Nitrogen runoff Increase according to crop scenario for 2016, baseline 2007

Tonnes

9 000 8 000 7 000 6 000 5 000 4 000 3 000 2 000 1 000 0

Corn Belt Northern Plains Appalachian

Lake States Delta

Northeast Southeast

Southern Plains

Source: Mississippi River Task Force, Annual Report, 2009. Figure 3.3.3 Nitrogen runoff

Water quality issues are also important. Fertiliser and pesticides used to cultivate feedstocks, as well as contaminated effluents discharged from conversion plants, can cause increasing levels of pollution to waterways. This may constrain the growth of biofuels production in developed and developing countries with already high agricultural production levels.

An example illustrates the level of nitrogen persistent in various regions of the United States and agrochemical use for different feedstocks.

38 Figure 3.3.4 Agrochemical use in US agriculture

Similarly, agricultural runoff is pervasive in the Mississippi river basin, an area also known as the country’s corn and ethanol belt. Although much of the runoff is linked to corn production for food, feed and fodder, further increases in biofuel crops might cause an overload in runoff into these water bodies to the point where they cannot recover. It is worth noting that a potential collapse of the watershed could occur as a result of the cumulative effects of environmental stress from agricultural production

alone, and not just from biofuels production. This example highlights the need to enact policies safeguarding overall water availability and quality over an entire watershed, promote water-efficient biomass production, and implement water-efficient management methods.