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The role and importance of organic matter recycling for a sustainable development of agriculture is a challenging subject because, nowadays, it cannot be merely faced through its a agronomic aspect. Organic amendments have got an impact on physical, chemical and biological fertility of soils, especially in Mediterranean regions which have been suffering during the last decades a depletion of soil organic matter content, but their application to land must be evaluated in term of sustainability. A considerable amount of research has been out in Europe in order to evaluate the effects of the application sewage sludge on soil properties, because while the major plant nutrients added with sludge are subject to crop removal and leaching, heavy metals will remain in the soil for a much longer period of time.

The aim of this work was studied the residual effect from sludge amended soil on nutrients and heavy metals uptake by Winter wheat grown on a plot experience located in the province of Madrid, Spain. A loamy clay soil was used from eight long-term field experiment, that was treated with two sewage Sur and Viveros from Madrid waste water treatment plants, in two rates 50 and 100 t ha-1y-1. One control test without fertilizer and another one with a basic inorganic fertilizer, similar to the lower sludge rate in terms of N, P and K. The production and heavy metals residual accumulated in soil and uptake by plants were examined. Productivity studies showed that there werent differences between treatments and there were significant differences between the time and the time-treatment relation (process GLM, SAS/STAT). Essential nutrients and heavy metal concentration in grain and straw of wheat was studied as well. The results obtained for essential nutrients were higher for wheat amended with sewage sludge but there werent significant differences for the doses applied and sewage sludge used.

Finally, only a significant increase of the level of heavy metals in grain and straw were detected but these values were always below Spanish and European legal limits for application of sewage sludge.