Università di Bologna
Dipartimento di Scienze Agrarie
The paper presents the result of an application of the GeoWEPP model in a heterogeneous semi-agricultural catchment located in the northern Italian Apennines mountain range. The objectives were: (a) to evaluate the GeoWEPP model in a... more
The paper presents the result of an application of the GeoWEPP model in a heterogeneous semi-agricultural catchment located in the northern Italian Apennines mountain range. The objectives were: (a) to evaluate the GeoWEPP model in a heterogeneous catchment in a Mediterranean climate and (b) to examine the effect of digital elevation model grid size on hydrological and sediment yield simulations. The catchment is characterized by large heterogeneity in geology, soil type, vegetation cover and topography. In addition, 10% of its area is occupied by calanchi (badlands), characterized by steep, bare soil and accentuated erosion. Experimental streamflow data were compared with those simulated by GeoWEPP for a period of eight years and the results were evaluated by means of statistical indices, with the analysis of the flow duration curve. Simulated sediment yields were compared with experimental data for one year. The streamflow cumulative annual results were satisfactory with NSE oscillating between 0.40 and 0.83 and RMSE between 1.1 and 2.9 mm. Also, the performance of the model with daily streamflow data was positive (NSE = 0.68 and RMSE = 1.9 mm). The flow duration curve indicated that GeoWEPP could represent the experimental streamflow for fluxes over 1 mm d À1 . The model performance for simulation of sediment yield was satisfactory with both digital elevation models of different grid sizes (NSE = 0.84 and 0.87). Indeed, the sensitivity analysis tests of the model showed that there was no statistically significant improvement in the accuracy of the digital elevation model between 10 and 2 m resolution. These results were confirmed for both streamflow as well as sediment yield. Additional sensitivity analysis of other model parameters performed on the entire catchment and badlands hillslopes showed that bedrock hydraulic conductivity primarily affected the model in both settings. Figure 2. Centonara catchment maps: (a) lithology, (b) pedology, (c) digital elevation model (DEM 10 m resolution), (d) land cover. L. PIERI ET AL.
- by Linda Pieri and +2
- •
- Geology
The Shiozawa and Campbell Gaussian bimodal model describes the particle size distribution (PSD) in soils as a weighted sum of two fractions: the primary minerals (sand and silt) and the secondary minerals (clay) fraction, each described... more
The Shiozawa and Campbell Gaussian bimodal model describes the particle size distribution (PSD) in soils as a weighted sum of two fractions: the primary minerals (sand and silt) and the secondary minerals (clay) fraction, each described by a Gaussian function.
- by Marco Bittelli and +1
- •
In this paper, different characteristics of runoff and eroded sediments were investigated as well as changes in textural composition of the original soil, on experimental plots. The objectives were to investigate the particle size... more
In this paper, different characteristics of runoff and eroded sediments were investigated as well as changes in textural composition of the original soil, on experimental plots. The objectives were to investigate the particle size distribution of the eroded sediments, as a ...
- by Marco Bittelli and +1
- •
- Water Erosion, Sediment Yield
The Water Erosion Prediction Project (WEPP) model was tested using data from a detailed study conducted on experimental plots in the Apennines Mountain Range, northern Italy. Runoff, soil water and sediment data, together with weather... more
The Water Erosion Prediction Project (WEPP) model was tested using data from a detailed study conducted on experimental plots in the Apennines Mountain Range, northern Italy. Runoff, soil water and sediment data, together with weather information, were collected on an hourly basis at the study site. WEPP was first applied to simulate transient surface runoff, soil water and erosion. Two important input parameters, the biomass energy ratio for crop and the effective hydraulic conductivity of surface soil, were calibrated using field-observed runoff, soil water, erosion and plant biomass data. The calibrated model was then used to simulate the hydrologic and erosion impacts of three typical crop rotations, thereby to evaluate their abilities in reducing surface runoff and sediment yield. Results indicated that, with the definition of a restrictive layer at the bottom of the soil profile and the calibration of the two crucial model parameters, WEPP could adequately account for the water balance for the modeled experimental plot. For the study area, continuous corn with a conservation practice that delayed primary and secondary tillages produced low surface runoff and soil erosion, from both field observation and WEPP modeling. However, this mono-cultural practice may lead to accelerated soil-quality degradation. On the other hand, a fouryear-rotation, corn-wheat-alfalfa-alfalfa, was predicted to substantially reduce soil 0022-1694/$ -see front matter ª a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / j h y d r o l erosion and has potential to become a sustainable cropping system under the pedo-climatic settings of the study area. ª
- by Paola Pisa and +2
- •
- Hydrology
A study on pH and chemical composition of precipitation was carried out in two Italian sites, one urban (site 1) and one rural (site 2), located approximately 30 km far from Bologna, during a 3-year period. No significative site variation... more
