From Soil to Factory Gate: Cradle-to-Gate Life Cycle Assessment of Sri Lankan Tea

This study conducts a cradle-to-gate Environmental Life Cycle Assessment (E-LCA) of tea production in Sri Lanka, comparing smallholder and estate-owned plantations processed by Orthodox and Crush–Tear–Curl (CTC) methods. Unlike most tea LCA studies that treat cultivation as a single undifferentiated phase, this work explicitly incorporates the perennial nature of tea by using a modular life cycle framework that separates the agronomic stages alongside factory processing up to the packed-tea gate. This approach allows a more precise allocation of long-term environmental burdens over the entire productive lifespan of the tea plant, addressing a methodological gap in the literature. Four production scenarios were evaluated: Smallholder-Orthodox, Smallholder-CTC, Estate-Orthodox, and Estate-CTC, with the functional unit set to 1 tonne of processed tea. Primary data were gathered through structured surveys of 30 plantations (25 smallholders, 5 estates) and 5 tea factories, supplemented by secondary data from Ecoinvent v3.11 and national statistics. The CML-IA Baseline method in SimaPro v9.5 was applied to characterize impacts across eight impact categories: global warming potential (GWP), abiotic element depletion, fossil fuel depletion, acidification, human toxicity, terrestrial ecotoxicity, freshwater ecotoxicity, and eutrophication. Results indicate that Smallholder-Orthodox systems have the highest GWP (3304 kg CO2 eq per tonne), whereas Estate-CTC systems show a lower GWP (2894.87 kg CO2 eq). Acidification potential ranges from 47.21 kg SO2 eq for Smallholder-Orthodox to 41.25 kg SO2 eq for Estate-CTC. Overall, the findings suggest that the scale of plantation management has a greater impact on environmental performance than processing technology, highlighting the need to focus sustainable practices on the cultivation stage, exactly where the perennial crop modeling approach used here provides the greatest analytical benefit.