The aim of this work was to estimate the emissions in the forage production of dairy farms in Cantabria and their carbon footprint, considering the indirect use of the land and the potential carbon sequestration of plant remains and from the slurry. Sixty dairy cattle farms in Cantabria were classified into three fodder models: i) Grassland (P); ii) Grassland-Maize (PMz) and iii) Grassland‑Maize‑Winter Forage Crops (PMzCFI), in order to estimate greenhouse gases from forage. The forage crops were grass in cattle feeder (HPP); grass silage (EHM) and Italian ryegrass (ERM) in round bale silage; grass silage (EHT) and maize (EMz) in trench. The emissions of P, PMz and PMzCFI were 1519, 1851 and 2382 kg CO_2eq ha⁻¹, respectively; of which, 20.1% come from cultivation operations; 9.2% of consumables and 70.6% of soil. The emissions of forages within the surface that they occupy in one hectare were 515 kg CO_2eq for HPP, 886 kg CO_2eq for EHM, 774 kg CO_2eq for EHT, 747 kg CO_2eq for EMz and 678 kg CO_2eq for HPP. Vegetable remains contributed 2866 kg DM ha⁻¹ and 3769 kg slurry, equivalent to 4580 kg C with a carbon sequestration potential of 458 kg. In general, the carbon footprint of each fodder model without carbon sequestration was 0.219, 0.257 and 0.271 kg CO_2eq kg⁻¹ MS in P, PMz and PMzCFI respectively and between forages of 0.189, 0.266, 0.232, 0.223 and 0.395 kg CO_2eq kg⁻¹ of dry matter for HPP, EHM, EHT, EMz and ERM respectively. The latter decreased to 0.0075, 0.069, 0.036, 0.025, 0.17 kg CO_2eq kg⁻¹ MS for HPP, EHM, EHT, EMz and ERM respectively when carbon sequestration was taken into account. The nitrogen management was the best related variable, whether taking or not into consideration the carbon sequestration. Emissions per hectare increase with intensification, but decrease per kilogram of dry matter produced. The reduction of use of round bale silage (EHM and ERM) by increasing those in trench grass (EHT) may be a mitigation option, with emissions similar to EMz. For the calculation of the carbon footprint, plant residues and slurry must be considered as a carbon sink, which can contribute to compensate 80% of the total carbon emitted in the production of one kilogram of dry matter.

Salcedo G (2020). Emisiones en la producción de forrajes de las explotaciones lecheras. ITEA‑Información Técnica Económica Agraria 116(4): 311‑337. https://doi.org/10.12706/itea.2020.008