The issues of energy and carbon cycle: new perspectives for assessing the environmental impact of animal waste utilization.

This paper focuses on the benefits of an efficient use of animal waste from the standpoint of curbing the rise of anthropogenic carbon dioxide (CO(2)) in the atmosphere. An effective use of animal waste resources might provide a partial, but still important, contribution in reducing net CO(2) emissions. In particular: the fulfillment of nutrient requirements of crop plants growing in non-limiting conditions and thus sequestering CO(2) at their potential level; the chance of diminishing the use of fossil energy, and related CO(2) emissions, required for manufacturing industrial fertilizers; the possibility of enhancing carbon sequestration in agricultural soils by the application of farmyard manure. The future success of agriculture in providing these ecosystem services can only be achieved with a changed social awareness of the links between sustainable land use and global environmental change.