Irrigation water quality in the Tocantina region of the state of Maranhão, Brazil

Abstract

The population of planet earth is growing every day and, with it, so is the demand for food, energy and fibre. Current FAO estimates suggest that there will be 9.7 billion people by 2050 and 10.9 billion by 2100. Every country in the world is looking internally and externally for solutions to meet this growing demand, and the solutions vary according to their productive, economic and environmental conditions. In Brazil, irrigated agriculture is one of the main strategies for guaranteeing the expansion of agriculture and increasing food production, requiring the consumption of large volumes of good quality water. In view of the above, this study aimed to determine the quality of irrigation water from the main supply sources used in irrigated agricultural crops located in the Tocantina Region of the state of Maranhão. To this end, the parameters pH, electrical conductivity, salinity, temperature and dissolved oxygen were assessed. Of the 10 collection points, only three were outside the pH standards, point P02, P03 and P04. With regard to electrical conductivity (EC), only point P04 showed EC outside the standards. Within the criteria mentioned in the results, only one collection point had a C3 classification (water with high salinity), point P04 had an average EC of 835 µcm-1, which restricts its use in irrigated agriculture.