In order to implement the European Strategy on the reduction of greenhouse gases' emission of 20-30% in 2020, an important decrease in the output of all these gases from their main sources is needed. Agriculture is responsable in Italy for about 7% of total emissions in 2009, with the main gas represented by nitrous oxide release from soil, with the agricultural contribution corresponding to 70% of total N2O output. Nitrous oxide emissions are mainly due to nitrogen fertilization in cropping systems. At present N2O emissions in agriculture are estimated, both in the regional and national inventories, by using the IPCC guidelines, reporting a simplified model involving the amount of fertilizer applied only and leaving out of consideration other potentially important parameters such as meteorological and climatological conditions and agricoltural management.
Alternatively, N2O emissions may be measured by means of several techniques (see state of the art) but they are either not suitable for croplands (such as the eddy correlation technique) or require the use of a time-consuming procedure involving gas sampling from accumulation chambers and laboratory GC analysis.
Based on previous considerations, in this project we intend to develop a different approach through the on-site determination of N2O fluxes by means of accumulation chambers equipped with continuous N2O analyzers. To this purpose, two different prototypes will be developed, one portable, the other to be used in a fixed site (station prototype). Upon their design, realization, laboratory calibration, and field validation, we expect to be able to measure N2O fluxes directly in the field, in a very short lapse of time, and with better sensitivity compared to other approaches. These aspects are very important to evaluate annual budgets for integrated areas, considering the large spatial and temporal variabilities of N2O emissions. Through a series of carefully planned field trials in two different sites of the Tuscany Region, characterized by distinct pedological and climatic conditions as well as different crop management, we expect to be able to obtain a sufficiently reliable figure for the whole N2O emission from Tuscan arable lands.
The main objectives of this project are:
1) the development of two prototypes for monitoring N2O fluxes, one fixed and the other portable, to measure N2O emissions from soils in order to improve the present monitoring on this greenhouse gas output;
2) the identification of the best agro-ecosystem management practices to reduce these emissions from agriculture in the Tuscany Region;
3) Scenario analysis at regional scale to identify the measures to be adopted as financial incentives for N2O mitigation from agricultural practices.