Carbon and nutrient contents in residues of pineapple crops fertigated with treated wasterwater

Abstract

The use of treated wastewater in agriculture is a viable alternative to produce foods, which can reduce production costs in pineapple crops by substituting partially irrigation and meeting the plants' nutritional demand. This management can increase yield and plant residue and soil nutrient contents for subsequent crops. The objective of this study was to evaluate carbon and nutrient contents in residues of pineapple crops fertigated with treated wastewater. The experiment was conducted using a randomized block design with four replications, in a split-plot arrangement. The plots consisted of five treated wastewater rates: 0, 100, 200, 300, and 400% of the maximum annual limit of Na applied to the soil, which corresponded to irrigation water depths of 0, 117.3, 234.1, 351.4, and 468.3 mm, respectively. The subplots consisted in three pineapple cultivars: Pérola, Smooth Cayenne, and IAC-Fantástico. The treatments with treated wastewater doses had no effect on dry weight accumulation, and content and accumulation of organic carbon, macronutrient, and sodium in pineapple crop residues. Pineapple plants of the cultivar Pérola have lower dry biomass and carbon accumulation than those of the cultivars IAC-Fantástico and Smooth Cayenne.