A study on pH and chemical composition of precipitation was carried out in two Italian sites, one urban (site 1) and one rural (site 2), located approximately 30 km far from Bologna, during a 3-year period. No significative site variation was found. In both locations, bulk deposition pH ranged from slightly acid to slightly alkaline, despite the volume weighted mean concentration of acidic species, NO 3 − and SO 4 2− (67.4 and 118.4 μeq l −1 in site 1 and 88.7 and 103.8 μeq l −1 in site 2), that were similar to those of typical acidic rainfall region. This might be ascribed to the neutralization reaction of the Ca 2+ , attributed to the calcareous soil and the frequent dusty air mass intrusion from the Sahara. The pair correlation matrix and the analysis of the main components suggested also ammonium and other crustal elements as neutralization agents. The depositional rate of SO 4 2− and NO 3 − , chemical elements of agricultural interest, amounted to 38 and 28 and 32 and 35 kg ha −1 for site 1 and site 2, respectively. These supplies of nutrient were not negligible and had to be considered on cultivated lands. NH 4 + deposition rate on site 2 was 7 kg ha −1 , 23% over site 1, probably due to nitrogen fertilization in the fields around the monitoring station. In site 1, SO 4 2− presented a seasonal trend, indicating that its principal source was the residential heating. Results emphasized that the entity of the bulk deposition acidification is linked not only to the ions local emission sources (fossil fuel combustions, heating, and fertilizers) but also to the surrounding territory and the prevalent wind that transports through kilometers air masses which may contain acidic and alkaline species.
Agriculture has both direct and indirect effects on quality of surface water and is one of the key activities causing water quality degradation. Its environmental impact can be evaluated by the determination of indicators of the quality... more
Agriculture has both direct and indirect effects on quality of surface water and is one of the key activities causing water quality degradation. Its environmental impact can be evaluated by the determination of indicators of the quality of water bodies that collect drainage and runoff waters from agricultural watersheds. For this research, the water quality draining from three watersheds, totally or partially cultivated, all within the Po river valley (Italy), was determined, using chemical indicators (N-NO3 and N-NH4 concentration, N balance), trophic status (chlorophyll-a concentration) and benthic population indexes. Together, they should provide an overview of the water status, which is supposed to be strictly related to the land use and the management. Results show that the chemical parameters are well related to land use and farming management: intensive agricultural activity leads to high N-NO3 concentration in water and N surplus and vice versa. The chlorophyll-a concentration follows the same trend, being linked to nitrogen loads and land use. Not always there is accordance between chemical and biological indicators: no direct correspondence is evident between the N-NO3 concentration in waters and benthic community. Its presence and abundance seems to be mostly correlated with the geomorphology, hydrology, riparian strips, etc. of the habitat than to the land use. Only the integration of chemical and biological parameters allows a correct understanding of the state of health of water body and benthic communities.
- by Linda Pieri and +3
- •
The research was carried out for 7 years, 1998-2005, in a semi-agricultural watershed, called Centonara, set within a natural regional park and situated in the hills surrounding Bologna, northern Italy. This area is characterized by one... more
The research was carried out for 7 years, 1998-2005, in a semi-agricultural watershed, called Centonara, set within a natural regional park and situated in the hills surrounding Bologna, northern Italy. This area is characterized by one of the most interesting badlands complexes in Europe and represents one of the main points of naturalistic interest. The watershed is partially cultivated (about 30% of the total area) with arable crops, mostly cereals and alfalfa. To evaluate the impact of agricultural activity on the eco-sustainability of this area, the nitrogen (N) balance was computed. Although it is only an estimation of the potential environmental damage, the nitrogen balance is a useful indicator of the risk posed to the environment from excessive nitrogen and can be useful to understand the possible effects of a certain type of agricultural and environmental management and policy. The balance was calculated by computing the difference between all inputs and all outputs. The nitrogen balance of the watershed was found to be sustainable, with an annual nitrogen balance ranging between -2.3 and +4.4 kg ha -1 . Despite the limited presence of arable lands, the agricultural management played the main role in determining the sustainability of the watershed, strongly influencing both the principal N sources and sinks. In fact, major N inputs derived from inorganic fertilization (8.1-15.5 kg ha -1 yr -1 ) and biological fixation (8.3-14.3 kg ha -1 yr -1 ). On the other hand, plant removal constituted the most important output (17.7-25.6 kg ha -1 yr -1 ). N losses in the drainage water were limited (3.0-9.5 kg ha -1 yr -1 ) and the Centonara stream water was found to be unpolluted, with a nitrate concentration always below the EU limit for drinking water. The similar magnitude of total N inputs and outputs indicated that the crop management, especially the crop rotation and the N fertilization, in the Centonara watershed has reached a good level of ecological sustainability. Finally, the computation of the N fertilizer-use efficiency index resulted to be useful to identify which crop and which type of management (organic or conventional) were more suitable for the pedo-climatic condition of the studied area.
