INTEGRATED TERRITORIAL APPROACH FOR SUSTAINABLE AGRICULTURE: NITROGEN MANAGEMENT AND SOIL CARBON SEQUESTRATION IN LOMBARDY REGION

In the last years, intensive agriculture and high concentration of livestock activities have become two important environmental concerns, being partially responsible of nitrogen pollution and CO2 emissions caused by carbon loss from soil. That’s particularly true in Lombardy region, due to the presence of more than 27% of cattle and 51% of pigs of the national livestock and due to the extent of area devoted to cereal cropping (about 63% of the utilized agricultural area - UAA). It is also to be remarked that cereals in Lombardy are commonly grown in continuous cropping systems. In this context, the aim to encourage sustainable agriculture led European Union to introduce regulations (e.g. Nitrates Directive 91/676/EEC), to define mandatory standards, and measures (Common Agricultural Policy), to promote the implementation of best management practices. Consequently, assessing the potential effects of different policies, prior to their introduction, has become very important. Several methods (direct measurements, simulation models, simple and composite indicators) have been developed and applied by traditional agronomic research, however there is still a need of up-scaling experimental results from the farm to the landscape scale. Moreover, it has to be taken into account that the impact of these measures also depends on the interaction between type of action, pedo-climatic factors and farm characteristics. An effective tool for territorial management and planning is then particularly needed in Lombardy, since the territorial approaches, supported by robust methodologies (e.g., extensive databases, models and geographical information systems (GIS)), have become more and more central in European policies. The aim of this work is to assess and investigate the important outcomes of a more territorially based approach, analysing the most important environmental issues, related to agriculture in Lombardy: manure management, nitrogen leaching and carbon sequestration by soils. Three examples of tools and applications are presented: i) Decision Support System (DSS) ValorE, to analyse and to evaluate manure management and technological alternatives, available for the entire supply chain from animal feed to the distribution in the field; ii) application of the ARMOSA cropping system simulation model to assess the potential risk of nitrate leaching towards groundwater in 3 Nitrate Vulnerable Zones (NVZs); iii) application of ARMOSA to evaluate carbon sequestration capacity of regional soils, under current and alternative scenarios, focusing the attention on the impact of different spread levels of conservation agriculture. The territorial approach proposed in this thesis, was based on robust methodologies, extensive databases, stand-alone models (e.g. ARMOSA), more complex structures (ValorE DSS) and GIS techniques. All these components led this approach to be an effective solution for investigating and supporting the regional agricultural management, as well as for assessing the potential impact of the regional policies, always keeping in mind that agricultural sector plays a key role in the climate change mitigation and in the environmental protection from biodiversity loss and from N pollution.