Impact of biological nitrogen fixation and livestock management on the manure transfer from grazing land in mixed farming systems.

Soil fertility in mixed farming systems relies on the manure produced by livestock and its recycling in the entire system. In the particular case of crop-livestock system with grazing area, the proper functioning of the system also depends on the presence of nitrogen-fixing plants in the area where livestock grazes (the grazing land). In this paper, we study the impact of biological nitrogen fixation (BNF) and livestock management on the flux of manure exported outside the grazing land.

Maximization of fertility transfers from rangeland to cropland: The contribution of control theory.

In traditional mixed farming systems, soil fertility in cropland relies on the transfer of fertility from rangeland through the transfer of manure produced by livestock that grazes in rangeland. In this work, we introduce a simple meta-ecosystem model in which the mixed farming system is represented by a cropland sub-system connected to a rangeland sub-system by nutrient fluxes. The livestock plays the role of nutrient-pump from the rangeland sub-system to the cropland sub-system.

Facilitation- vs. competition-driven succession: the key role of resource-ratio.

Symbiotic nitrogen (N)-fixing plants are abundant during primary succession, as typical bedrocks lack available N. In turn, fixed N accumulates in soils through biomass turnover and recycling, favouring more nitrophilous organisms. Yet, it is unclear how this facilitation mechanism interacts with competition for other limiting nutrients such as phosphorus (P) and how this affects succession.

Analysis of arsenic and antimony distribution within plants growing at an old mine site in Ouche (Cantal, France) and identification of species suitable for site revegetation.

One of the objectives of this study was to assess the contamination levels in the tailings of an old antimony mine site located in Ouche (Cantal, France). Throughout the 1.3 ha site, homogenous concentrations of antimony and arsenic, a by-product of the operation, were found along 0-0.