RICERCA ITALIANA     

The role of nitrogen fixation of legume crops on sustainable management of the soils

Università degli Studi di Catania

Abstract

The renewed interest in legumes in Europe, as an essential part of sustainable farming systems, is due to their potential to fix nitrogen improving soil fertility and yielding protein alternative to animal protein for ruminant feed-stuffs.



The study of processes and dynamics influenced by crop systems involving legume crop, is justified
By the objective of emphasising adequately yield and environmental potential of these system.
Developed knowledge must to be oriented to the elaboration of crop and agronomic techniques management aimed at obtaining economically sustainable yield and environmental sustainable crop system.



In Italy results of preceding research activities on the same subject are now available. They have shown the best application of the possible techniques to measure N-fixation in field conditions and have quantified N-fixation on forage leguminous.



The actual research is oriented to study the influence of crop system involving legume crop on different soil properties:
- physical aspects;
- nitrogen content and transformation dynamics
- soil organic matter content, repartition, and transformation dynamics
- microbial biomass

Different lab methods will be applied, but especially regarding Nitrogen fixation activity Isotopic Dilution method, largely consolidated for all the involved partners, will be adopted.
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Principal Investigator

Salvatore COSENTINO Universita' degli Studi di CATANIA

Research Objectives

The present project in oriented to the prosecution and to the extension of the research activities and of the related objectives of the two previous projects developed by the same workteam of different Italian University Department.
The actual project is aimed at the reaching of the following objectives:
- Study of Symbiotic Nfixation related phenomena in soil as influenced by crop systems involving legume species;
- Study of soil organic matter in term of total amount, transformation dynamics, different components as influenced by crop systems involving legume species;
- Study of plant residue decomposition dynamics in incubation condition under different temperature and humidity of substrates;
- Study of legume plant / bacteria relations, nodulation activities quantification, bacteria strain characterisation;
- Characterisation of legume plant biomass in terms of phytoestrogen content in relation to genotipical, agronomic and biologic aspects;
- Elaboration of lab protocols for evaluation of soil organic matter and its component, soil nitrogen content and its different form via Nuclear Magnetic Resonance methods aimed at studying their transformation dynamics in the soil as influenced by crop systems in term of crop adopted and agronomic practices invlolved;
- Elaboration of lab protocols for evaluation of soil organic matter extracted and purified from soil coming from different agrosystems and climatic conditions >>>

First Results

- up dated bibliography
- materials and methods and protocols definition
- lab and field analyses procedures definition
At the end of the first work-step, two kind of document will be emitted: Updated bibliography and materials and methods ma

Timescale

24 months

National and international background

The concept of sustainability in the agro ecosystems refers to the conservation of the natural and human sources which allows to obtain the crop productions (Belcher et al., 2004).
Among the natural sources compounding the agro ecosystems the soil source, plays a central role in sustainable approach to the agricultural activity (Warkentin, 1995). This centrality has renewed the interest also of the scientific community on the concept of "Soil Quality", given that soil with adequate properties are able, indeed, to sustain high yield but also to maintain natural equilibrium of the agro ecosystems preserving and improving air and water quality as well (Gregorich et al., 1994).
Soil quality such as previously described is linked to the "dynamic" characteristics considered as variables in a short-medium term and related to the other components of the agro ecosystems with particular reference to the human activities.
The debate on soil quality is still actually oriented on properties or attributes useful to define soil types and to monitor soil quality variations in relation to the crop management adopted (Karlen et al., 1997; Sojka e Upchurch, 1999; Nortcliff, 2002; Wang et al., 2003).
However, studies oriented to detailed quantification and comprehension of the phenomena involved in the systems management influence on soil quality are up to day incomplete.
In this framework special attention have to be oriented to legume crop for their >>>