Ken Matanachai '22
In the world of agriculture, irrigation has proven to be beneficial to the development and condition of crops. As defined on Wikipedia, irrigation is “the agricultural process of applying controlled amounts of water to land to assist in the production of crops.” Providing a timetable for plants to receive water, irrigation can also lead to a more dependable source of food. Although it seems like an ideal process of farming, there are many drawbacks if not managed properly. These issues can range from damaging land to affecting the health of other people.
Waterlogging and Salinization
Waterlogging and salinization are both negative results of unregulated irrigation. Waterlogging is when a surplus of water in the root zone takes up the oxygen needed for a healthy body of soil. It can typically stem from over-irrigation and improper drainage, causing an excess of water. The effects of waterlogging can include decreased plant growth, root death, nutrient insufficiencies or plant death. Additionally, as an outcome of waterlogging, salinization can occur.
Waterborne and Water-related Diseases
In addition to agricultural impacts, poor irrigation can lead to many various diseases, including malaria and bilharzia. These diseases can spread if there is poor soil drainage or a residue of stagnant water in pits, especially if unsanitary. In order to prevent the harmful effects of water-related diseases, 3 types of solutions are presented. Firstly, proper healthcare must be prepared, secondly, regulating the surroundings to ensure that the diseases do not originate, and finally, reducing human exposure to transmission of these diseases by educating them and improving living conditions. If carried out correctly, the spread of waterborne diseases can be eliminated. For instance, a case in Zimbabwe saw a decrease in infection rate from around 80% to practically nothing.
Impacts of Dams and Reservoirs
In areas with a lack of rain, dams and reservoirs are useful for providing water for farming; however, they also have detrimental effects to the environment. The process of installing a dam can cause fluctuation in the hydrology and limnology of that body of water. In other words, dams can change the flow and distribution of water as well as aquatic life within it, which disrupts the cycle of nature. While necessary for supplying water, dams and reservoirs can decrease the productivity of crops. To sustain flood control, these systems keep water levels down. This attempt of over-flood prevention can be inadequate for certain areas of land as controlled amounts of flooding can recharge soil moisture and increase fertility. Furthermore, because of the ability to change river flow, degradation of water quality, and temperature change, dams and reservoirs can affect the operations of many fisheries. Due to the unsuitable water conditions, fish and many aquatic species are forced to migrate elsewhere. Although it is only an agricultural technique, irrigation has indirect effects on the non-agricultural ecosystems around it.
References
https://www.fao.org/3/w4347e/w4347e10.htm#waterlogging%20and%20salinization
https://www.agric.wa.gov.au/waterlogging/waterlogging-%E2%80%93-science