Silvipastoral systems: how to use them for carbon neutral milk production?

The potential of tree component neutralization was studied to understand the relationship between livestock, forest production and greenhouse gas (GHG) emissions. The objective of this work was to evaluate the carbon balance in a silvopastoral system including semi-intensive dairy farming and to quantify emissions per unit milk produced in Visconde do Rio Branco, Minas Gerais state, Brazil. The tree component of the silvopastoral system was a hybrid of Eucalyptus grandis x Eucalyptus urophylla in a semi-intensive production system, including Brachiaria decumbes as forage grass and crossbred dairy cow. Carbon stock was calculated from the estimated wood volume with forest inventory data, wood density and wood carbon content factor for tree species. Livestock (enteric fermentation and animal waste management), electricity, fuel consumption, nitrogen and limestone fertilization were the GHG emissions considered using emission factors. The carbon balance was obtained by comparing annually the GHG emissions with the increase of this element. The Average Annual Carbon Increment (IMAC) was 7.631 Mg CO2e ha(-1 )year(-1) and the Annual Average Emission of 5.817 Mg CO2e ha(-1 )year(-1). The carbon balance, in all the years, was positive evidencing the contribution of the silvopastoral system to minimize GHG emissions and neutralize the emissions in milk production.