GLOBAL WARMING AND AGRICULTURAL ACTIVITIES

Since millennia the Earth is under a natural and slow heating. From the Ice Age to before Industrial Revolution this process did not cause worry. However, from 1990s it was observed an acceleration of this phenomenon together with increase in concentration of gases in the Earth, which reflect infrared radiation back to surface of the planet. Main are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorcarbons (CFCs), hydrofluoroethanes and hydrochloroethanes. Actually, global warming is considered a result from intensification of human activities on the Earth. Concerning to agricultural activities, main released gases are CH4 and N2O. Methane is emitted by enteric fermentation, by arable soils, wetlands, swamps, degradation of organic matter and manure, rice paddies, by underwood in flooded fields, sludge accumulated on floor of rivers, water reservoirs and lakes. Nitrous oxide is released, mainly, by soil bacteria in nitrification/de-nitrification reactions. Reducing methane and nitrous oxide emissions by agricultural activities represent a complex task and it will be only achieved by integrating many intelligent strategies, some have been briefly described in this book.