The effect of sewage urban and industrial sludge on the development of wheat and colza

International audienceThe main objective of this study is to evaluate the effect of two types of sludge from sewage treatment urban and industrial plants on the wheat and colza. These sludge is made at different doses (5, 25, 50 and 100 t / ha). We are therefore interested in the growth and absorption of heavy metals by plants and follow the fate of the latter in the ground to prevent pollution events and toxicity. The soil is characterized by an alkaline pH; conductivity ranging from 1.06 to 1.52mmho/cm resulting low salinity and soil saturation is between 30.4 and 31.8ml/100g. The sand is the most representative size fraction in this soil which is a sandy loam soil texture. The percentages of limestone in the different horizons are less than 5% so it is a non-calcareous soil, with organic matter content very low. Contents of total nitrogen are relatively low. The C/N ratio is about 7 at the first horizon (0-10cm) indicates that organic matter will be quickly mineralized. The mean levels of heavy metals found in the soil are organized in the following order: Fe " Mn> Zn> Pb> Cu> Ni> Co> Cd mean concentrations of heavy metals introduced by the sludge