Phytoextraction and nutritional quality of forages cultivated in a constructed wetland system for wastewater treatment

Abstract

This study aimed to evaluate the effects of different concentrations of sodium on the phytoextraction of nutrients and nutritional quality of forages (P. purpureum Schum and C. dactylon Pers) grown in wetland system constructed for wastewater generated in cattle slaughterhouses (WGCS) treatment. The experiment was conducted in a randomized complete block design with three replications. The treatments were tested using 2 x 5 factorial scheme, as follows: two species of grass (P. purpureum Schum and C. dactylon Pers) and five concentrations of sodium in WGCS: 70, 100, 150, 200 and 250 mg L-1. The phytoextraction potential of nutrients and the nutritional quality of forages grown in pots simulating a wetland system constructed for WGCS with sodium concentrations were assessed in terms of the contents of the nutrients nitrogen, phosphorus, potassium, calcium, magnesium and sodium in leaf tissues. The accumulations of these nutrients in the produced forages were also evaluated. Both species presented different behaviors regarding their nutrient phytoextraction potentials. The nutritional quality was changed in the forages due to the cultivation in constructed wetlands. Forage C. dactylon Pers presented higher phytoextraction potential of sodium and potassium and P. purpureum Schum presented a higher nutritional quality.