(Sicilian farmers look) Back to the future

Wheatfield with Crows, by Van Gogh. Van Gogh Museum, Amsterdam.
Wheatfield with Crows, by Van Gogh. Van Gogh Museum, Amsterdam.

Sicilian farmers are returning to cultivate ancient seed. This is to recover the ancient wisdom that feed the island and Italy since ancient times. Giuseppe Li Rosi is a local farmer and one of the strongest supporters of the return to traditional agriculture. He has converted a property of 100 hectares to traditional farming and proudly guards three local seed varieties (“Timilia”, “Maiorca” and “Strazzavisazz”), keeping at least 10 hectares for each one. Continue reading

The long, long travel from rock to soil (I)

There is hardly a subject in all nature, of which the majority of people has so unclear terms and which has hitherto been so completely misunderstood, as the soil on which they walk.

F.A. Fallou

Soil is often considered as the skin of the Earth and is located at the interface between the lithosphere, hydrosphere, atmosphere and biosphere. Air, water, rock and living beings interact to form soil, which, in turn, is the physical and nutritional support for living organisms in emerged areas. Currently, we define soil is an open system that temporarily stores the necessary resources for living organisms. The availability of these resources (water, energy, mineral nutrients, etc.) depends on the intensity and speed of exchange processes between soil and the rest of compartments of ecological systems.

Soil in the interface, by Antonio Jordán. Distributed by Imaggeo.

But the concept of soil has been modified in accordance to the increasing understanding of its components and the relations among them. During centuries, soil was considered not more than dirt on rocks, when not simply one of the strata in geological profiles. See, for example, the following statement: “That all the earthy part of soil consists of minute fragments of rock does not require argument, or need proof, but inspection merely to determine it. We have only to place specimens under the magnifier and their rocky origin will become manifest” (Eaton and Beck, 1820). Continue reading

Soil facts

As part of the activities of the International Year of Soils, FAO has published the following Soil Facts. Contribute with your comments!


The current rate of soil degradation threatens the capacity to meet needs of future generations.


We need healthy soils to achieve our food security and nutrition goals.
Did you know that a tablespoon of soil has more micro-organisms than the whole human population on Earth?


Multiple roles of soils often go unnoticed.


Our soils are precious. Did you know it can take up to 1,000 years to form 1 cm of top soil?


Soils are key in the global carbon cycle. They help us to mitigate and adapt to the climate change.

Fire and soil microorganisms: where should we focus on?

Gema Bárcenas-Moreno
University of Seville, Sevilla, Spain

Currently, the complexity of soil microbial ecology on soil systems is a hot topic in the environmental sciences, since the scientific community has achieved a deep knowledge of the relevance of microorganisms in soil processes. After several decades of study of the effects of wildfires on soils, one of the main conclusions is that soil microbial populations are very sensitive to fire, which allows us to use them as a tool to assess the impact of fire on ecosystems.

Polysaccharides distribution due to microbial colonization in a soil microaggregate. Credit: Imaggeo/Maria Hernandez-Soriano. Click the image for more information.
Polysaccharides distribution due to microbial colonization in a soil microaggregate. Credit: Imaggeo/María Hernández-Soriano. Click the image for more information.

Continue reading

A dark future sprouting from sealed soil

A view of Quito (Ecuador). Credit: Martin Mergili. Click on the image to see the original picture and details in Imaggeo.

Every year in Europe, soils covering an area larger than the city of Berlin are lost to urban sprawl and transport infrastructure. This unsustainable trend threatens the availability of fertile soils and groundwater reservoirs for future generations. A new report made public today by the European Commission recommends a three-tiered approach focused on limiting the progression of soil sealing, mitigating its effects and compensating valuable soil losses by action in other areas.

Environment: Soil sealing in the EU threatens the availability of ecosystem services. European Commission – IP/11/624   23/05/2011

You live on sealed soil

Look out your window. If you do not live isolated in the countryside, it will be difficult that most of which you can see is not sealed floor. Most land around you is covered by buildings or pavement. It is normal, you live in a town or a village. There is much more space out there! Is there much space out there?

Decay. Credit: Marcel Van Oijen. Click on the image to see the original picture and details in Imaggeo.

