Farm size and tillage technology reveal contrasting modelled patterns in fuel consumption and machinery-related greenhouse gas emissions in Lithuanian crop production

Abstract Fuel use and greenhouse gas (GHG) emissions associated with mechanised agricultural operations depend on both production technologies and farm characteristics, yet these factors are often analysed separately. This study developed an integrated deterministic modelling framework to evaluate fuel consumption and machinery-related GHG emissions from diesel fuel combustion across five tillage systems—conventional plowing (PL), minimum tillage (MT), deep strip-till (DST), shallow strip-till (SST), and no-till (NT) across multiple crop groups and five farm size groups ranging from 30 to 50 ha to > 500 ha under Lithuanian conditions. Fuel consumption was calculated for all mechanised operations using predefined tractor–implement operating parameters, field performance, coefficients, input requirements, crop yields, and transport distances. Machinery-related GHG emissions were estimated from diesel consumption using IPCC emission factors. Soil-derived emissions and upstream emissions associated with the production of fertilisers, pesticides, fuels, and machinery were outside the system boundary of the present study. The results identified contrasting area- and yield-scaled patterns. Fuel consumption and machinery-related GHG emissions per unit area increased across the predefined farm-size scenarios, partly reflecting the assumed transport distances and machinery configurations, whereas fuel use and machinery-related GHG emissions per unit of production decreased as a result of the predefined yield and operational-efficiency assumptions. Across all farm sizes, NT showed the lowest fuel consumption and machinery-related GHG emissions, while PL consistently produced the highest values. Compared with PL, NT reduced fuel use and associated machinery-related GHG emissions by 35–58%, depending on crop type and farm size. The principal contribution of the study is a harmonized scenario-based comparison of tillage intensity, crop group, farm size, machinery configuration, operational logistics, and machinery-related GHG emissions within a single deterministic framework using both area- and output-scaled indicators. This approach enables the magnitude and consistency of machinery-related fuel and GHG differences to be evaluated across production scenarios under a common set of assumptions. The results demonstrate the importance of reporting both area- and output-scaled indicators when evaluating technological scenarios in crop production.