Teores de metais pesados no solo e em girassol adubado com lodo de esgoto

Abstract

Objetivou-se, com este trabalho, avaliar os teores de metais pesados no solo e em plantas de girassol adubadas com doses de lodo de esgoto. O experimento foi desenvolvido em Cambissolo Háplico, no período de abril a setembro de 2011. Os tratamentos, distribuídos no delineamento em blocos casualizados, com quatro repetições, corresponderam a um tratamento com adubação química e cinco doses de lodo de esgoto aplicadas com base nos teores de N do resíduo e na exigência de N do girassol (0; 4,84; 9,68; 19,36 e 29,04 t ha-1, em base seca). Os teores de Zn no solo e na planta foram maiores nos tratamentos com a aplicação de lodo de esgoto quando comparados com a adubação química. A aplicação de lodo de esgoto resulta em aumento nos teores de Cu, Ni e Pb no solo e não apresenta influência sobre os teores de Zn, Fe, Mn, B, Cd e Cr neste substrato. Por outro lado, na planta, com o aumento da dose de lodo de esgoto, houve aumento dos teores de Zn, Cu e Mn e redução do teor de Pb.

Residual effect of sewage sludge fertilization on sunflower yield and nutrition

“…The positive effect of sewage sludge in agriculture was confirmed by Nascimento et al (2011), who observed a good response of papaya plants to the increase in sewage sludge doses. These authors also found agronomic efficiency index of 198% for the application of 60 t ha -1 of sewage sludge, compared with chemical fertilization, which evidences the potential of sewage sludge in the improvement of soil physical and chemical characteristics.…”

“…These results corroborate those observed by Barbosa et al (2007) and Zuba Junio et al (2012), who observed a positive response in maize yield to the residual effect of sewage sludge application in the soil. According to Nascimento et al (2014), the increase in the yield of crops fertilized with sewage sludge is due to the improvement in soil chemical, physical and biological quality.…”

“…In addition, it allows the return of organic residues produced in urban areas to the field, increasing agricultural sustainability (Barbosa et al, 2007). However, it has potential risks of soil and plant contamination with heavy metals, pathogenic microorganisms and organic contaminants (Nascimento et al, 2014;.…”

Yield and nutrition of sunflower fertilized with sewage sludge

“…These positive effects are attributed to the supply of nutrients, especially nitrogen, by the residue and to the beneficial effects on physical attributes of soil (Caldeira Júnior et al, 2009;Nascimento et al, 2014).…”

Yield of castor bean fertilized with sewage sludge and potassium and magnesium sulphate

“…However, despite these benefits, the presence of heavy metals, persistent organic substances and pathogenic microorganisms limits its agricultural use (Nascimento et al, 2014a;.…”