The study reports an integrated environmental quality monitoring of a 100km(2) area in central Italy mostly occupied by an underground station of methane storage, working since 1982. The nitrogen oxides, ozone and isoprene concentration... more
The study reports an integrated environmental quality monitoring of a 100km(2) area in central Italy mostly occupied by an underground station of methane storage, working since 1982. The nitrogen oxides, ozone and isoprene concentration detached with a network monitoring of passive filters were compared with the results of lichens biomonitoring. Data from the two monitorings were in accordance: there was an inversely correlation between lichen biodiversity index (IBL) and NOx (-0.96) and ozone (-0.80), and a positive correlation between IBL and isoprene (0.67). IBL indicated that the area ranged between medium naturalness and medium alteration status, values fully compatible with the medium-high level of eutrophication, caused by intensive agriculture. Only two areas were in high alteration status, due to their proximity to glass factories and to a quarries area. Despite almost thirty years of activity, the environment quality of the area around the station did not show signs of dec...
- by Linda Pieri and +2
- •
The development of Diglyphus isaea (Walker), a parasitoid of leafminers, was studied under laboratory conditions at four constant temperatures (15, 20, 25, and 30°C) on the hosts Liriomyza trifolii (Burgess) and Liriomyza huidobrensis... more
The development of Diglyphus isaea (Walker), a parasitoid of leafminers, was studied under laboratory conditions at four constant temperatures (15, 20, 25, and 30°C) on the hosts Liriomyza trifolii (Burgess) and Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). Parasitoid developmental time was found to be inversely related to temperature. At 15°C, D. isaea took about 28 days to complete its development on L. huidobrensis and about 27 days on L. trifolii. In comparison, at 20°C developmental time dropped to half on both species and the same happened from 20 to 30°C. At 25°C, parasitoid development was complete after about 10 days. At all tested temperatures and on both host species, the length of pupal stage of the parasitoid was slightly shorter than the egg + larva period. Linear regression and the Logan model were used to describe the relationship between developmental rate and temperature. For egg to adult development, female D. isaea required 161.8 degree-days (DD) above the theoretical threshold of 9.2°C on L. trifolii and 165.0 DD above 9.3°C on L. huidobrensis, and males required 151.4 DD above 9.5°C on L. trifolii and 157.4 DD above 9.3°C on L. huidobrensis. Optimum temperatures for total female and male development on L. trifolii were 33.3 and 32.3°C, and on L. huidobrensis 32.6 and 31.0°C, respectively. The effects of host, sex, and temperature on parasitoid size were studied. Significant sex-temperature, host-temperature, and host-sex-temperature interactions were found. The host species was found to affect female parasitoid size differently based on temperature.
- by Giovanni Bazzocchi and +1
- •
- Entomology
Classical biological control is generallyunderstood as an environmentally safe practiceof insect pest management. However, questionshave been raised about possible negativeeffects for native species. As part of a riskassessment study a... more
Classical biological control is generallyunderstood as an environmentally safe practiceof insect pest management. However, questionshave been raised about possible negativeeffects for native species. As part of a riskassessment study a semi-field trial was carriedout in northern Italy in order to compare theoverwintering of the native species Propylea quatuordecimpunctata (L.) and Adalia bipunctata (L.) (Coleoptera:Coccinellidae) with the exotic Harmoniaaxyridis (Pallas) (Coleoptera: Coccinellidae).All the experiments were carried out from April1998 to April 2001. Harmonia axyridis wasable to overwinter successfully in northernItaly. Fecundity, oviposition rate, longevityand rate of increase of overwintering femaleswere calculated and the phenology of the threespecies was studied. Harmonia axyridisoverwintering mortality (31.9%) was lower incomparison with mortality of native species(68.9% for P. quatuordecimpunctata and61.3% for A. bipunctata). As aconsequence, post-overwintering rate ofincrease of the exotic species was higher.Longevity of overwintered females was similaramong the species. Mean fecundity of H. axyridis (783.8 eggs per female) was slightlyhigher than A. bipunctata (720.2 eggs perfemale), and much higher than P. quatuordecimpunctata (193.7 eggs per female). H. axyridis and A. bipunctatacompleted four generations and P. quatuordecimpunctata three generations in a year. The results show that H. axyridisappears to posses a high potential for establishment in Italy.
