Forage and feed crops meeting the challenges of climate change and sustainable agriculture

 

Agricultural production in the Mediterranean basin will be affected negatively by climate change, owing to the predicted greater incidence of drought (determined by less rainfall and higher temperatures) and greater frequency of extreme climatic events (IPCC, 2007). The rising of input costs (fertilizers, tilling, etc.) and the progressive decrease of water available for irrigation can further reduce crop production. While climate change may hasten the trend towards desertification directly and indirectly (e.g. through increased use of saline irrigation water), overgrazing and desertification may in turn contribute to climate change by raising temperatures locally (Nasrallah and Balling, 2004) and by sequestering less carbon dioxide (FAO, 2010).

Nitrogen-fixing feed and forage legumes with genetically-improved tolerance to drought and other major stresses may play a crucial role in strategies of climate change adaptation and mitigation while enhancing the economic and environmental sustainability of Mediterranean agriculture, by:

  • reducing the high greenhouse gas emissions and the energy consumption associated with the industrial synthesis of nitrogen fertilizer (Wood and Cowie, 2004), by means of symbiotically-fixed nitrogen made available to grasses or cereals grown in association and to the following cereal crop in the rotation;
  • imiting overgrazing and desertification, and improving carbon sequestration and soil cover by rotational and permanent grasslands;
  • increasing the resilience and water use efficiency of the crops, as well as their ability to grow without (or with very limited) irrigation;
  • reducing the amount of methane emissions per unit of animal product (milk, meat, etc.), by means of better feed quality, more balanced diets and more productive animals (FAO, 2010);
  • contributing to mixed farming, diversification and flexibility of farming systems, biodiversity of cultivated material, soil regeneration and efficient nutrient cycling (thereby enhancing the resilience of farming systems relative to cereal monoculture-based systems: Olesen and Bindi, 2002);
  • reducing the greenhouse gas emissions arising from feed transport costs;
  • reducing the marked deficit of high-protein feedstuff at the national and farm level and the related feed insecurity, import costs and exposure to feed price volatility (in some cases, feed insecurity may also concern the lack of traceable, non-GM feed protein for organically-produced or typical animal products).