The agroforestry system doubled the carbon stored in the soil compared to conventional farming.Carbon accumulation reached 2.24 tons per hectare per year over six years.Carbon in the soil increased from about 14 to more than 27 tons per hectare.Beans grown among the trees maintained productivity above 1,000 kg per hectare.The experiment has inspired the adoption of similar systems on rural properties in the Cerrado region.

An experiment conducted by Embrapa Rice and Beans (GO) over six years in Santo Antônio de Goiás (GO) showed that the Agroforestry System doubled the carbon stored in the soil compared to conventional soybean and corn cultivation, accumulating 2.24 tons per hectare per year. During the same period, the common bean grown between the rows of trees produced more than 1,000 kilograms per hectare.

In the evaluated area, soil organic carbon increased from approximately 14 to over 27 tons per hectare in the 0-20 centimeter layer after replacing the annual corn and soybean rotation system with agroforestry systems (AFS). This result is associated with increased biomass production and a continuous supply of organic matter to the soil, provided by the tree species and the use of green manures in the system.

The experiment, developed at Fazenda Capivara, headquarters of the Unit, in an area of ​​1 hectare, was conducted as follows: after planting seedlings of native Cerrado trees in rows, such as aroeira, cagaita and baru; green manures, such as crotalaria ( photo on the right ), were sown at the beginning of the rainy season, between the rows of forest species, after soil preparation.

Next, the crotalaria was mechanically cut and the beans were cultivated using no-till farming. During the off-season, a new planting of crotalaria was carried out, with new soil preparation. This management was repeated for six years, until the growth of the trees prevented agricultural cultivation between the rows.

From the beginning of the production arrangement, agroecological principles were adopted. During cultivation, weed control was done manually, and organic fertilizers, organomineral fertilizers, and biofertilizers were used to replenish nutrients in the soil.

Researcher Agostinho Didonet, the system’s creator, highlights the results of the long-term experiment: “The production of common beans in an agroforestry system is perfectly viable, contributing to food security. Although crotalaria does not directly affect grain productivity, the yield of around 1 ton per hectare represents a good result for the summer crop in agroecological systems in the Cerrado, which depend only on rainwater.”

Production combined with sustainability.Researcher  Agostinho Didonet  adds that green manures, such as crotalaria, contribute to the production of organic matter and to the increase of carbon in the soil over time, especially in the spaces between tree rows. “The rate of organic carbon accumulation in the soil profile, between 0 and 20 centimeters deep, was approximately 2.24 tons per hectare per year, over six years,” he emphasizes.Similarly, the researcher highlights the role of trees in the system. In the planting line of native Cerrado species, the rate of organic carbon accumulation in the soil reached 2.43 tons per hectare per year. In this component, the increase in organic matter is associated with plant residues deposited in the soil, mainly leaves and branches.The formation of this layer of plant debris — known as leaf litter — and its decomposition are responsible for transferring nutrients to the soil, allowing for its recycling and return to the system.