The use of more efficient fertilizers, including inhibitors of nitrification, or conservation agriculture techniques allow long-lasting soil fertility consequently reducing the impact on the environment. More than 20% of global greenhouse gas (GHG) emissions come from agriculture. With the aim of increasing productivity and reducing environmental impact, today´s agriculture is challenged to reduce gaseous emissions associated with agricultural intensification such as N2O, CO2, CH4, NOx and NH3. For over a decade, the group of Agroecosystems Pollution by Agricultural Practices (COAPA) of the Technical University of Madrid has been developing new ways to increase the efficiency of fertilizers including inhibitors of nitrification and urease, which reduce gas emissions significantly [1] with no effect on crop production [2]. COAPA is also working towards the determination of the emission factors -number of pollutants emitted into the atmosphere per unit of activity- in different types of crops and agricultural management practices; an important challenge for Mediterranean agroecosystems. Other research groups such as Agricultural Systems (AgSystems) and industries like EuroChem Agro -which provide important funding for the development of these studies- also collaborate together on the development of enhanced efficiency fertilizers, allowing easy transfer of knowledge to the industrial sector.

 

Another important factor are nitrogen losses by nutrient leaching that cause problems of eutrophication of water bodies and represents one of the greatest environmental problems created by our intensive agriculture [3]. Conservation agriculture and cover crop techniques can improve the use of nitrogen in agricultural systems mitigating diffuse pollution problems and maintaining production and quality of crops. In this regard, studies by Agricultural Systems (AgSystems) and IMIDRA groups have shown that the use of cover crops (intercropping) in irrigated crops and olive groves allow control of soil erosion, controlling nitrate leaching and enabling its use as green manure or forage harvesting; promoting more sustainable production. Meanwhile, management practices such as control of tillage intensity, crop rotation (including legumes and cover crops), application of waste and organic fertilizers are strategies being promoted from Institutions in order to improve the use of nitrogen and sustainability of farming systems. These are the main focus areas of the research groups Soil Quality and Environmental Applications (CASAM) and Soil Conservation and Management – Crop Production (COSVE) whose work has shown that techniques such as direct seeding or tilling improves soil quality -chemical, biological and physical- and reduce proliferation of weeds. It is also important to understand the dynamic of nitrogen entry and assimilation providing diagnostic tools by modelling to adjust the nitrogen input (organic and inorganic fertilization) that crops demand, as indicated by the modeling work carried out by COAPA and AGSYSTEMS. In view of this, AGRISOST consortium develops different methodological approaches with the aim of defining agricultural practices that reduce nitrogen losses and emissions of greenhouse gases without any effect on soil fertility.

[1] Menéndez, S., Merino, P., Pinto, M., GonzálezMurua, C., Estavillo, J. M., 2009. J. Environ. Qual. 38, 2735
[2] Abalos, D., Sanz-Cobena, A., Misselbrook, T., Vallejo, A., 2012. Effectiveness of urease inhibition on the abatement of ammonia, nitrous oxide and nitric oxide emissions in a non-irrigated Mediterranean barley field. Chemosphere 89, 310-318
[3] European Commission, 2000. Council directive of 23rd October 2000 establishing a framework for community action in the field of water policy (2000/60/ec).Official Journal of the European Community (22/12/2000 L2327/2001 to 2073)