ROME, Feb. 14 (Xinhua) -- Improving management practices in grasslands used especially for animal grazing can enhance the capacity of soils as carbon sinks, and help countries reach their climate goals, the United Nations Food and Agriculture Organization (FAO) said in a report published on Tuesday.
Soils are the second largest carbon pool on Earth after oceans, and they contribute to the realization of the United Nations (UN) Sustainable Development Goals (SDGs) through carbon sequestration, the Rome-based agency said.
Grasslands contain approximately 20 percent of the world's soil organic carbon (SOC) stocks, and thus they can play a significant role in the global carbon and water cycles, the FAO's first Global Assessment of Soil Carbon in Grasslands study said. Many grasslands have suffered losses of SOC due to human activities, such as intensive livestock grazing and agricultural uses, it noted.
The study assessed the baseline SOC stocks of grasslands in 2010 and estimated their potential to sequester carbon in the soil.
It said that there was an estimated annual uptake of 63.5 megatonne of carbon in 2010 in grassland soils to a depth of 30 centimeters globally, and found that "if the SOC content in the 0-30-centimeter depth layer of available grasslands increased by 0.3 percent after 20 years of the application of management practices that enhance SOC sequestration, 0.3 tonnes of carbon per hectare per year could be sequestered."
The report showed that most of the grasslands in the world have a "positive carbon balance," but negative carbon balance was found in East Asia, Central and South America, and in Africa south of the Equator, "meaning these stocks are likely to be decreasing due to anthropogenic stresses combined with climatic conditions."
The report included main recommendations for grassland systems, including "to prioritize carbon returns in deteriorated soils that have a negative carbon balance, and to protect SOC in areas ... with high carbon stocks." ■
