Soil carbon sequestration in semi-arid regions as a strategy for sustainable agriculture

The semi-arid region exhibits high environmental vulnerability, which is further exacerbated by the widespread use of conventional management practices, such as, vegetation cutting and burning, monocultures and overgrazing. These practices significantly accelerate declines in primary productivity and increase the risk of soil degradation. In recent years, climate change has contributed to the expansion of degraded and desertified areas within the semi-arid zone, leading to reductions in biodiversity and soil organic carbon (SOC) stocks. These changes negatively impact the chemical, physical, and biological properties of the soil. Consequently, promoting soil carbon sequestration in dry areas has become a complex challenge. This difficulty is compounded not only by the prevalent reliance on traditional management systems but also by the natural conditions of the Caatinga biome, which favor organic matter oxidation due to high temperatures and limited organic input. These factors contribute to soil health deterioration, food insecurity and adverse effects on smallholder livelihoods.

In response, conservation technologies, focused on maintaining soil cover, minimizing disturbance, and integrating crop systems, have begun to be adopted by some smallholders in the Brazilian semi-arid region. These practices aim to protect and restore natural or modified ecosystems in a balanced manner, generating benefits for biodiversity and human well-being. Examples include reforestation with native and adapted species and agroecological systems, both of which offer multiple advantages: generating income, protecting soil, and supporting sustainable production. Reforested areas have proven essential for maintaining agricultural productivity during dry seasons, serving as sources of animal feed and increasing biomass and soil carbon storage, thereby helping to mitigate greenhouse gas emissions. Similarly, agroecological systems, based on plant diversity, enhance nutrient cycling and promote the reconstruction of soil organic matter. These practices ensure access to healthy food for families, conserve biodiversity and help address the socio-environmental challenges faced by the region. Research indicates that these conservation technologies can effectively increase soil carbon sequestration and improve soil health indicators. Such benefits positively impact the food and nutritional security of farming families, representing a vital strategy for soil conservation, climate change mitigation, and providing a sustainable source of income and dignity for local communities.

Language of the presentation: Portuguese