Epamig project will measure carbon and water indices in integrated production systems

Soil care was the topic of discussion at the 26th United Nations Conference on Climate Change (COP-26), an event that brought together authorities from different countries between the 1st and 12th of November in the city of Glasgow, Scotland. Conserving soil has positive impacts on water quality, climate and food production. However, erosion rates are greater than natural soil renewal rates, even in more developed countries.

To take care of the soil, it is necessary to pay attention to the dynamics that exist between water and carbon. Under adequate humidity conditions and sufficient availability of macro and micronutrients, the higher the carbon content in the atmosphere, the greater the vegetable productivity and, consequently, the greater the carbon fixation. On the other hand, in soil conditions with water deficiency or low nutrient availability, carbon fixation by plants is compromised.

Focusing on the commitments made at COP-26, the Agricultural Research Company of Minas Gerais (EPAMIG) will start a project to quantify carbon inputs and outputs from the soil, during forage production, in a crop-livestock integration system ( ILP) and crop-livestock-forest (ILPF). Furthermore, the project will analyze the amount of water used for each kilogram of forage produced in these systems compared to other conventional systems.

According to IBGE data, in Brazil pastures constitute the basis of ruminant production and occupy around 150 million hectares. However, the degradation of these areas, in several Brazilian regions, has reduced forage productivity, which compromises environmental sustainability and the profitability of livestock farmers.

“The fact is that the degradation of pasture areas directly affects forage production, nutrient cycling and geochemical carbon and water cycles. This scenario is a challenge for current agriculture. It is necessary to maintain high levels of productivity to obtain biomass production, photosynthesis, nutrient cycling and physical structuring of the soil. This is a virtuous cycle that enables the sustainability of agriculture”, says EPAMIG researcher and research coordinator, Fernando Franco.

The researcher also explains that in recent years integrated production systems have been part of the Brazilian agricultural scenario. Systems that integrate livestock with agricultural activity, in rotation, consortium or succession, in the same area and in the same year, are classified as crop-livestock integration system (ILP). Systems that associate ILP characteristics with forestry activity, in the same area and at the same time, are classified as crop-livestock-forest integration systems (ILPF).

“Recovering degraded pastures is work that cannot wait. From this perspective, integrated production systems have been considered sustainable and profitable alternatives. Agricultural harvests amortize the costs of recovering pastures; Forests provide animal comfort and fix carbon in the wood that has been used preferably in the furniture industry. EPAMIG remains firm in its purpose of generating the best solutions for producers and the environment”, he points out.

The research steps

EPAMIG's research will be conducted at the Getúlio Vargas Experimental Field, located in the municipality of Uberaba (MG). The experiments will begin in the 2021-2022 agricultural harvest and will last two years, scheduled to end in August 2023.

Fernando Franco says that seedlings of Corymbia citriodora, a species of eucalyptus known for producing excellent quality wood and furniture potential, will be planted. In addition, corn seeds will be planted between the rows of trees in a consortium with brachiaria Urochloa brizantha, from the Marandu cultivar.

As a parameter, the studies will be carried out next to a degraded pasture and a native forest, both present in the EPAMIG Experimental Field in Uberaba.

In total, the forage will be produced in five different systems: degraded pasture, monoculture pasture, monoculture cropland, ILP and ILPF.

“Carbon inputs will be evaluated through the estimate of carbon present in the dry matter of each plant species accumulated monthly. Outputs will be evaluated by estimating carbon emitted from the soil through CO₂. Water inputs into the system will be evaluated through precipitation quantification. The outputs will be evaluated by quantifying crop evapotranspiration and monitoring the moisture present in the soil”, concludes Fernando Franco.

Carbon in the soil

Carbon forms the basis of life on Earth. Through photosynthesis, energy from sunlight is captured and forms bonds between carbon atoms, a reaction that forms organic molecules. A part of these molecules is used as an energy source by the plants themselves and returns to the atmosphere in the form of carbon dioxide (CO₂). The other part is fixed in plant biomass, especially in wood and soil, through the processes of decomposition of deposited organic material and humification of organic matter.

The accumulation of carbon in the soil is favored by crop development and management and conservation practices. In this sense, the arboreal component present in the ILPF system can provide environmental benefits in terms of soil and water conservation and carbon sequestration.

“Specialized literature shows that a fast-growing tree in a tropical climate has the potential to fix a carbon rate that is equal to the rate of CO₂ emitted by up to 13 animals over the course of a year”, highlights Fernando Franco.

The research project is funded by the Minas Gerais State Research Support Foundation (Fapemig). EPAMIG is a company linked to the Secretariat of Agriculture, Livestock and Supply of Minas Gerais (Seapa).