28 research outputs found
Changes in soil aggregation and glomalin-related soil protein content as affected by the arbuscular mycorrhizal fungal species Glomus mosseae and Glomus intraradices.
No full textArbuscular mycorrhizal (AM) fungi are key organisms of the soil/plant system, influencing soil fertility and plant nutrition, and contributing to soil aggregation and soil structure stability by the combined action of extraradical hyphae and of an insoluble, hydrophobic proteinaceous substance named glomalin-related soil protein (GRSP). Since the GRSP extraction procedures have recently revealed problems related to co-extracting substances, the relationship between GRSP and AM fungi still remains to be verified. In this work the hypothesis that GRSP concentration is positively correlated with the occurrence of AM fungi was tested by using Medicago sativa plants inoculated with different isolates of Glomus mosseae and Glomus intraradices in a microcosm experiment. Our results show that (i) mycorrhizal establishment produced an increase in GRSP concentration – compared to initial values – in contrast with non-mycorrhizal plants, which did not produce any change; (ii) aggregate stability, evaluated as mean weight diameter (MWD) of macroaggregates of 1–2 mm diameter, was significantly higher in mycorrhizal soils compared to non-mycorrhizal soil; (iii) GRSP concentration and soil aggregate stability were positively correlated with mycorrhizal root volume and weakly correlated with total root volume; (iv) MWD values of soil aggregates were positively correlated with values of total hyphal length and hyphal density of the AM fungi utilized.
The different ability of AM fungal isolates to affect GRSP concentration and to form extensive and dense mycelial networks, which may directly affect soil aggregates stability by hyphal enmeshment of soil particles, suggests the possibility of selecting the most efficient isolates to be utilized for soil quality improvement and land restoration programs
Changes in soil aggregation and glomalin-related soil protein content asaffected by the arbuscular mycorrhizal fungal species Glomus mosseae andGlomus intraradices
No full textArbuscular mycorrhizal (AM) fungi are key organisms of the soil/plant system, influencing soil fertility and plant nutrition, and contributing to soil aggregation and soil structure stability by the combined action of extraradical hyphae and of an insoluble, hydrophobic proteinaceous substance named glomalin-related soil protein (GRSP). Since the GRSP extraction procedures have recently revealed problems related to co-extracting substances, the relationship between GRSP and AM fungi still remains to be verified. In this work the hypothesis that GRSP concentration is positively correlated with the occurrence of AM fungi was tested by using Medicago sativa plants inoculated with different isolates of Glomus mosseae and Glomus intraradices in a microcosm experiment. Our results show that (i) mycorrhizal establishment produced an increase in GRSP concentration – compared to initial values – in contrast with non-mycorrhizal plants, which did not produce any change; (ii) aggregate stability, evaluated as mean weight diameter (MWD) of macroaggregates of 1–2 mm diameter, was significantly higher in mycorrhizal soils compared to non-mycorrhizal soil; (iii) GRSP concentration and soil aggregate stability were positively correlated with mycorrhizal root volume and weakly correlated with total root volume; (iv) MWD values of soil aggregates were positively correlated with values of total hyphal length and hyphal density of the AM fungi utilized.
The different ability of AM fungal isolates to affect GRSP concentration and to form extensive and dense mycelial networks, which may directly affect soil aggregates stability by hyphal enmeshment of soil particles, suggests the possibility of selecting the most efficient isolates to be utilized for soil quality improvement and land restoration programs
INTERNATIONAL CONFERENCE "Soil and Hillslope Management using scenario analysis and runoff-erosion models: a critical evaluation of current techniques" Firenze dal 7 al 9 maggio 2007
No full texttema:
la valutazione critica delle tecniche attuali e dei modelli di deflusso/erosione per la gestione e la conservazione del suolo in ambiente collinare in particolare mediante lo sviluppo di analisi di scenario
Il convegno di terrà sotto il patrocinio dell Commissione europea (nell'ambito del programma COST634).
del CNR- Istituto di Ricerca per la protezione Idrogeologica,
delle università di Bologna e Firenze,
delle regioni Emilia Romagna e Toscana,
delle autorità di Bacino del fiume Arno e del Fiume Reno,
dell'istituto per lo studio e la Difesa del suolo di Firenze.
La web page ufficiale del convegno è la seguente:
http://www.fi.cnr.it/irpi/cost634/index.html
OBJECTIVES & CONFERENCE FOCUS TOPIC
Soils and hillslopes need to be properly managed, understanding process interactions in a way that can be transferred between areas. Feedbacks due to policy and external changes should be estimated in advance through scenario analysis. Usually there is a gap between scientific knowledge, technical tools and the realities to which scenario analysis needs to be applied. The workshop will address these issues in the context of models at all scales.
PROPOSED THEMES AND SESSIONS
session 1 - Models and scenario analysis at farm and catchment scales: Selecting models appropriate for particular areas and problems;
session 2 - Evaluation of model performance: field calibration and validation;
session 3 - Transfer of models to un-instrumented areas: a) are relevant processes described in adequate details?, b) end user confidence in model output;
session 4 - Land use modification and model response: changes in flux connectivity and response times ;
session 5 - Tolerable soil loss: a) Modernising the concept , b) What parameters determine limits?
session 6 - Models to support environmental policy objectives:Scenario analysi
Utilizzazione dell'Isteroscopia nelle donne in menopausa sottoposte a terapia ormonale sostitutiva : studio clinico su un campione di duecentocinquantasei pazienti
No full text
Aggregate water stability of sandy and clayey loam soils differently compacted with and without wheat plants
No full textModeling sediment yields in Italian catchments.
No full textSediment yield observations, derived from 40 long-term sedimentation records in Italian reservoirs, were used to calibrate and validate the spatially distributed sediment delivery model WaTEM/SEDEM using the best data available at national scale. The sediment yield data set includes records from semi-natural catchments in northern Italy as well as agricultural and semi-natural basins in central and southern Italy. The average size of the catchments is 150 km2 with mean annual sediment yields ranging from 0.20 to 20 t ha−1 year−1. WaTEM/SEDEM estimates mean annual sediment fluxes to permanent river channels. Depending on the local transport capacity, the sediment flux is detachment-limited or transport-limited. The optimal transport capacity parameters for Italian conditions were derived via automatic calibration procedures. A global model calibration procedure taking into account all catchments in the dataset led to an overestimation of the sediment yield for the mountain catchments and an underestimation for the non-mountain catchments. Sediment yield estimates are more reliable when calibration procedures are applied separately for mountain and non-mountain catchments. The model performance of WaTEM/SEDEM is rather poor in the mountain catchments (R=0.25), which suggests that the model structure is too simplified to come to an adequate description of the sediment fluxes. The model performance for the non-mountain catchments, which are more important from a management point of view, is significantly better (R=0.51). Considering the fact that data layers with a 75×75 m resolution were used, the results are encouraging the further development and application of spatially distributed sediment yield models at regional and national scale levels
