126 research outputs found
Programma del corso
Programma dettagliato del corso di Coltivazioni erbace
Use of dominance analysis in selecting the best cropping technique based on long term agronomic experiments
Yield averages and variability from three long-term agronomic experiments (LTAEs) have been used in a preference scheme for cropping system options by means of a dominance approach. Preference maps are obtained and include both parametric and stochastic dominance based on yield level and risk for wheat and maize crops grown in the Mediterranean area. Dominance method could add to classic ANOVA the direction of the effect of a treatment and a comparative approach. It allowed comparing technical options and practices on the basis of treatments explored in 3 still running LTAEs: rotation, tillage, mineral fertilisation level and organic amendment
Cenni storici sull’Agronomia e lo studio delle scienze agrarie
La didattica universitaria nel campo delle scienze agrarie necessita anche del richiamo ad alcuni temi di carattere storico, in riferimento alle vicende dell’agricoltura nelle diverse epoche, con particolare attenzione all’evoluzione degli aspetti tecnici e pratici e alle numerose tappe percorse dal pensiero agronomico dall’antichità classica ai nostri giorni. L’auspicio primario di queste pagine è quello di costituire una utile integrazione alle dettagliate nozioni tecnico-scientifiche che caratterizzano i corsi universitari di Agronomia e di Coltivazioni erbacee, non trascurando la possibilità di individuare spunti di approfondimento e temi di ricerca su più ampie questioni di storia dell’agricoltura, e di storia della ricerca e dell’insegnamento universitario in ambito agronomico
Adding Organizations and Roles as Primitives to the JADE Framework
The organization metaphor is often used in the design and implementation
of multiagent systems. However, few agent programming languages
provide facilities to define them. Several frameworks are proposed to coordinate MAS with organizations, but they are not programmable with general purpose languages. In this paper we extend the JADE framework with primitives to program in Java organizations structured in roles and to enable agents to play roles in organizations. Roles facilitate the coordination of agents inside an organization and give new abilities in the context of organizations, called powers, to the agents which satisfy the requirements necessary to play the roles. As primitives to program organizations and roles we provide classes and protocols which enable an agent to enact a new role in an organization and to interact with the role by invoking the execution of powers, and to receive new goals to be fulfilled. Roles have state and behaviour, thus, they are instances of classes and are strictly connected with the organization offering them. Since roles and organizations can be on a different platform with respect to the role player, the communication with them happens via protocols. Moreover, since, besides using protocols, roles and organizations can have complex behaviours, they are implemented by extending the JADE agent class
Crop rotations sustain cereal yields under a changing climate
Agriculture is facing the complex challenge of satisfying increasing food demands, despite the current and projected negative impacts of climate change on yields. Increasing crop diversity at a national scale has been suggested as an adaptive measure to better cope with negative climate impacts such as increasing temperatures and drought, but there is little evidence to support this hypothesis at the field scale. Using seven long-term experiments across a wide latitudinal gradient in Europe, we showed that growing multiple crop species in a rotation always provided higher yields for both winter and spring cereals (average +860 and +390 kg ha(-1) per year, respectively) compared with a continuous monoculture. In particular, yield gains in diverse rotations were higher in years with high temperatures and scant precipitations, i.e. conditions expected to become more frequent in the future, rendering up to c. 1000 kg ha(-1) per year compared to monocultures. Winter cereals yielded more in diverse rotations immediately after initiation of the experiment and kept this advantage constant over time. For spring cereals, the yield gain increased over time since diversification adoption, arriving to a yearly surplus of c. 500 kg ha(-1) after 50-60 years with still no sign of plateauing. Diversified rotations emerge as a promising way to adapt temperate cropping systems and contribute to food security under a changing climate. However, novel policies need to be implemented and investments made to give means and opportunities for farmers to adopt diversified crop rotations
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