World Environment Day 2020: How the IAEA Contributes to Soil, Plant and Animal Biodiversity

Soil is the thin layer on earth that hosts a quarter of our planet’s biodiversity. It is the most diverse habitat of micro- and macro-organisms, such as bacteria, fungi, nematodes, vertebrates, invertebrates, which interact and contribute to the global cycles that make all life possible. These natural interactions impact positively – and for free – food safety and security, animal and human health, water purification, as well as climate change mitigation and adaptation.  They underpin the health of natural ecosystems and their capacity to provide us with the basics to live.

“Unfortunately, we’re degrading and destroying our soils faster than they develop or replenish, through climate change, intensive agriculture, deforestation and industrial activity,” said Lee Heng, Head of the Soil and Water Management and Crop Nutrition Section at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.

For countries to develop strategies to better combat soil erosion and protect the microbial community of the soil, scientific data is required. For that purpose, the FAO/IAEA laboratory working on soil management is investigating how the diversity and structure of bacterial and fungal communities in soil can be linked to soil quality and soil erosion. This is determined using isotopes of carbon, nitrogen and plutonium (¹³C, ¹⁵N and ^239+240Pu).

Micro- and macro-organisms in the soil regulate greenhouse gas emission by enhancing carbon sequestration, and hence act against global warming. To support their action and help countries developing climate-smart agricultural practices for carbon sequestration, the IAEA and the FAO have recently launched a five-year coordinated research project on the use of carbon and nitrogen isotopes to quantify greenhouse gas emission, involving researchers from Argentina, Bangladesh, Brazil, China, Costa Rica, Ethiopia, Germany, India, New Zealand, Pakistan, Spain and Viet Nam.

Bacteria also have a key role to play in plant growth. In Benin for example, more than 5000 farmers have been trained to inoculate their legume crops with bacteria to facilitate the crops’ ability to capture nitrogen (plant fertilizer) from the atmosphere. The nitrogen-15 (¹⁵N) isotopic technique was used to identify legume varieties with high nitrogen fixing capability and to quantify the amount of nitrogen captured by these legumes. As a result, farmers benefitted from an increased yield for both grain legumes and cereal crops – while saving on the amount of fertilizer applied.

Globally, local varieties and breeds of domesticated plants and animals are disappearing despite local efforts, according to the 2020 IPBES report. “This loss of diversity, including genetic diversity, poses a serious risk to global food security by undermining the resilience of many agricultural systems to threats such as pests, pathogens and climate change,” the report states.  

Created 25 years ago, the FAO/IAEA Plant Breeding and Genetics Laboratory has worked with thousands of scientists worldwide to develop improved plant varieties of both major crops and underutilized and indigenous crops. Examples include higher-yielding sorghum and cowpea, banana resistant to major fungal disease, drought-tolerant peanut varieties and many more. They were developed using irradiation of seeds, creating new lines be selected for their superior properties.

“Our work in plant mutation breeding helps countries improve existing crop varieties by bringing in new genetic diversity to provide better and stable yields under existing and evolving environmental challenges, including climate change,” said Shoba Sivasankar, Head of the Plant Breeding and Genetics Section. “In that sense, we are bringing in new ‘genetic’ diversity, which does not crowd out local biodiversity, as it focuses on agricultural lands where a previously existing crop variety is improved upon.”

The IAEA also supports countries in the field of animal reproduction and breeding by developing protocols and guidelines that help characterize the biodiversity of livestock and use it more sustainably. It provides services to animal genetics laboratories and livestock professionals, including training on the application of nuclear and nuclear-related genotypic techniques to identify environmentally adapted breeds with superior genetic makeup to tolerate climatic changes such as draught tolerance or to mitigate susceptibility to emerging or re-emerging animal diseases in order to improve the livelihood of farmers.

“The impacts of invasive species are second only to natural habitat destruction as a cause of global biodiversity loss. They can interfere with ecosystem services or disrupt whole ecosystems and cause the decline of many of the native species that are now listed as endangered or threatened,” said Walther Enkerlin, Entomologist at the Joint FAO/IAEA Division.

The IAEA and the FAO help countries become free of invasive species, such as the Mediterranean fruit fly in the Dominican Republic, using a nuclear technique known as the sterile insect technique (SIT). Sterile insects when released in the field mate with wild insects of the same species, so no offspring is produced, resulting in the reduction of a pest population over time. This technique reduces pesticide use and preserves biological diversity, as a recent eight-year study led in Senegal on tsetse flies showed. Hence, controlling invasive pest species supports not only agriculture but also biodiversity.  

“The use of nuclear techniques is very diverse – and most people would not associate it with preserving biodiversity,” said Enkerlin. “But it is, and it works all around the world.”