Classical biological control is generally understood as an environmentally safe practice of insect pest management. However, questions have been raised about possible negative effects for native species. As part of a risk assessment study... more
Classical biological control is generally understood as an environmentally safe practice of insect pest management. However, questions have been raised about possible negative effects for native species. As part of a risk assessment study a semi-field trial was carried out in northern Italy in order to compare the overwintering of the native species Propylea quatuordecimpunctata (L.) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae) with the exotic Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). All the experiments were carried out from April 1998 to April 2001. Harmonia axyridis was able to overwinter successfully in northern Italy. Fecundity, oviposition rate, longevity and rate of increase of overwintering females were calculated and the phenology of the three species was studied. Harmonia axyridis overwintering mortality (31.9%) was lower in comparison with mortality of native species (68.9% for P. quatuordecimpunctata and 61.3% for A. bipunctata). As a consequence, post-overwintering rate of increase of the exotic species was higher. Longevity of overwintered females was similar among the species. Mean fecundity of H. axyridis (783.8 eggs per female) was slightly higher than A. bipunctata (720.2 eggs per female), and much higher than P. quatuordecimpunctata (193.7 eggs per female). H. axyridis and A. bipunctata completed four generations and P. quatuordecimpunctata three generations in a year. The results show that H. axyridis appears to posses a high potential for establishment in Italy.
Classical biological control is generally understood as an environmentally safe practice of insect pest management. However, questions have been raised about possible negative effects for native species. As part of a risk assessment study... more
Classical biological control is generally understood as an environmentally safe practice of insect pest management. However, questions have been raised about possible negative effects for native species. As part of a risk assessment study a semi-field trial was carried out in northern Italy in order to compare the overwintering of the native species Propylea quatuordecimpunctata (L.) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae) with the exotic Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). All the experiments were carried out from April 1998 to April 2001. Harmonia axyridis was able to overwinter successfully in northern Italy. Fecundity, oviposition rate, longevity and rate of increase of overwintering females were calculated and the phenology of the three species was studied. Harmonia axyridis overwintering mortality (31.9%) was lower in comparison with mortality of native species (68.9% for P. quatuordecimpunctata and 61.3% for A. bipunctata). As a consequence, post-overwintering rate of increase of the exotic species was higher. Longevity of overwintered females was similar among the species. Mean fecundity of H. axyridis (783.8 eggs per female) was slightly higher than A. bipunctata (720.2 eggs per female), and much higher than P. quatuordecimpunctata (193.7 eggs per female). H. axyridis and A. bipunctata completed four generations and P. quatuordecimpunctata three generations in a year. The results show that H. axyridis appears to posses a high potential for establishment in Italy.
Bt maize, genetically engineered to produce insecticidal Cry proteins from the bacterium Bacillus thuringiensis Berliner, is regarded as very taxon-specific, but concerns were raised about the possibility of unintended negative effects on... more
Bt maize, genetically engineered to produce insecticidal Cry proteins from the bacterium Bacillus thuringiensis Berliner, is regarded as very taxon-specific, but concerns were raised about the possibility of unintended negative effects on non-target organisms. Lady beetles (Coleoptera: Coccinellidae) could be exposed to Cry toxins through Bt maize pollen, as for many predatory coccinellids pollen is an important alternative food. Hedgerows in maize agroecosystems inside protected areas in Northern and Central Italy were sampled using sweep nets in spring and summer of 2011 and 2012. A total of 11 species were recorded, including the invasive Harmonia axyridis (Pallas) in Northern Italy. Through PCA, it was determined that each site has a different, recognizable and relatively stable coccinellid community structure. Continuous monitoring of ladybird assemblages thus might be useful to detect environmental alterations. In Northern Italy, maize flowering coincided with a high coccinell...
- by Salvatore Arpaia and +2
- •
Yield production in flowering crops depends on both nutrient availability and pollination, but their relative roles and potential interactions are poorly understood. We measured pollination benefits to yield in sunflower, combining a... more
Yield production in flowering crops depends on both nutrient availability and pollination, but their relative roles and potential interactions are poorly understood. We measured pollination benefits to yield in sunflower, combining a gradient in insect pollination (0, 25, 50, 100%) with a continuous gradient in nitrogen (N) fertilization (from 0 to 150 kg N ha −1 ) in an experiment under realistic soil field conditions. We found that pollination benefits to yield were maximized at intermediate levels of N availability, bolstering yield by approximately 25% compared with complete pollinator exclusion. Interestingly, we found little decrease in yield when insect visits were reduced by 50%, indicating that the incremental contribution of pollination by insects to yield is greater when the baseline pollination service provision is very low. Our findings provide strong evidence for interactive, nonlinear effects of pollination and resource availability on seed production. Our results sup...
This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and... more
This is the author manuscript accepted for publication and has undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as