Water used for irrigation can contain high levels of nutrients; some of these nutrients are beneficial for the plants watered, but can also lead to extensive algal growth.
Algae in irrigation reservoirs can clog the irrigation system and can also be spread over the irrigated area. In addition, some types of fungus also present in these waters can be extremely harmful for the plants grown.
Almost 60 percent of all the world’s freshwater withdrawals go towards irrigation uses where landholders use water basins and farm dams to irrigate their crops. Irrigation water is vulnerable to blue-green algal bloom- particularly during peak summer months. Because of an algal bloom, the water source may become contaminated. It is recommended to avoid the use of contaminated water since it can have a negative impact on humans’ health.
Care must be taken in the use of algicides, as with the use of any aquatic herbicide. Algicides cause cell rupture, and intracellular toxins will be released into the environment. Often these algicides have restriction periods for different uses of the water, such as watering livestock or irrigation. According to the Organization for Economic Cooperation and Development (OECD), 47 percent of the world population could be living under severe water stress by 2050. Therefore, the agriculture industry needs new technologies that allow farmers to increase their water use efficiency.