. Cultural practices can be adequately combined to benefit natural populations of microorganisms that may have a role in biological control (actinomycetes, Trichoderma spp., and Gliocladium spp.), thus contributing to the management of peanut fungal soilborne diseases in a sustainable manner within ecological boundaries. During six agricultural cycles, rhizosphere soil samples were taken from a field subjected to crop rotation (soybean, peanut, and maize), peanut being under two tillage systems (no till, reduced tillage) with the aim of quantifying populations of soil microorganisms. The incidence of diseases caused by soilborne fungi in peanut was determined at harvest. The highest amount of actinomycetes, Trichoderma spp., and Gliocladium spp. were recorded when maize was the preceding crop. Regarding tillage systems, the populations of the three groups of microorganisms were higher in peanut under no tillage than under reduced tillage. Under these conditions, the lowest incidence of peanut blight (Sclerotinia minor) and root rot (strains of Fusarium solani) was observed, suggesting a possible natural control of peanut soilborne pathogens. The quantification of actinomycetes, Trichoderma spp., and Gliocladium spp. was used as a tool to explore the impacts of different management systems on microbial groups that may be involved in the biological control of soilborne diseases, with the aim of combining those practices that improve native populations of possible beneficial microorganisms. This manipulation can provide sustainable management strategies in the control of soilborne diseases, avoiding the use of artificial inoculations of microorganisms, and reducing agrochemical application.
Biological Agriculture & Horticulture | 2008
José M. Meriles; S. Vargas Gil; Ricardo J. Haro; G.J. March; C. A. Guzmán
ABSTRACT A study was carried out to determine the short-term effects of glyphosate and crop residues on the population dynamics of soil-borne fungi under field conditions. Field experiments were conducted during two growing seasons. The assays were done in plots that were subjected to a peanut (Arachis hypogaea)-corn (Zea mays)-soyabean (Glycine max) rotation system with two sequences: corn-soyabean-peanut and soyabean-corn-peanut. Soil samples were randomly collected from a peanut-corn-soyabean rotation field located at Córdoba province (Argentina) in order to quantify native populations of Fusarium, Pythium, Trichoderma, Gliocladium and culturable total fungi populations. Independently of the present crop, the highest population of Trichoderma and Gliocladium were recorded in soil with corn residue. Pythium populations increased after glyphosate treatment. Trichoderma, Gliocladium and culturable total fungi populations were not affected by glyphosate applications. Information on the actual time and duration of population responses of various important soil-borne fungi after glyphosate treatment is currently limited since it is dependent on numerous parameters such as soil condition, type of hosts involved and soil microbial interactions. The use of corn residue appeared as an interesting alternative to increase the population of potential antagonistre fungi, and reduce crop diseases; therefore more field research along this line is clearly needed.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2013
Pierluigi Pierantozzi; Mariela Torres; Romina A. Verdenelli; María Basanta; Damián Maestri; José M. Meriles
The purpose of this work was to investigate the effects of spreading olive oil mill wastewater (OMWW) on soil biochemical parameters and olive production in an organically managed olive orchard. The experiment was carried out with three different doses of OMWW (80, 160 and 500 m3 ha−1) and a control (untreated soil). Three samplings were done at 10, 30 and 90 days after the administration of the byproduct. OMWW application differentially modified the biochemical properties of the soil analyzed. Organic matter, organic carbon, total nitrogen and extractable phosphorus soil contents increased proportionally with each increasing dose. The values of these parameters decreased gradually with time. Total microbial activity was altered and the OMWW 500 m3 ha−1 treatment proved to be the most active when compared with the other applied doses. OMWW agricultural application also modified the structure of soil microbial communities, particularly affecting Gram positive and negative bacteria, while fungal biomass did not show consistent changes. Although there was a salinity increase in the treated soil, especially at the highest dose, the productive parameters analyzed (fruit and oil tree−1) were not affected. In light of the obtained results, we consider that low dose of OMWW could be considered an alternative farming practice for semiarid regions.
Acta Agriculturae Scandinavica Section B-soil and Plant Science | 2013
Romina A. Verdenelli; Cinthia Conforto; Carolina Pérez-Brandan; D. Chavarría; A. Rovea; Silvina Vargas-Gil; José M. Meriles
The effect of mineral fertilizer application on soil microbial community was investigated in a conservation agriculture system. The aim of this work was to evaluate how mineral fertilization with nitrogen (N), phosphorus (P), sulfur (S), and micronutrients (M) affects microbial community structure and function. A 10-year experiment, conducted on a typic Hapludoll using six mineral fertilizer treatments (control, CK; PS; NS; NP; NPS; and NPSM) was evaluated in central Argentina. Microbial community structure and function were characterized by phospholipid fatty acids and community-level physiological profiles, respectively. Soil microbial metabolic activity was determined by monitoring microbial respiration, fluorescein diacetate activity (FDA), dehydrogenase activity and phosphatase activity (PHA). NPS and NPSM treatments showed higher total microbial biomass and gram-positive and gram-negative bacteria, but lower fungal biomass than the remaining treatments. Fertilizer treatments without S (CK and NP) showed lower carbon source utilization and Shannon index than the other treatments. In addition, both FDA and PHA significantly increased under NPSM. An integrated PC analysis indicated that sensitive bioindicators were significantly associated with three carbon sources, one metabolic parameter, and six fatty acid bioindicators. These results provide information about the importance of balanced fertilization with P, N, S, and M in promoting microbial biomass, metabolic activity, and functional diversity.
Soil & Tillage Research | 2009
José M. Meriles; S. Vargas Gil; Cinthia Conforto; G. Figoni; E. Lovera; G.J. March; C. A. Guzmán
European Journal of Soil Biology | 2011
S. Vargas Gil; José M. Meriles; Cinthia Conforto; M. Basanta; V. Radl; A. Hagn; M. Schloter; G.J. March
Food Control | 2012
José S. Dambolena; Abel G. López; José M. Meriles; Héctor R. Rubinstein; Julio A. Zygadlo