A two year’s field experiment (1995 and 1996) was conducted on a Typic Xerofluvent in order to study the influence of sewage sludge application on corn yield and nutrient uptake. Treatments included control (no sewage sludge, no mineral fertilisation), mineral fertilization (no sewage sludge) and sewage sludge application in total rates from 50 to 130 ton.ha-1 dry sewage sludge, applied gradually during the two years of experimentation. The results showed that sewage sludge application caused a significant increase in corn yield in comparison to control which ranged from 18.1 to 35.8%. Yield increase was attributed to the increase in uptake of N, P, Zn, and Mn.
Application of sewage sludge to agricultural land has been widely adopted in all over the world. In Europe about 40% of the sewage sludge produced is recycled to the land and this percentage is expected to increase (Smith, 1996). That is because sewage sludge contains considerable amounts of organic matter and many elements essential for plant growth. In Greece during the last years waste water treatment plants were established in many cities, even the small ones. Taking advantage from the European Union legislation and the motivations offered, the respective authorities started managing their urban wastes in an environmentally safe way establishing wastewater treatment plant units. So, the total amount of the sewage sludge produced is expected to rise and the problem of managing the sewage sludge produced becomes pressing. Sewage sludge besides the beneficial substances contains also potentially toxic elements and its recycling in agriculture must be made under control and monitoring of its impacts. European Union has imposed limitations in sewage sludge usage that member country has to be followed (EC, 1986). In Greece research related to the influence of sewage sludge application on crop yield and nutrient uptake is limited. So, the main purpose of the present study was to evaluate the application of sewage sludge to corn as a substitute of mineral fertilisers.