Novel results of the use of biochar as soil amendment in Mediterranean agriculture

Researchers of the IRNAS-CSIC led by J.M. De la Rosa and H. Knicker have recently published novel results concerning the relationships between biochar properties and agronomic productivity under Mediterranean climate conditions.

Biochar is a carbonaceous material obtained from the pyrolysis of biomass. The application of biochar to soil is being proposed as a novel approach to establish a significant long-term sink for atmospheric carbon dioxide in terrestrial ecosystems. The role of biochar in carbon sequestration as well as in reducing the emission of greenhouse gases, and improving soil fertility is increasingly being recognised and has led to the recommendation of biochar as an amendment of soils. In addition, biochar offers a simple, sustainable tool for managing agricultural and urban wastes by turning it into value products. The attraction and interest of “Biochar systems” is that they may provide solutions that tackle environmental and agricultural problems simultaneously. However, prior to sharpen this mitigation and waste management tool “Biochar systems”, several issues need to be solved and constituted the major goals of the research presented.

  1. There are a number of detailed studies describing short term effects of biochar and most of them are exclusively focused on (sub)tropical regions. Consequently, there is a lack of knowledge about the real carbon sequestration potential of biochar amended soils under Mediterranean climate conditions.

  2. The quality of biochar is highly dependent on the feedstock and the production process. Thus produced biochars need to be characterized before application to predict its properties and customize them in accordance with itsuse.

This study demonstrated that biochar can act as a soil conditioner enhancing plant growth in typical Mediterranean agricultural soils by supplying and, more importantly, retaining nutrients and by improving soil physical and biological properties. However, the effectiveness of biochar in enhancing plant fertility is not only a function of soil type, climate, and type of crop but also of the biochar properties. De la Rosa et al. (2014) concluded that not all biochars should be applied as soil ameliorants. The inherent variability of biochars due to different feedstock and production conditions implies a high variability of their effect on soil properties and productivity. This strongly suggests that the production and use of biochars as soil improvers will need to be customized for each situation. Furthermore, due to the irreversibility of biochar application, it is necessary to perform detailed studies to achieve a high level of certainty that adding biochar to agricultural soils, for whatever reason, will be environmentally sustainable and will not negatively affect soil health and productivity.

The referred study has been published in the November issue of the Journal Science of the Total Environment, which has also caught the attention of the media interested in the widespread of science to the general public such as the internet newspaper ( and radio broadcast (

This research group is actively involved in the EU COST Action TD1107 ‘Biochar as option for sustainable resource management’ which comprises more than 200 researchers from 20 different countries of the EU.

Very recently, the group has carried out an experiment at the experimental station “La Hampa” with Helianthus annuus on the same biochar amended calcic Cambisols. The latter experiment will constitute Results of the latter experiment will constitute a valuable tool and innovative information for stake holders and farmers working with Mediterranean non-irrigated plantations.

De la Rosa, J.M., Paneque, M., Miller, A.Z. Knicker, H. 2014. Relating physical and chemical properties of four different biochars and their application rate to biomass production of Lolium perenne on a Calcic Cambisol during a pot experiment of 79 days. Science of the Total Environment 499, 175-184.


Figure from greenhouse experiment

la hampa-exp1      la hampa-exp2

Figures from the experimental field experiment at “La Hampa” Station

Acknowledgements: The Marie Skłodowska-Curie actions (REA grant agreement nº PCIG12-GA-2012-333784-Biocharisma project) and the Spanish Ministry of Economy and Competitiveness (MINECO) (project PCGL2012-37041) are thanked for the financial support of the present study. The “Fondo Social Europeo” is thanked for funding J.M de la Rosa JAE-Doc contract. The European Biochar Network (Biochar as option for sustainable resource management-COST action TD1107) and Bodegas Torres (Spain) are acknowledged for providing the biochar samples. Ignacio Giron is thanked for his support at the field experiment.

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