Environmental performance of smallholder dairy farming systems under different levels of technology adoption

Smallholder dairy farming is essential to milk production and rural livelihoods in Indonesia; however, its environmental performance under different levels of technology adoption remains insufficiently quantified.This study aimed to quantify the global warming potential (GWP), acidification, and eutrophication of smallholder dairy farms in Central Java, compare these impacts among technology-adoption categories, and identify production inputs associated with environmental hotspots.A cradle-to-farm-gate life cycle assessment (LCA) was conducted using 1 kg of fresh milk at the farm gate as the functional unit.Primary data were collected from 40 Friesian Holstein dairy farms through field observations, farmer interviews, farm records, and measurements of daily farm activities.Farms were classified into five categories: no selected technology (Category I); using forage chopper (Category II); forage chopper and milking machine (Category III); using biogas (Category IV); and an integrated system combining a forage chopper, milking machine, and biogas (Category V).Environmental impacts were assessed using OpenLCA 2.5, the CML-IA baseline method, and the Ecoinvent 3.10 background database.Data were analyzed using one-way ANOVA, Games-Howell post hoc tests, and multiple linear regression.The mean impacts were 1.94 ± 0.82 kg CO₂-eq, 0.0073 ± 0.003 kg SO₂-eq, and 0.0160 ± 0.008 kg PO₄³⁻-eq per kg milk for GWP, acidification, and eutrophication, respectively.The category V produced the lowest impacts, at 1.16 ± 0.25 kg CO₂-eq, 0.0042 ± 0.0010 kg SO₂-eq, and 0.0095 ± 0.0023 kg PO₄³⁻-eq per kg milk.Biogas adoption alone did not provide the lowest environmental burdens.Concentrate, direct emissions, and detergent use were significantly associated with all three impact categories.In conclusion, integrated technology adoption improves environmental performance more effectively than stand-alone interventions.Policymakers and dairy cooperatives should promote integrated technology packages alongside combines feed efficiency, improved manure management, biogas utilization, and use of environmentally preferable detergents, technical support for smallholders' dairy farmers.