ABSTRACT
Agricultural soils constitute natural, fragile and very complex ecosystems where physical, chemical and biological phenomena occur. This universe of physicochemical and biological processes perfectly integrated to produce crops and sustain life is heavily and continually impacted by human activities. As a result of industrial activities, mining and intensive agriculture, soil holds a wide variety of environmental pollutants that threaten its quality and fertility. Likewise, excessive land cultivation, soil compaction, monoculture, and stubble burning also contribute to degradation of soil quality. Accordingly, several soil conservation measures or bioremediation practices have been implemented in order to reduce the impact of unsuitable land management practices and recover degraded soils. Soil amendment with organic wastes such as cattle manure and sludge from sewage treatment plants is a common agricultural practice to combat the loss of soil organic matter and stimulate microbial communities (biostimulation). This chapter deals with the importance of organic carbon to soil function and the beneficial effects of several organic wastes from municipal wastewater treatment plants, salmon plants and paper-pulp industry on soil fertility.
