A pathway for decreasing the water footprint from grazing-based beef production systems in the Tropics

Abstract

CONTEXT

Water availability shapes agricultural land use patterns, which in turn impacts water supplies. Beef cattle production is one of the most water-intensive food production activities. Therefore, it is fundamental to identify pathways to reduce water consumption and to determine suitable producing-regions to mitigate the current pressures on water resources.

OBJECTIVE

Our objectives were to assess the water footprint of beef cattle in different land use systems and investigate the potential of alternative production strategies to reduce the environmental impacts associated with water resources use.

METHODS

The water footprint of beef produced in conventional pasture system (CON), agropastoral (ICL), and agro-silvopastoral (ICLF) systems was analysed from cradle-to-farm gate using a life cycle assessment approach, which included a complementary analysis of the environmental impacts of the rainfall water consumption in the Brazilian Cerrado.

RESULTS AND CONCLUSIONS

Increases in the efficiency of the systems (e.g., greater feed conversion efficiency, stocking rates, reduced slaughter age of animals, amongst others) resulted in a lower water footprint and water scarcity footprint in ICL (18,332 L and 1526 L/kg carcass weight), followed by ICLF (31,024 L and 1846 L/kg carcass weight) compared to CON (60,023 L and 2446 L/kg carcass weight). The impact of rainfall water consumption (i.e., green water scarcity) was lowest in ICL (182–328 L_{world equivalents}/kg carcass weight). Although the tree presence in ICLF systems can limit the productivity, it improves the thermal environment as well as the canopy structure and nutritional value of forage on pastures for grazing animals, thereby reducing the water footprint indicators compared to CON systems. The environmental impacts of rainfall water consumed should not be neglected in water footprint studies due to its importance for restoring water cycles, which is particularly complex in diversified land uses, such as ICL and ICLF. In conclusion, ICL and ICLF are viable production strategies for reducing the environmental impacts of water consumption in grazing-based systems.

SIGNIFICANCE

The research was carried out in the Brazilian Cerrado, a major region for producing and exporting beef cattle in the world and a biome of strategic importance in the water resources dynamics. The region faces significant water consumption challenges because of the accelerated agricultural development disassociated from long-term planning and monitoring of its water resources use. Therefore, our findings are critical in supporting ecosystem resilience and production of beef by also providing insights into the environmental impacts of water consumption in agropastoral and agro-silvopastoral systems, which have been underrepresented in scientific literature.