WasteReuse
WasteReuse aims to the development of new and alternative agricultural practices with the use of treated (or potentially untreated) agricultural waste (AW), which affects, besides the production itself, the quality of soil, water and air by considering the effect of the following significant parameters; soil properties, soil-climate relation and environmental conditions.
There exist many projects relative to the development of Agricultural Waste treatment technologies that have been funded within European funding schemes and especially LIFE. Most of them focused on the development of innovative technologies for wastes treatment as well as, for the improvement of production processes which further produce “cleaner” wastes. Apart from European research/scientific communities, there are also companies and individuals (SMEs, environmentalists, etc) who have developed technologies or improved production routes aiming to achieve better quality final products and minimize waste volumes and thus, environmental degradation caused by their disposal.
Treated wastewaters or composted sludges produced by these technologies could potentially be used for irrigation and/or fertilization of crops after evaluation and definition of specific terms and conditions regarding their suitability to support plant growth, without causing phytotoxicity and environmental problems.
Almost all developed technologies include wastewater and/or sludge treatment oriented to safe disposal on land, in aquatic environment or use for irrigation and fertilization. However, in order to use treated wastes with very high content in organic and inorganic constituents in agriculture, a precise and accurate study should be performed including two main end points: soil and crops.
Regarding soil, the continuous disposal of wastes (treated and untreated) may cause severe degradation of the qualitative and fertility properties if specific restrictions and terms are not considered and adapted. Soil properties, like texture, pH, nutrient content and mineralogy play a key role in the potential acceptability of wastes.
Soil is the primary resource for agricultural production and its protection and improvement are essential for agriculture. Application of organic wastes to soil can potentially improve soil conditions and provide nutrients needed for plant production. However, poor methods of organic waste application may cause nutrient loss by runoff and leaching.
These potential non-point source nutrient losses can contribute to environmental degradation, eutrophication of surface waters and possible human health risks.
Because of this growing environmental concern regarding organic waste disposal laboratory and field studies should be carried out prior to use, in order to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. Studies should focus on the effects of waste application on soil nutrient loading, on the development of best management practices for waste application and on the assessment of the impact of waste application on soil properties.
Potential waste pretreatment prior to application as well as their qualitative and quantitative characteristics should be correlated to soil properties. Thus, the ultimate goal should be to apply AW to agricultural land in a way that the soil either filters the potential toxic elements effectively, or electrochemically absorbs them, or decomposes them so that a clean solution infiltrates through soil while simultaneously, soil maintains its absorption capacity to ensure a sustainable system.
As far as crop production is concerned, the tolerance of cultivated crops to applied wastes as well as the application practice should be evaluated in order to allow low input (water and nutrients), high yield, products of high quality, low production cost and consequently an increase in farmers’ income.
An integrated approach is needed in order to establish guidelines, terms and conditions, which will consider soil, cultivated crops, environment and farmers as a system whose components are interrelated and affect each other. This approach could be enabled by collecting and evaluating the results obtained from the up to now completed projects and from other developed technologies.
By categorizing them regarding their suitability for application to different cultivated crops under different soil climatic conditions and by introducing Life Cycle Analysis and Risk Analysis as assessment tools, alternative agricultural practices with the use of treated and potentially untreated AW wastes will be developed in the frame of WASTEREUSE, implemented, demonstrated and widely disseminated.
Moreover, soil quality protection, which is usually ignored, will be considered and recognized as integral part of the developed practices.
Finally, WASTEREUSE will establish specific terms and conditions for the use of AW in agriculture and propose legislative recommendations for AW reuse policy.