An age-old agricultural method is helping to combat soil degradation and protect a source of food and income for more than 75% of the population in Madagascar. Through a study using isotopic techniques on the mountainous island, scientists working with the IAEA, in cooperation with the Food and Agriculture Organization of the United Nations (FAO), found that traditional terrace farming can reduce soil erosion and run-off in the country by up to 40% when compared to unprotected agricultural fields.
“Farming on Madagascar is a challenge because there are a lot of steep, mountainous areas and high plateaus that limit the options on how to grow food,” said Lionel Mabit, a soil scientist at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. “Then when you add soil degradation and the impact of climate change, picking the right approaches to farming is essential. This project is helping them to implement optimal soil conservation strategies.”
Farmers rely on soil as an essential environment for growing food. Madagascar’s upland areas are particularly vulnerable to soil degradation due to challenging physical conditions, such as steep slopes and uneven ground that make soil more prone to eroding and running off. This is exacerbated by the effects of climate change like drought, floods and unpredictable rainfall that further break down soil structure and compromise its health. According to the FAO, around 30% of Madagascar’s land area is degraded.
The traditional method of farming in upland Madagascar is terrace farming. A terraced field is a series of raised flat areas, or steps, cut into the side of a sloping hill where farmers can grow their crops. These steps are formed out of soil and are often reinforced with stones or trees. Little channels are typically built into the steps to allow water to flow freely down the slope while holding the soil in place.
