Abstract
The effects of calcium hydrogen phosphate on lead (Pb) uptake by cowpea (Vigna unguiculata) were investigated in a growth chamber experiment coupled with atomic absorption spectrophotometry (AAS) and colorimetry analyses. Cowpea seeds were planted and harvested in soil samples treated with Pb+2 added as lead nitrate at the rates of 0, 1000 and 3000 mg/kg followed by calcium hydrogen phosphate (CaHPO4) at 0, 10, 50 and 250 mg/kg. Increases in shoot yield brought about by phosphate fertilization were observed to oppress the shoot lead concentration as a result of growth dilution, where the actual amount of lead in shoots was unaffected by phosphate treatment. This work revealed that there is no substantial effect on lead uptake by cowpea, as a result of phosphate fertilization. Therefore, phosphate fertilization is a good means of cowpea production with minimal lead uptake and hence safe for human consumption
Highlights
Soil factors controlling lead availability to plants have been well documented
This work is precisely aimed at investigating the influence of phosphate addition to plant, with respect to lead uptake and disorders in physiological activities of the plant caused by the presence of lead
MATERIALS AND METHODS All reagents, lead nitrate and calcium hydrogen phosphate supplied by Merck (Darmstadt, Germany), nitric acid obtained from Thornton and Ross (Huddersfield, England) used in this study were of analytical grade purity and used without further purification
Summary
Soil factors controlling lead availability to plants have been well documented. The elevation of pH promotes the formation of Pb precipitates as hydroxides, phosphates and carbonates, as well as insoluble complexes with organic matter. Organic material associated with the elevation of pH slows the absorption of Pb by plants, as the Pb2+ ion forms complexes with humic compounds of the soil and becomes less available (Kabata-Pendias and Pendias, 2001). The visual general symptoms of lead toxicity are fast inhibition of root growth, underdeveloped growth of the plant, blackening of root system and chlorosis. Let downs mineral nutrition, water balance and enzyme activities (Sharma and Dubey, 2005). These disorders upset normal physiological activities of the plant. This work is precisely aimed at investigating the influence of phosphate addition to plant, with respect to lead uptake and disorders in physiological activities of the plant caused by the presence of lead
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
