Contacts Centre for Environmental Biology

Gerardo Ojeda

Main Research Interests

- Domain of specialization: Influence of sewage sludge on soil physical, chemical and biological properties. Addition of sewage sludge to soil modifies some soil properties, when its use increases the soil organic matter content, rising the soil nutrient levels, increasing soil microbial and plant activity, and improving soil aggregate stability and/or soil water retention. Sludge on soil stabilized aggregates against mechanical disaggregation during wetting. Organic matter can decrease the wettability of soil aggregates, improving their stability. Soil aggregation can influence the accessibility of substrate to microbes and fauna and the rates of diffusion of reactants. Diffusivity of contaminants can be affect by soil aggregation. Soil water retention plays a main role in contaminant transport and mineralization processes in soil. Water retention curve controls soil wetting/drying conditions and as a consequence, the soil biological activity. Organic carbon effects on soil water retention are mediated by changes in bulk density and/or pore surface.
- Present investigation interests: Gain knowledge about: (i) the influence of soil physical properties on the degradation and toxicity of the ethoxylated nonylphenols (NPE) in sludge amended soils, (ii) the influence of soil physical properties on the metal bioavalavility of metals in a soil amended with sewage sludge which was produced by surface finishing industry activities and (iii) the effects of different types of biochar on soil aggregate stability, wettability and water retention of soil.


Academic Qualifications

- 2008: Post-doctoral position, IMAR Instituto do Mar, Universidade de Coimbra.

- 2005: PhD in Biology, Universitat Autònoma de Barcelona (Spain).


Recent Publications

Ojeda G., Patrício J., Navajas H., Comellas L., Alcañiz J.M., Ortiz O., Marks E., Natal-da-Luz T. & Sousa J.P. 2013. Effects of nonylphenols on soil microbial activity and water retention. Applied Soil Ecology 64:77-83.

Natal-da-Luz T., Ojeda G., Costa M., Pratas J., Lanno R.P., Van Gestel C.A.M. & Sousa J.P. 2012. Short-term changes of metal availability in soil I: Comparing sludge amended and metal-spiked soils. Archives of Environmental Contamination and Toxicology 63(2):199-208.

Ortiz O., Ojeda G., Espelta J.M. & Alcañiz J.M. 2012. Improving substrate fertility to enhance growth and reproductive ability of a Pinus halepensis Mill. afforestation in a restored limestone quarry. New Forests 43(3):365-381.

Natal-da-Luz T., Ojeda G., Pratas J., Van Gestel C.A.M. & Sousa J.P. 2011. Toxicity to Eisenia andrei and Folsomia candida of a metal mixture applied to soil directly or via an organic matrix. Ecotoxicology and Environmental Safety 74:1715-1720.

Natal-da-Luz T., Ojeda G., Costa M., Pratas J., LAnno R.P., Van Gestel C.A.M. & Sousa J.P. 2011. Short-term changes of metal availability in soil. II: The influence of earthworm activity. Applied Soil Ecology 49:178-186.

Ojeda G., Mattana S., Bonmati M., Woche S.K. & Bachmann J. 2011. Soil wetting-drying and water-retention properties in a mine-soil treated with composted and thermally-dried sludges. European Journal of Soil Science 62:696–708.

Ojeda G., Mattana S., Alcañiz J.M., Marando G., Bonmatí M., Woche S.K. & Bachmann J. 2010. Wetting process and soil water retention of a minesoil amended with composted and thermally dried sludges. Geoderma 156:399–409.

Tarrasón D., Ojeda G., Ortiz O. & Alcañiz J.M. 2010. Effects of Different Types of Sludge on Soil Microbial Properties: A Field Experiment on Degraded Mediterranean Soils. Pedosphere 20:681-691.

Ojeda G., Alcañiz J.M. & Le Bissonnais Y. 2008. Differences in aggregate stability due to various sewage sludge treatments on a Mediterranean calcareous soil. Agriculture, Ecosystems & Environment 125:48-56.

Tarrasón D., Ojeda G., Ortiz O. & Alcañiz J.M. 2008. Differences on nitrogen availability in a soil amended with fresh, composted and thermally-dried sewage sludge. Bioresource Technology 99:252-259.

Ojeda G., Tarrasón D., Ortiz O. & Alcañiz J.M. 2006. Nitrogen losses in runoff waters from a loamy soil treated with sewage sludge. Agriculture, Ecosystems & Environment 117:49–56.

Ojeda G., Perfect E., Alcañiz J.M. & Ortiz O. 2006. Fractal analysis of soil water hysteresis as influenced by sewage sludge application. Geoderma 134:386–401.

Ojeda G., Alcañiz J.M. & Ortiz O. 2003. Runoff and losses by erosion in soil amendment with sewage sludge. Land Degradation & Development 14:563–573.

Ongoing Projects

  • 2008 - Pyrogenic organic matter as source of stable carbon in soil and its potential ecotoxicological risks (SOCARRAT: Sequestering Organic CARbon, Recalcitrance And Toxicity).  Ministerio de Educación y Ciencia (Plan Nacional I+D+I 2004-07) ref. AGL2009-12343 (subprograma AGR), Spain.

  • 2011 - use of biochar as a mitigation strategy to climate change and its potential ecotoxicological impact. Ministerio de Ciencia e Invovación, España, CGL2010-15766 (subprograma BOS), Spain.

  • 2010-2014 – “ECOFINDERS – Ecological Function and Biodiversity Indicators in European Soils” EU FP7


Other Information

- Reviewer for the following international journals: (i) Soil Science Society of America Journal, (ii) Geoderma, (iii) Land Degradation and Development, (iv) Acta Scandinava, (v) Scientia Agricola, (vi) Journal of Hazardous Materials, (vii) Waste management, (viii) European Journal of Soil Science.

- Member of the European Geosciences Union from 01-01-2008 to 31-12-2008, 01-04-2012 to 31-03-2013.