Assessing life cycle impacts from changes in agricultural practices of crop production

Abstract

Purpose This paper presents an improved methodological approach for studying life cycle impacts (especially global warming) from changes in crop production practices. The paper seeks to improve the quantitative assessment via better tools and it seeks to break down results in categories that are logically separate and thereby easy to explain to farmers and other relevant stakeholder groups. The methodological framework is illustrated by a concrete study of a phosphate inoculant introduced in US corn production. Methods The framework considers a shift from an initial agricultural practice (reference system) to an alternative practice (alternative system) on an area of cropland A. To ensure system equivalence (same functional output), the alternative system is expanded with displaced or induced crop production elsewhere to level out potential changes in crop output from the area A. Upstream effects are analyzed in terms of changes in agricultural inputs to the area A. The yield effect is quantified by assessing the impacts from changes in crop production elsewhere. The field effect from potential changes in direct emissions from the field is quantified via biogeochemical modeling. Downstream effects are assessed as impacts from potential changes in post-harvest treatment, e.g., changes in drying requirements (if crop moisture changes). Results and discussion An inoculant with the soil fungus Penicillium bilaiae has been shown to increase corn yields in Minnesota by 0.44 Mg ha−1 (~ 4%). For global warming, the upstream effect (inoculant production) was 0.4 kg CO2e per hectare treated. The field effect (estimated via the biogeochemical model DayCent) was − 250 kg CO2e ha−1 (increased soil carbon and reduced N2O emissions) and the yield effect (estimated by simple system expansion) was − 140 kg CO2e ha−1 (corn production displaced elsewhere). There were no downstream effects. The total change per Mg dried corn produced was − 36 kg CO2e corresponding to a 14% decrease in global warming impacts. Combining more advanced methods indicates that results may vary from − 27 to − 40 kg CO2e per Mg corn. Conclusion and recommendations The present paper illustrates how environmental impacts from changes in agricultural practices can be logically categorized according to where in the life cycle they occur. The paper also illustrates how changes in emissions directly from the field (the field effect) can be assessed by biogeochemical modeling, thereby improving life cycle inventory modeling and addressing concerns in the literature. It is recommended to use the presented approach in any LCA of changes in agricultural practices.

Accounting for land use changes beyond the farm-level in sustainability assessments: The impact of cocoa production

“…wide range of impacts caused by industrial activities, especially those of highly manufactured products (ISO 14044, 2006;JRC-IES, 2010;UNEP-SETAC, 2016. Despite of this flexibility, existing data and methodological challenges can limit the completeness of LCA studies, especially for value chains that involve agricultural commodities (Curran, 2014;Finkbeiner et al, 2014;Godar et al, 2016;Haas et al, 2000;Kløverpris et al, 2020;Notarnicola et al, 2017;Reap et al, 2008aReap et al, , 2008bRoy et al, 2009). Agricultural practices are highly diverse and their impacts are strongly dependent on contextual factors such as climatic conditions and landscape patterns.…”

Environmental profile of the production of fragrance ingredients used in cosmetic products: comparative analysis of results obtained by life cycle assessment and the green chemistry-based eco-design tool GREEN MOTION™

“…However, alternative agriculture systems, such as organic farming and agroecological systems, are still misrepresented in LCA 54 and further methodological developments are needed to better capture the potential related benefits in LCA. 55,56 Wild plants harvested by hand could be seen as a solution since it is usually considered without impact in LCA, but careful evaluation is needed to avoid potential natural resources overexploitation and biodiversity impacts. The valorization of co-products and the development of a potential circular economy are key levers to lower the environmental impacts of fragrance ingredients.…”

Consequential Life Cycle Assessment of Grain and Oilseed Crops: Review and Recommendations

“…There were three studies from the United States that may be relevant to Canadian conditions. These studies assessed a corn bioenergy policy change [31], the integration of grass-clover and livestock production with a biorefinery [32], and the inoculation of corn with the soil fungus Penicillium bilaiae [33]. The majority of studies (22) focused on European crop production systems.…”