Soil sealing occurs when it is covered with impervious surfaces such as asphalt or concrete. These materials are necessary for construction of buildings and road materials, but its use implies the disappearance of agricultural resources and food production, significant changes in the hydrological processes at catchment scales as well as the loss the most important soil functions as habitat and biological support, biomass production, gene pool, sink of greenhouse gases, filtration and transformation of substances and protection of groundwater and the food chain …

Organic farming. Credit: Kristof Van Oost. Click on the image to see the original picture and details in Imaggeo.
Soil products. Credit: Artemi Cerdà. Click on the image to see the original picture and details in Imaggeo.

Even in cities, unsealed floor areas are necessary. because rain water can not flow through paved surfaces, and the ability of the sewerage system is overloaded.

A problem linked to social inequality

The rapid occupation of land for buildings has become one of the most important environmental problems. Due to migration from rural areas to the big cities and the intense changes of use from the second half of the twentieth century until now, the area of ​​land devoted to agriculture or natural vegetation is declining. And the reasons are obvious: the private economic benefit obtained from construction is much higher than from farming. Besides food products can be imported from other countries. But … is this a sustainable policy? How long?

Just one example: in Andalusia, where I live, land consumption per capita has increased by 4 in the last 50 years, from 87 m2 in 1956 to more than 337 m2 in 2007. Although causes vary from one region to another (industrial and commercial growth, infrastructure construction, mining activities, landfills, etc.), in all cases urban expansion is the main cause of soil sealing.

Rural roads change the landscape. Credit: Artemi Cerdà. Click on the image to see the original picture and details in Imaggeo.

And it’s not just a problem in the south of Europe. In small countries like Austria, only one third of the land can be used for construction. But urban and industrial expansion continues (the Viennese population grows at a rate of 20,000 people per year), so that in many parts of the country there is not much space and urban planning should be seriously analyzed.

Land abandonment is a key factor of Mediterranean Landscapes. Credit: Artemi Cerdà. Click on the image to see the original picture and details in Imaggeo.

In the EU, At least 275 ha of soil per day were lost, amounting to 1,000 km² per year Between 1990 and 2000, although this trend has been reduced to 252 ha per day in recent years, but the rate of land consumption is still worrying. Between 2000 and 2006, the EU average increase in artificial areas was 3%, with increases attaining 14% in Ireland and Cyprus and 15% in Spain (read more here).

May we get rid of soil sealing?

Obviously, people need to be fed. And for that we need transport infrastructures and consequent soil sealing. We also need infrastructures for the processing of raw materials. As a colleague says, “processes generate structures“. Therefore, we can not do without soil sealing. But we can achieve a balance.

How to? Discovering the causes

The poor generally have access only to areas that have higher risk for health and income generation. And they generally lack the resources to reduce the exposure to the risk or to invest in alleviating the causes of such risk. Environmental degradation therefore can affect the health and nutrition status of the poor and lower their productivity. This can happen both directly through, for example, lower yields per unit of labor or land because of reduced soil quality, and indirectly through the reduced physical capacity of labor to produce because of malnutrition and poor health. Even in cases where the poor are healthy labor productivity can be low due to increased time being allocated to less-productive activities such as fuel wood collection and away from agriculture and other income generating activities.

Consultative Group on International Agricultural Research. CGIAR research priorities for marginal lands. Document No.:SDR/TAC:IAR/99/12.

Zooming in community. Credit: Veilo Coviello. Click on the image to see the original picture and details in Imaggeo.

In current systems, urban population, for which most of these infrastructures are intended, is mostly concentrated in points far from the sources of production. The rural population migrates to cities due to low access to education, health care and, above all, low incomes and job expectations.

Ploughing in Central rift valley, Ethiopia. Credit: Saskia Keesstra. Click on the image to see the original picture and details in Imaggeo.

Although the consequences of this migration are not as severe (they are) in the so-called First World, the urban agglomeration does not solve these problems. More, it contributes to create large pockets of poverty in the periphery of cities. Here we have an interesting political issue. Are we heading towards a future of smart cities for the ruling class surrounded by belts of hunger, poverty and insecurity?

Getting crowded. Credit: Albin Hammerle. Click on the image to see the original picture and details in Imaggeo.

Read more


This post has been also published in the EGU Blog Network.

