Agricultural residues management: Life cycle assessment implications for sustainable agricultural practices and reduction of greenhouse gases emissions

The need for food and feed has created immense pressure on agricultural production systems, with emphasis on conventional agricultural practices, especially these that threaten the sustainability of the entire production system. Current cultivation practices are responsible for adding 2.33-12.4 tha(-1) CO2 to the atmosphere. Burning crop residues also adds air pollutants to the atmosphere and causes a significant loss of soil organic carbon and vital plant nutrients. Furthermore, animal-based activities related to manure storage and its application in crops also add approximately 12% GHGs of the total agricultural GHGs emissions. These practices have necessitated the adoption of sustainable agricultural practices which provide soil cover, enhance soil organic matter, C-sequestering, GHG emissions savings and reduce soil erosion such as these that incorporate crop residues into the soil. Agricultural residues are abundantly available and have great potential; if properly used since they can significantly contribute to C-sequestration, GHG emission savings, resulting in a profitable and environmentally friendly agriculture. On average, the crop's C-sequestering potential is reported at 6343.7 kgCha(-1), of which 4030 kg C ha(-1) originate from edible products and 2313.6 kgCha(-1) from crop residues retained in the field. Total GHG emission savings from cattle slurry digestion equals 34kgCO(2) eq. t(-1) of slurry. In another study, 7.7 kgCO(2) ha(-1) yr(-1) GHG emissions savings have been reported due to digestate application in a grassland-based production systems. The present review considers the benefits and significant issues of agriculture residue usage in terms of environmental quality and human health. Life cycle assessment (LCA) of agricultural production systems is also discussed. LCA offers alternatives concerning the suitability of agricultural residues in improving major agronomic and husbandry operations, such as crop nutrition and soil fertility, seed and seed germination, and weed control. They are also indicative regarding the margin in terms of GHG emission savings for improvement of food and agricultural production systems sustainability.