Some considerations: Strengths and weaknesses of LCA of soybean
Even though the carbon footprint (also referred to as climate change or global warming impact) is by far the most well-known impact category, LCA goes much further than that. It includes many other categories that capture significant environmental issues, such as water consumption, fine particulate matter formation, acidification and eutrophication. This generates a complete picture of the impact of a product or process on the environment and allows for a balanced comparison of the environmental impact of different products. It is possible to aggregate several of these environmental impact categories (into so-called endpoint categories, such as biodiversity), to get a complete overview of the environmental impact.
However, it should be borne in mind that LCA can only provide an approximation of the environmental impact, and is only as good as the data that used. Detailed and accurate data will result in robust impact results, but where data are lacking assumptions must be made (e.g. using background data or estimations), which affects the quality of the results.
Despite the many impact categories to choose from in LCA, not all environmental issues are yet covered, such as soil degradation. Reduced inputs of mineral or organic fertilisers would lead to a low footprint, however the resulting depletion of soil nutrients would be unaccounted for.
Soybean cultivation is most efficient in tropical regions. The high carbon footprint of soy production in these regions could lead to expansion of soy cultivation into areas that are less suitable for soy or to the cultivation of alternative crops that are less efficient.