Dairy production intensification and environmental impacts in western Buenos Aires, Argentina

Dairy production intensification in the Western Dairy Basin of Buenos Aires, Argentina, may improve milk production efficiency while increasing local environmental pressure. We quantified the carbon footprint (CF), green and blue water footprints, and farm-gate nitrogen and phosphorus balances of 30 dairy farms (July 2020-June 2021), grouped into low, medium and high intensification by K-means clustering on concentrate use per hectare, dry matter intake, stocking rate and milking-cow ratio. Indicators were expressed per unit of fat- and protein-corrected milk (FPCM) and per hectare. Across farms, mean impacts were CF 0.86 kg CO2-eq kg-1 FPCM and 6,579 kg CO2-eq ha-1; N balance 160 kg N ha-1 yr-1 (NUE 25%); P balance 9 kg P ha-1 yr-1 (PUE 57%); green water 1,170 L kg-1 FPCM and blue water 8.68 L kg-1 FPCM. Several indicators differed among intensification groups (p < 0.05), with lower CF and N balance per FPCM but higher emissions, N surplus and blue water use per hectare in the most intensive farms, shifting environmental burdens from product-based to land-based metrics. Concentrate use, stocking rate and dry matter intake were the main leverage points. Given its observational, cross-sectional design and non-random sample, this study identifies associations rather than causal effects of intensification.