*2.2.2 Agricultural pollution*

Agriculture is perchance the primeval contribution of man for the survival and prosperity of human kind [14]. Just as agriculture has comprehensively changed the face of the Earth, its impacts have equally profoundly re-wrought the nature of its waters (by degrading both surface and groundwater resources) [15]. These impacts implicate effects on water chemistry, alteration of the hydrological cycles, suspended loads from soil erosion, biocide leaching, and others. Indeed, agriculture can be both cause and victim of water pollution. Since 1990, the connection that exists between land and water use in the agricultural activity is recognized by the Food and Agriculture Organization (FAO) of the United Nations, by its clear requirement "appropriate steps must be taken to ensure that agricultural activities do not adversely affect water quality so that subsequent uses of water for different purposes are not impaired" [16]. The sources of agricultural pollutants could be "point" or "nonpoint" [11, 14, 17, 18]. In fact, water pollution caused by agricultural sources, as nonpoint sources, are hard to supervise and regulate, giving the diffusive nature of agricultural sources. According to Chen et al. [17] the nonpoint source water pollution from agriculture has exceeded that from industry and has become the largest source of nonpoint pollution in China.
