Soil Biodiversity Key to Environmentally Friendly Agriculture

Below Ground Biodiversity—from Worms to Bacteria—Key to Environmentally Friendly Agriculture

Curitiba/Nairobi, 22 March 2006 - Improved crop yields are being enjoyed by some developing world farmers who have turned to soil living bacteria and fungi rather than artificial fertilizers to boost harvests.

The improvements are some of the first fruits of a project involving Brazil, Cote d’Ivoire, Indonesia, India, Kenya, Mexico and Uganda implemented by the United Nations Environment Programme (UNEP) with co-financial support of Global Environmental Facility (GEF)

It is aimed at understanding and harnessing ‘below ground biodiversity’ for sustaining, restoring and improving the fertility of the land.

The project, co-ordinated by the Tropical Soil Biology and Fertility Institute (TSBF-CIAT), is also aimed at cataloguing the variety of below ground life forms from worms and beetles to fungi and bacteria.

Experts believe this represents the biggest source of untapped and unknown life on Earth and thus a potential source of new drugs up to pharmaceutical and industrial products.

The improvements are highlighted by farmers operating in and around the Los Tuxtlas Biosphere Reserve in northern Mexico.

They have been testing several kinds of soil dwelling microbes that fix nitrogen from the air and make it available to the plant.

For example one, known as Rhizobium etli and found naturally in the local forest soils, was tested on beans as a ‘bio-fertilizer’.

Bean yields have increased by up to over 40 per cent. Production costs, mainly linked with reduced use of artificial fertilizers, have fallen by half.

A survey of over 330 bean producers indicates that the economic value of this below ground biodiversity and its fixing of nitrogen is the key to profitability.

Experts claim the impact goes beyond the direct economic benefits to agriculture. The Los Tuxtlas reserve is a biologically important rain forest under threat from deforestation. Indeed 40,000 hectares have been lost in the past 40 years.

Boosting yields using naturally occurring soil organisms may reduce the need to clear more forest for agriculture thus helping to conserve the forest and its biodiversity both above and below ground.

Three years into the project, the Mexican researchers are also unearthing new species including three new species of ants and up to 15 new species of mycorrhizal fungi —organisms that help the roots of plants extract minerals and water from the soil.

The Mexican team, led by Isabelle Barois of the Institute of Ecology in Xalapa, Veracruz, are also about to start tests using fungi to boost the bulb size of lilies.

Lilly flowers are a big money spinner for the people of Venustiano Carranza but the size of the bulbs has been shrinking with experts linking this to a pest. It is hoped the soil fungi, injected into the roots, can counter the decline.

Klaus Toepfer, UNEP’s Executive Director, said:” When people think of where new species might be found, they tend to think of the rainforests, mangroves or locations like mountain tops—not millimetres beneath their toes”.

“Harvesting the secrets of this understudied realm promises huge benefits in terms of delivering sustainable development and overcoming poverty by helping to restore the fertility of damaged and degraded lands and by naturally reducing the need for chemicals from fertilizers up to pesticides,” he added.

Jeroen Huising, the project’s coordinator at TSBF, said similar findings to those in Mexico were emerging in Africa. Here some types of Soya bean plants are able to form beneficial associations with nitrogen fixing bacteria, found naturally in the African soils.

“Preliminary calculations indicate that the benefits in terms of inorganic fertilizer saved, in other words what would have been required to get the same yield, amounts to around $180 million a year with Nigeria and South Africa seeing some of the biggest benefits,” he added.

“These preliminary findings underline not only the economic and environmental importance of below ground diversity but also the need to conserve it. Among the key findings emerging from all countries involved in this project is that intensive agriculture can significantly reduce soil life forms and therefore its fertility and productivity,” said Mr Huising.

Details of the $26 million project will be unveiled at the 8th Conference of the Parties to the Convention on Biological Diversity taking place in Curitiba, Brazil.

Other Highlights from the Project


The Brazilian team, coordinated by the Federal University of Lavras, have been focusing efforts on the Upper Solimoes river basin, the homeland of the remaining indigenous Amazonian people. It is also a noted hot spot for Amazonian “agrobiodiversity”.

The researchers have been screening the soils for a wide variety of organisms from termites, beetles and ants to fungi and bacteria. Over 15,000 specimens, many of which are believed to be new to science, have been added to national collections for further studies.

The research, which has also involved the 70 students in “taxonomic training and national capacity building”, is clearly demonstrating how land management affects the diversity of soil organisms and thus soil fertility.

“Below ground biodiversity was usually highest in forest or fallow—the traditional indigenous soil management—and lowest in pasture,” say the team, operating under the banner of BiosBrasil.


Researchers, coordinated by the University of Lampung, have been studying soils at two sites in Lampung and Jambi, Sumatra. Their results also confirm the impact of intensive agriculture on below ground biodiversity.

“The richness and abundance of ants, beetles and termites decreased with increasing land intensification…..intensification tended to reduce the individual earthworm size,” they say.

Indian scientists, coordinated by the Jawaharlal Nehru University, report on experiments with ‘rhizobium inoculation techniques” in which beneficial organisms are added to the rooting zone in soils. In some cases they have seen yields rise by nearly 70 per cent.

Other tests include the re-introduction of termites to damaged lands. “One paper show considerable success obtained with the use of termites for restoring degraded lands…increasing soil nitrogen and carbon,” say the scientists whose findings are published in a new book, Soil Biodiversity, Ecological Processes and Landscape Management (Oxford and IBH Publishing).


The Kenyan team, led by Professor Richard Mibey and carried out by the University of Nairobi, have found that beneficial organisms known as nematodes are more abundant in forest soils than in ones under cultivation.

Mycorrhizal fungi were more extensive in soils under agroforestry than in maize fields in the Taita hills.


The Ugandan researchers, coordinated by Makerere University, have clearly demonstrated a link between heavy chemical use and loss of species including termites and mycorrhizal fungi.

Soils in the Mabira Forest Reserve, located in the central-east of the country near Jinja, were also compared with nearby ones used for agriculture including tea and sugar cane plantations. Up to ten times more earthworms were found in the forest reserve soils than in the more intensively farmed soils.

In addition, they have found that intensive agriculture appears to boost the abundance of soil living pests like parasitic nematodes.

Notes to Editors

The 8th Conference of the Parties to the Convention on Biological Diversity, Curitiba, Brazil, 20 to 31 March

For More Information Please Contact Nick Nuttall, UNEP Spokesperson, Office of the Executive Director, on Tel: +254 20 762 3084; Mobile: +254 733 632 755 or when traveling and in Curitiba 41 79 596 57 37, E-mail:

If there is no prompt response, please contact Elisabeth Waechter, UNEP Associate Information Officer, on Tel: +254 20 7623088, Mobile: +254 720 173968, E-mail:

Alternatively contact Peter Okoth, Project Information Manager, Conservation and Sustainable Management of Below Ground Biodiversity (CSM-BGBD) project, on Tel: +254-20-7224775; Mobile: + 254-722 768537, Fax: 254-20-7224774/3, Email:,, Website:

If there is no prompt response contact Jeroen Huising, Global Project Coordinator, Conservation and Sustainable Management of Below Ground Biodiversity (CSM-BGBD) project, on Tel: +254-20-7224772; Mobile: + 254-734 600779, Fax: 254-20-7224774/3, Email:,, Website:

UNEP News Release 2006/18


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