Water, an important element for agriculture

90% of worldwide freshwater consumption is used in agriculture and livestock.

Water is an essential resource for all life, however, only 1% of the total amount of water on the planet is suitable for human consumption, from which a portion of  65% is used in agriculture, making this economic activity the largest consumer of this natural resource.

Agriculture land with irrigation gravity system in Arequipa, Peru. Source: TOXICROP project.

The water used in agriculture comes from a variety of sources such as rivers, streams, canals, ponds, reservoirs, lakes, groundwater from wells, and rainfall. However, due to the increase in human population, there is a greater demand for food, alongside increased exploitation of land for agriculture and water resources for crop growth. The increased demand of freshwater to produce food is contributing to the depletion of this natural resource.

To circumvent the scarcity of water, it is important to implement more efficient irrigation systems and adapt the agricultural practices to the local conditions and water resources available. Furthermore, recycled water is a promising source of water that could also  be used in agriculture and in food production.

Irrigation system

Part of the water utilized for irrigation is returned to the environment as a runoff and eventually reaches the groundwater deposits and surface water with a decreased quality, due to the contamination by fertilizers and pesticides. This issue has been increasing in many areas of the world.

Agricultural production and crop yield are positively affected when water is used efficiently and safely. However, poor quality water can impact agriculture, for example by reducing the nutritional value of crops and affecting crop yield. Water contaminants can also affect soil, making soil less fertile and sometimes toxic to plants. Another major risk, associated with the use of low quality water, concerns the contamination of crops and the subsequent entry in the food chain of dangerous pollutants. The most prominent groups of water pollutants are the industrial chemicals such as perfluorinated compounds (PFCs), polybrominated biphenyls (PBBs), heavy metals, plastics and nanomaterials. Natural toxins, produced by specific groups of microalgae, are also considered very harmful to Humans and cause different types of diseases.

Improving the irrigation system and protecting water quality are essential to avoid the presence of contaminants that can severely damage crop quality and risks to the health of the population and the environment.