International Journal of Agriculture and Crop Sciences.
Available online at www.ijagcs.com
IJACS/2012/4-23/1812-1816
ISSN 2227-670X ©2012 IJACS Journal
Influence of EDTA and Phosphorus Levels on Dry
Matter Yield and Metals Relationships of Maize
Root and Shoot in a Lead-Polluted Calcareous Soil
R. Ghasemi-Fasaei, A. Ronaghi, K. Metanat
Department of Soil Science, College of Agriculture, Shiraz University, Shiraz, Iran
Corresponding author email: ghasemif@shirazu.ac.ir
ABSTRACT:A greenhouse experiment was conducted to investigate the influence of ethylene diamine
tetra acetic acid (EDTA), and phosphorus (P) levels on the dry matter yield and metals composition of
maize root and shoots in a Pb-polluted calcareous soil.Application of P levels increased root dry
weight of maize in the absence or the presence of EDTA. Application of most P levels increased shoot
dry weight of maize. The effect of EDTA on root and shoot dry weight of maize was negligible. No
definite trend was observed in the rates of Cu, Mn and Zn uptakes of maize root following P addition.
Overall, EDTA addition increased Cu, Mn and Zn uptakes of maize root in most observations.
Significant correlation coefficients were observed between Pb uptake with the uptakes of Mn, Zn and
Cu in maize root demonstrating the presence of the synergism between the absorption of Pb with
those of Zn, Cu and Mn. Shoot dry weight showed negative correlations with Pb concentration and
uptake of maize shoot demonstrating the negative influence of Pb entered into maize shoot on the
growth and development of maize tissues. Unlike to root, there were no significant correlations
between Pb uptake with the uptakes of Zn, Mn and Cu in maize shoot demonstrating the dissimilarities
in the translocation from root to shoot of Pb with Zn, Cu and Mn. Root Pb uptake was significantly
correlated with shoot Pb uptake which revealed that Pb translocation from root to shoot increased as
the amount of Pb absorption by root increased.
Keywords: Lead, EDTA, metals, phosphorus, maize
INTRODUCTION
Entering increasing quantities of metals to soils throughout agricultural, industrial, and mining activities
is of great concern owing to its harmful effect on food chain. These soil pollutants are concerned from both
agricultural and environmental standpoints (Papazoglou et al., 2007; Sanchez-Camazano et al., 1998). Lead
(Pb) is a heavy metal which is among the major environmental pollutants (Sari et al., 2007). This metal is
mainly accumulated in surface soil due to its strong association with soil constituents (Banuelos and Ajwa,
1999).
The addition of chelating agents including EDTA is a useful method to increase metal bioavailability
especially in metal-polluted soils (Ghestem and Bermond, 1998). Manouchehri et al. (2006) stated that EDTA is
a powerful chelating agent which is used extensively in soil researches and due to its non-selective nature, the
co-dissolution of trace and major metals could occur following the use of this extractant. According to the
findings of various researchers EDTA addition increased Pb contents of plant (Huang et al., 1997; Wang et al.
2007; Lim et al. 2004; Usman and Mohamed, 2009). Blaylock (1997) observed that addition of chelator
increased the uptake of metals including Pb, Zn, Cu, Ni and Cd. Usman and Mohamed (2009) found that EDTA
addition was an effective treatment in increasing the concentration of Zn, Cu, Pb and Cd in corn and sunflower.
Luo et al. (2005) believed that the effectiveness of chelates in increasing the contents of metals in plants was
consistent with their abilities in solubilizing metals in soils.
It has been shown that P addition to Pb contaminated area can decrease the bioavailability of this
metal to plant (Basta and McGowen, 2004). It appears that the amount of P which is available for the
immobilization of Pb depends on the solubility of P source and P retention capacity of the soil (Park et al.,
2011). Li et al. (2007) reported that the concentrations of microelements in crops were strongly affected by