Azione B6: Monitoraggio sul campo delle emissioni di N2O mediante i due prototipi
Durata: Le campagne di monitoraggio sono state effettuate per due anni, da ottobre 2013 a ottobre 2015. In questo modo, è stato possibile raccogliere dati su due cicli colturali sia per le colture invernali che per quelle estive.
Scopo: In questa azione, la strumentazione realizzata da West Systems è stata utilizzata per monitorare le emissioni di N2O dal suolo sulle prove sul campo opportunamente disposte presso i centri sperimentali CIRAA e CATES. Gli obiettivi di questa azione sono i seguenti:
1) Realizzare il monitoraggio dei flussi di N2O mediante i due prototipi sui campi sperimentali. La stazione di monitoraggio in continuo viene posizionata in CIRAA per il monitoraggio delle variazioni temporali, mentre lo strumento trasportabile sarà utilizzato in entrambi i siti per effettuare il monitoraggio delle variazioni spaziali delle emissioni.
2) Realizzazione di un modello per la stima annuale delle emissioni di N2O a scala di campo, da utilizzare successivamente per l' analisi a scala regionale ( Azione C.2).
3) Valutazione dello strumento trasportabile, in termini di portabilità e facilità d'uso in condizioni di campo. Ciò include la possibilità di effettuare misure in campo senza distruggere o danneggiare la crescita delle colture .
Partner Responsabile: SSSUP
Stato dei Lavori: le attività di monitoraggio biennale con lo strumento trasportabile e con la stazione di monitoraggio continuo sono state concluse. Attualmente sta procedendo la fase di elaborazione dati e redazione del Report sulle attività di Monitoraggio per il secondo anno. Tali attività verranno concluse entro Aprile 2016.
Action B6: Field Monitoring of N2O by means of the two prototypes
From October 2013 to October 2015
In this action, the two prototypes developed by West Systems will be used to monitor the N2O emissions from soil in the field trial suitably arranged at CIRAA and CATES experimental centres (described in action B5), taking into account previous knowledge. Indeed, most studies have shown that soil conditions, such as water filled pore spaces, temperature, and soluble carbon availability, have a dominant effect on N2O emissions. Also fertilizers sources and crop management may affect N2O fluxes. When nitrogen is applied above the economic optimum rate or when available soil N (especially in nitrate form) exceed crop uptake, the risk of N2O emissions rises. The objective of this action will be:
1) to carry out a monitoring campaign on N2O fluxes by means of the two prototypes in the set-up experimental fields (action B.5). The fixed prototype will be placed at CIRAA for continuous monitoring, while the portable prototype will be used in both sites. In this way, it will be possible to monitor the temporal (automatic chambers) and spatial variation of N2O fluxes from soil (portable prototype). The portable prototype will allow monitoring in the same time period many crops with different management practices, characterized by different nitrogen fertilization and irrigation level, in order to test the difference in the emissions of different crop managements. Collected data, referred to Tuscany environmental conditions, will be used to draw up the Best Practices Manual for N2O emissions mitigation in agriculture (Action B.7).
2) to validate a model for annual nitrous oxide emission estimate at field scale, to be used afterwards for the regional scale analysis (Action C.2). Among the existing software codes, the DeNitrification-DeComposition (DNDC) model will be selected as it was already validated under Italian environmental conditions and it is, at present, the best process-oriented model to simulate N2O emissions from cropland. In addition, the DNDC model seems to be particularly suited for the project goals as it addresses both field and regional scale analysis. In all the available models, soil water content, temperature, nitrate and ammonium contents are considered as determinant parameters for N2O emission levels.
3) to evaluate the portability in the field of the portable prototype. A condition that must be respected by the portable prototype is its portability and ease of use under field conditions. This includes the ability to make measurements in the field without destroying or damaging the crop growth.
The monitoring campaign will begin as soon as the two prototypes will be validated by INRA in Grignon. It will be carried out for two years, presumably from October 2013 to October 2015. In this way, it will be possible to collect data on two crop cycles for both winter and summer crops.
At CIRAA and CATES, the study will be carried out on at least 3 food crops and one no food crop (energy or fiber crop) selected following the criteria reported in Action B5. The field trials will be set up on an area about 0.5 ha for each crop. Several treatments will be analyzed with the aim to identify the best crop management in order to reduce N2O soil emissions under the Tuscany environmental conditions. The main analyzed treatment will be: soil type (clay or silty loam), adopting a surface of about 2500 m2 for each of them; irrigation level (0% of Potential Evapo-Traspiration (ET0), 25% ET0, 50% ET0 and 75% ET0 and 4 levels of nitrogen fertilization. These have been identified in scientific literature as the main factors affecting N2O soil emissions and for each treatment levels have been chosen following the common agricultural practices in the study area. Finally, to have significant data, each treatment will by replicates at least 3 times in space and the field trials will be carried out for two years. Subsequently, the minimum number of plots for each crop will be 54, obtained from the experimental design previously described.
Taking into account that not all crops need irrigation (e.g wheat or alfalfa), some modification on the treatments will be done. In addition, some secondary treatments could be analyzed: soil tillage (e.g. conventional tillage, minimum tillage or no tillage); fertilization type (organic or synthetic fertilizers), etc. Anyway, these field trials could be modified in relation to the selected crop, to the analysis of available literature and to the political interest of Tuscany Region. Indeed, the general aims is to investigated N2O emissions trend in cropping systems having a crop management as much as possible close to the more representative in the study area and to obtain suitable data for the territorial analysis.
Expected results
The results of this action, related to the aims exposed above, will be:
1) N2O emission data extending over a period of 2 years for the main winter and summer crops representative of the Tuscany agriculture, in two different climatic conditions, such as coastal and continental environments. The data will be referred to the business as usual management and to alternative management practices to identify the best strategies to reduce N2O emissions in Tuscan environmental conditions. These results, together with literature data on N2O emissions for Mediterranean croplands, will allow the elaboration of a good practices manual to mitigate N2O emissions from agricultural soil.
2) the validation of a model for annual N2O estimate at field scale; upscaling at regional level will allow to evaluate the effects of the adoption of the best practices and to assess the impact of different management strategies Action C2).
3) the field testing for easiness of use of the portable prototype complete of the light vehicle; this will allow to identify the suitable adjustment to be done.
4) the sections of the prototype user's manual relating to field monitoring: the manual will report useful information for technical staff of public and private environmental agencies involved in N2O emission monitoring. The main aspects dealt with in this report will concern monitoring methodology (number of stations per unit area, measurement frequency, etc.) and also an economic evaluation of this environmental service (number of persons, involved, hours of work, instrument maintenance cost, etc.; see Action D4).
