Chapter 9 Agriculture-induced contamination of surface water and groundwater in Portugal

Abstract

From the end of the 1980s, many studies have drawn the attention to the environmental consequences of “industrial agriculture”, namely significant soil erosion and a decrease in water quality. European citizens have demonstrated a growing interest in understanding how their tax money is used in efforts to guarantee the safety and quality of consumer goods and to protect the environment. When Portugal joined the EC in 1986, its main agricultural indices contrasted significantly with those of the other member states. Agriculture made up 12% of gross domestic product, and provided employment to roughly 20% of the active population. In Portugal, the adoption of new technologies, namely improved seeds, higher inputs of fertilizers and pesticides, and mechanization, were introduced later than in other European countries. Sparingly used fertilizers and pesticides partially avoided the negative impact in terms of soil and underground water contamination that took place in many European countries. However, maintenance of the traditional pattern of land allocation to crops had negative impacts in some regions. Extensive cattle breeding in silvo-pastoral systems, low intensity of crop rotation, and excessive tilling resulted in erosion and degradation of soil organic matter with consequent loss of fertility.The adoption of less-polluting farming practices can only be made with the full cooperation of the agriculture community and largely depends on demonstrating both the environmental and economic benefits of such practices to land managers.