ABSORPTION OF MACRONUTRIENTS AND SODIUM BY TOMATOES SUBMITTED TO NORMAL AND WATER-DEFICIENT IRRIGATION SCHEMES USING VARIOUS CONCENTRATIONS OF WASTEWATER

Abstract

The high, worldwide demand for water use in economic development and domestic consumption has led to studies on the agricultural use of wastewater that can help minimize the problem of scarcity of this resource. This study aimed to evaluate the absorption of macronutrients and sodium by cultivated tomatoes irrigated with wastewater under normal and water-deficient irrigation schemes. The experiment was conducted in a protected environment; we used a drip irrigation system that was managed based on evaporation from a Class A tank placed in the experimental area. Two slides were determined (70 and 100% of the crop evapotranspiration); supply water and four dilutions of domestic treated sewage were used: 25, 50, 75, and 100%. We evaluated the absorption of macronutrients and sodium via chemical analysis of the leaves and fruits. Results showed that plants irrigated using the water-deficient scheme absorbed more nutrients (i.e., N, K, Mg, and S) than those that were treated under the normal (i.e., not water-deficient) scheme. However, the higher the percentage of wastewater used for irrigation, the higher the absorption of sodium by plants and fruits.

Keywords: Nutrition, domestic reuse, irrigation management, Lycopersicon esculentum L.