Ecological Footprint

Agriculture has brought about widespread environmental degradation, with this degradation intensifying as it became increasingly mechanized and reliant on man-made inputs. It is therefore important to bear in mind the potentially negative impacts that intensified farming practices will have on ecosystems in areas where organic material for biofuel production is being grown, often where less-intensive agricultural methods have previously been employed, such as in the developing world. This is because the exploitation of biofuels, being made from organic mate­rial, has the potential to have a number of significant negative effects on ecol­ogy. In this section, the impact of biofuels from an ecological perspective will be explored, particularly as a result of unregulated use of (1) herbicides, pesticides and fertilizers, and (2) land-use changes.

4.1 Broader Impacts of Herbicides, Pesticides and Fertilizers

The growing of crops is made problematic by pests, which can destroy whole fields of crops. To enhance productivity and ensure saleable crops in sufficient volumes, pesticides are regularly used to keep unwanted organisms under con­trol. Yet pesticide run-off from agricultural land has the potential to pollute local watercourses and can result in a loss of biodiversity when food supplies for higher organisms are reduced (Charles et al. 2009). This is especially the case with respect to insects, many of which are highly detrimental to agricul­ture, but are of vital importance to creatures higher up in the food chain. The presence of harmful chemicals found in pesticides can also flow throughout food chains, thereby leading to chemical build-up in higher organisms, espe­cially avian fauna, and raptors in particular, the strength of whose eggs is affected by chemicals such as DDT, thereby leading to greater infant mortality (Sodhi et al. 2011).

Furthermore, production processes and distribution relating to pesticides, her­bicides and fertilizers can also contaminate water supplies, something of especial importance in developing nations such as India, where clean, disease-free reticu­lated water might not be readily available to all citizens (Rajagopal 2008). With respect to water, Eisentraut (2010, p. 10) notes that, while water requirements for second-generation crops could be less than for first-generation biofuels, depending on the crop type and local environmental conditions, the total demand for water could be higher owing to additional water treatment steps in the production pro­cess. In addition, run-off from nitrogen-rich fertilizers can profoundly increase the incidence of algal bloom in freshwater aquatic environments. Such outbreaks can result in these watercourses becoming starved of oxygen, while the presence of thick layers of light-seeking algae at the surface of the watercourse can block out sunlight and impede the ability of other plants to photosynthesize effectively (Bergkamp et al. 2000). The result can be a catastrophic loss of biodiversity in affected watercourses, particularly when organisms at the lower end of the food chain are threatened. In many cases, watercourses have become depleted of oxy­gen owing to algal blooms, thereby creating hypoxic or ‘dead’ zones where only a few organisms can survive (Dale et al. 2010).

The use of fertilizers can also result in the acidification of soils (Eisentraut 2010). The phosphorus, nitrogen and potassium contents in fertilizers, when they become dissolved in water, alter the pH balance of the soil. High acidity reduces the functioning of nitrifying bacteria responsible for the breakdown of organic matter into ammonium and nitrate for plant uptake. This might not be problem­atic for biomass cultivation, depending on the species being cultivated, but could have disastrous impacts in adjacent areas affected by fertilizer run-off. Finally, the very production of fertilizer and its distribution are generally energy inefficient. In most countries, it is reliant on carbon-based forms of energy and therefore contrib­utes to GHG proliferation, all of which, as noted previously, needs to be taken into account in an overall LCA.

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