A new tool for life cycle inventories of agricultural machinery operations

Abstract

The interest in environmental assessments about agricultural processes is fast growing and asking for new tools for accurate impact evaluations. The methodology commonly used to go through these studies is the life cycle assessment, of which the inventory phase (life cycle inventory, LCI) is an essential step. For studies focusing on agricultural productions, the completion of LCI is particularly complex: taking into account the pedo-climatic and mechanical operative variability is evidently difficult. However, the prediction of the environmental impact of mechanical operations caused by the agricultural sector is essential to quantify the impact categories for which it is responsible. A new tool, ENVIAM, was developed to complete LCI to guarantee the availability of local data that describe the mechanical and pedo-climatic conditions occurring in the Po Valley area and widely applicable as well. It calculates mechanical power requests, directly consumed inputs (i.e., fuel, lubricant) and material consumption of a productive system by taking into account soil texture, specific machinery operations and coupling solutions as defined by the user. A subdivision of working time and defined engine load have been considered to calculate fuel consumption; with regard to outputs, exhaust gases emissions from internal combustion engines have been assessed by evaluating the emissive stages of belonging as stated by the EU Directive. A case study was also performed to highlight the differences that occur when an analysis is fulfilled in a context with features different from the average, and resulted in significant variations for the inventory. In more details, a comparison was carried out both with Ecoinvent database and within ENVIAM. With regard to fuel consumption, by changing the soil texture, the analysis showed a range between 64%-184% for sandy and clay soils, respectively, if compared with medium texture ones. With this tool, local contexts defined either as real or as optimised coupling solutions can be investigated to assess their environmental impact.

Keywords

• Agricultural mechanisation
• life cycle inventory
• pedo-climatic variability
• environmental impact assessment.