Mediterranean Environmental Research Group (GRAM)

The Mediterranean Environmental Research Group, (GRAM) from the University of Barcelona has over 20 years of working experience in the field of the effects of forest fires on soil properties. In 1998 the doctoral thesis entitled “Fire effects on soil properties, the role of fire intensity” carried out by Xavier Úbeda emphasized the importance of fire intensity impacts on soil physico-chemical properties and the consequent implications, as the increase of runoff and erosion in post-fire environments. From this thesis some papers were published in national and international journals. This work was funded by two European research projects related to forest fires, as the “Post fire soil and vegetation dynamics in natural and afforested areas in Southern Europe: The role of fire intensity.” The most important results were the reaffirmation of the importance of fire intensity impacts on soil properties, the increase of erosion and the implications on vegetation recuperation.

Plot located in a urban-forest interface area (see www.ub.edu/gram).
Plot located in a urban-forest interface area (see http://www.ub.edu/gram).

In the last twelve years, the GRAM members worked intensively in the study of prescribed fire impacts on soils.  Samples were collected before, immediately after and one year after the prescribed fire experiments in order to observe the impact of this type of landscape management on soil properties, mainly in nutrients behavior. This research was possible through collaboration with the GRAF (Grup de Recolzament to Actuacions and Forestry) from the Generalitat de Catalunya, which carries more than twelve years conducting controlled burns for forest management. Two projects from Spanish Ministry have funded this research: “Alterations of environmental quality in fire-affected soils in Mediterranean environments. The study of hydrophobicity, and development of new techniques to evaluate, and mitigate degradation“and the project: “Assessment of the quality of Mediterranean soils affected by the heat to medium and long term, applying an index of environmental quality“. From these projects, two theses were directed by the person who signs this petition (Dr. Xavier Ubeda). Both were defended in 2010. Luís Outeiro: “Geostatistics and environmental management; studies and applications of the spatial and temporal variability in soil and water “and Paulo Pereira:” Effects of fire temperatures on the chemical and physical characteristics of the Mediterranean species ash and their effect on water quality”. From the thesis of Luis the most relevant results were that based on geostatistical analysis, that low-intensity prescribed fires do not cause important variations on soil properties, but the repetition of this technique can be harmful, if carried out in a short time period. From the thesis of Paulo it was observed that fire temperatures and severity have an important effect on the ash physico-chemical properties, which will influence temporarily the type and amount of nutrients in the soil and available to landscape recuperation.

Studies on soil erosion (see www.ub.edu/gram).
Studies on soil erosion (see http://www.ub.edu/gram).


In the project funded by the Ministry of Environment of the Government of France with the title “Dynamique des paysages, érosion développement durable et dans les montagnes méditerranéennes” some interviews were carried out with stakeholders engaged in forest management. The stakeholder’s interviewed were staff from councils and consortia, councils, Forest Ownership Center and Forest Technology Centre of Catalonia. Using these interviews, Roser Rodriguez is currently doing a doctoral thesis entitled “Socioecology wildfire: an approach to environmental sociology wildfires central Catalonia.”

The GRAM has organized several national and international conferences, as the ‘ International Meeting of Fire Effects on Soil Properties “held in 2007 in Barcelona (http://www.fire.uni-freiburg.de/course/meeting/2007/meet2007_04.htm) and in 2013 in Vilnius (https://sites.google.com/site/fespivvilnius/). Other international congresses were organized by the group in several European Geoscience Assemblies.

The Members of the group have participated as “guest editor” in three special issues: “Fire Effects on Soil Properties” Catena. 2008 Vol 74 Issue 3, “Fire Effects on Soil Properties: Forest Fires and Prescribed Fires”. Environmental Research. 2011 Vol. 111. Issue 2 and “Incendis and Forestry” 2012. Treballs of the Catalan Society of Geography. Other three Special issues are ongoing, “The role of ash in fire-affected ecosystems: A physical, chemical and biological approach (Catena)”, “Soil processes in cold-climate environments (Solid Earth)” and “Soil mapping, classification, and modelling: history and future directions (Geoderma)”.

More information on the website of GRAM Group (www.ub.edu/gram).


This post has been published also in the EGU Blog Network.

Will drinking tea get us thinking about soils? Yes, but only if you help us spread the word!

