Recycling of municipal and industrial organic wastes in agriculture: Benefits, limitations, and means of improvement

Abstract

There are various reasons for improving the recycling of municipal and industrial organic waste on agricultural land. These include:- Benefits to crop production due to the recycling of organic matter and mineral nutrients, and possible suppression of soil-borne pathogens.- Conservation of naturally available but limited supplies of nutrient resources.- Avoidance of alternative disposal methods which are environmentally damaging, expensive, or limited by space.A prerequisite for agricultural utilization of organic waste as fertilizers is an effectiveness of the containing mineral nutrients and/or the soil improvement. Over-application increases the potential for nitrogen mineralisation with time and the risk of nutrient losses. In order to avoid this, application rate of organic waste has to get limited. Other problems involved with the application of organic wastes are: greater management difficulties regarding optimized nitrogen supply to plants compared with mineral fertilizers; the possible contamination with environmental pollutants such as heavy metals and organic toxics: hygienic aspects: high contents of extraneous materials. Consequently a comprehensive legal framework for the use of municipal and industrial organic wastes in agriculture must take into account the use of fertilizer depending on nutrient demand, the necessity to avoid the input of contaminants into the soil and the food-chain and the maintenance of quality control.An increasing problem in densely populated industrial countries is that lack of land area often does not allow for the proper application of organic waste fertilizers.