Comparison of Chicken Manure and Urea Fertilizers as Potential Soil Amendments for Enhanced Phytoextraction of Heavy Metals

ABSTRACT

Cadmium (Cd) solubilization in soil and uptake by Mucuna pruriens var. pruriens and Sphenostylis stenocarpa was studied in response to the chicken manure and urea fertilizers application types. In this study, 0.8 g each of the amendments was applied to petroleum-contaminated soil in a pot experiment. Results indicate that the chicken manure application at 14 days before planting gave significantly higher shoot dry matter than its urea counterpart under conditions of Cd stress. Chicken manure application resulted in less Cd solubilization as compared with urea fertilizer dosing. The chicken manure application also significantly increased the shoot Cd accumulation despite its lesser effect on Cd solubilization; thus, it is expected to minimize the risk of groundwater contamination. Chicken manure amended treatment showed greater Cd tolerance for the two species investigated and S. stenocarpa did not support Cd phytoextraction. Although the amendments gave marked reduction in Cd phtotoxicity, those of the urea fertilizer gave only rapid, but short, growth support.

KEYWORDS:

• amendments
• cadmium
• phytoextraction
• phytotoxicity

ACKNOWLEDGMENTS

The authors are grateful to the Director and Staff of Shell Petroleum Development Company (Nigeria), Nigerian National Petroleum Corporation, and Central Research Laboratory of the University of Port Harcourt (Nigeria) for their assistance in many ways. Prof. E. O. Ayalogu is appreciated for his technical and advisory assistance in this study.