Taru Lehtinen
PhD candidate at the Faculty of Life and Environmental Sciences, University of Iceland

Meet Taru at EGU2014 in sessions SSS10.3 and SSS10.8.

The Tea Bag Index Project wants to create a global map on decomposition with the help of citizen scientists. We use teabags to collect vital information on the global carbon cycle. With our protocol (see our web page and our article: Keuskamp et al., 2013), citizen scientists worldwide can collect data without much effort or instrumentation.

Tea Bag Index Project developed a simple and cheap method, which anyone can use to measure decomposition in the soil, simply by burying teabags. Tea Bag Index Project want to gather data points from all over the globe through the involvement of citizen scientists.

Two main questions to be answered with the data gathered:

  1. How do environmental conditions determine the speed of decomposition?
  2. How do environmental conditions determine how much is broken down?

Eventually, a global soil map of decomposition will be created that can be used for educational purposes and to make current climate models even more accurate.

What is about?

Decomposition (the decay of organic material) is a critical process for life on earth. Through decomposition, nutrients become available for plants and soil organisms to use as a food source in their metabolism and growth. When plant material decomposes, it loses weight and releases the greenhouse gas carbon dioxide (CO2) into the atmosphere. In cold environments, breakdown is slower than in warm environments, meaning more carbon is stored in the soil and less CO2 is released. Factors like moisture content, acidity, or nutrient content of soils can also influence how quickly plant material decomposes


For better insight into global CO2 emissions from soils it is important to know more about decomposition in those different soils. Such an insight is important to improve climate models that show CO2 fluxes. To clarify the picture of global decomposition, we need a lot of information on different soil characteristics and related decomposition rates around the world. Large efforts have been taken to create a soil map of the world; however, predictions on the relations between soil an decomposition are often imprecise. It would be a great improvement if we could actually measure decomposition (rate and degree) globally.

Tea Bag Index Project developed a simple and cheap method to measure decomposition rate and degree. By burying everyday tea bags.

As tea is plant material, the weight loss of nylon teabags over time represents the decomposition of the plant material within an ecosystem. After three months buried in the soil of interest, the bags are dug up, dried and weighed. By burying two types of tea with different decomposition rates, we obtain information on how much and how fast plant material is broken down.

The importance of this research

Efforts have already been taken to map global soil and climate conditions; however an index for decomposition rate is still missing. Predictions of decomposition used in climate models are often imprecise.

The idea is to use the Tea Bag Index to collect data from around the world to feed databases in the global soil map, and to get as many citizen scientists as possible involved. This crowdsourcing approach will strengthen the dataset; due to the power-by-numbers principle; and it will increase awareness of soil science at the same time.

Soil receives very little attention in media coverage of environmental issues. Tea Bag Index Project specifically aims to involve school classes and youth groups as those have shown the highest response and most reliable data so far.

We hope to get as many school classes and youth groups as possible to get involved in the project! Tea Bag Index Project would be grateful for your help in spreading the word about this new method, and your support in making a global decomposition map reality!

If you want to discuss during EGU2014 send an email to Taru Lehtinen, and feel free to send comments to tbi@decolab.org! If you want to join our mailing list and hear more from us, look for the following link: http://www.decolab.org/tbi/mailinglist.php.

Additional information

Our web page: http://www.decolab.org/tbi/

Our mailing list: http://www.decolab.org/tbi/mailinglist.php

Know more

Keuskamp JA, Dingemans BJJ, Lehtinen T, Sarneel JM, Hefting MM. 2013. Tea Bag Index: a novel approach to collect uniform decomposition data across ecosystems. Methods in Ecology and Evolution 4, 1070-1075. DOI: 10.1111/2041-210X.12097.

Lehtinen T, Gísladóttir G, van Leeuwen JP, Bloem J, Steffens M, Ragnarsdóttir KV. 2014. Do aggregate stability and soil organic matter content increase following organic inputs? Geophysical Research Abstracts 16, EGU2014-905-1.

Lehtinen T, Schlatter N, Baumgarten A, Bechini L, Krüger J, Grignani C, Zavattaro L, Costamagna C, Spiegel H. 2014. Effect of crop residue incorporation on soil organic carbon (SOC) and greenhouse gas (GHG) emissions in European agricultural soils. Geophysical Research Abstracts 16, EGU2014-10278.


This post has been simultaneously published in the EGU Blog Network.