Modeling Soil Nitrate Accumulation and Leaching in Conventional and Conservation Agriculture Cropping Systems

Nitrate is a major groundwater inorganic contaminant that is mainly due to fertilizer leaching. Compost amendment can increase soils’ organic substances and thus promote denitrification in intensively cultivated soils. In this study, two agricultural plots located in the Padana plain (Ferrara, Italy) were monitored and modeled for a period of 2.7 years. One plot was initially amended with 30 t/ha of compost, not tilled, and amended with standard fertilization practices, while the other one was run with standard fertilization and tillage practices. Monitoring was performed continuously via soil water probes (matric potential) and discontinuously via auger core profiles (major nitrogen species) before and after each cropping season. A HYDRUS-1D numerical model was calibrated and validated versus observed matric potential and nitrate, ammonium, and bromide (used as tracers). Model performance was judged satisfactory and the results provided insights on water and nitrogen balances for the two different agricultural practices tested here. While water balance and retention time in the vadose zone were similar in the two plots, nitrate leaching was less pronounced in the plot amended with compost due to a higher denitrification rate. This study provides clear evidence that compost addition and no-tillage (conservation agriculture) can diminish nitrate leaching to groundwater, with respect to standard agricultural practices

In Search for the Missing Nitrogen: Closing the Budget to Assess the Role of Denitrification in Agricultural Watersheds

Although representing a paramount mechanism against nitrogen excess in agricultural landscapes, soil denitrification is still a largely unknown term in nitrogen balances at the watershed scale. In the present work, a comprehensive investigation of nitrogen sources and sinks in agricultural soils and waters was performed with the aim of gaining insights into the relevance of soil denitrification in a highly farmed sub-basin of the Po River delta (Northern Italy). Agricultural statistics, water quality datasets, and results of laboratory experiments targeting nitrogen fluxes in soils were combined to set up a detailed nitrogen budget along the terrestrial–freshwater continuum. The soil nitrogen budget was not closed, with inputs exceeding outputs by 72 kg N·ha−1·year−1, highlighting a potential high risk of nitrate contamination. However, extensive monitoring showed a general scarcity of mineral nitrogen forms in both shallow aquifers and soils. The present study confirmed the importance of denitrification, representing ~37% of the total nitrogen inputs, as the leading process of nitrate removal in heavily fertilized fine-texture soils prone to waterlogged conditions

Is Bioenergy Truly Sustainable When Land-Use-Change (LUC) Emissions Are Accounted for? The Case-Study of Biogas from Agricultural Biomass in Emilia-Romagna Region, Italy

Bioenergies are considered sustainable alternatives to fossil energy sources in the European Union (EU) renewable energy targets for 2030. However, their performances in terms of greenhouse gases (GHG) savings may be affected by indirect emissions related to the required land-use-change (LUC) that should be taken into account when modelling their sustainability. The European Renewable Energy Directive (RED) introduced a number of GHG emission criteria, in comparison with fossil fuels, that bioenergy deriving from agricultural biomasses must comply with. The Emilia-Romagna region (North-Eastern Italy), the second largest Italian biogas producer, has recently issued its Regional Energy Plan (REP), which set an ambitious increase of about 40% of the current installed electric power from biogas up to 2030. The aim of this study is to assess the sustainability of Emilia-Romagna REP accounting for the required indirect land-use-change (ILUC), due to the bioenergy crop expansion, potentially needed to reach the targets. Based on regional data available on biogas production, the amount of land used for maize silage to be destined to biogas production (as a model agricultural feedstock) has been calculated for the actual state-of-the art and towards 2030 scenarios provided by the REP. Starting from average GHG emissions associated with biogas production from 100% maize silage of 35 gCO(2) eq/MJ, a further contribution of 8-18.5 gCO(2) eq/MJ due to LUC has been found. Our findings indicate that it is difficult to assess the global GHG savings from the bioenergy targets fixed by regional energy plans when LUC effects are considered. Careful analysis is necessary in each case to avoid creating negative impacts

Life Cycle Assessment of Oyster Farming in the Po Delta, Northern Italy

Oysters represent an important portion of the world’s total aquaculture production. In recent years, in Italy, oyster farming has progressively increased its role in the economic growth of the aquaculture sector and still has great potential for growth. As in any other production, oyster farming generates environmental impacts over an oyster’s life cycle, due to material, energy, fuel, and water use. The aim of this work was to carry out a cradle-to-gate life cycle assessment (LCA) of 1 kg of fresh oysters of commercial size produced in the Po delta area, northern Italy. Two scenarios were considered. The current scenario provides for oyster seed purchasing from France and transport to Italy, whereas the alternative scenario includes in situ seed production in order to realize a complete local and traceable supply chain. Eco-indicator® 99-H and ReCiPe® midpoint (H) v.1.12 were used to perform the impact assessments. The overall impacts of the two scenarios were very similar and indicated that the main hotspots were the fattening and prefattening phases of farming, which were common in both scenarios. Focusing the analysis on the first stages, transport from France had a greater impact than did local seed production, emphasizing the importance of a short supply chain in aquaculture production

Sustainability of Mussel (Mytilus Galloprovincialis) Farming in the Po River Delta, Northern Italy, Based on a Life Cycle Assessment Approach

Molluscan shellfish aquaculture is considered a “green” industry because of the limited presence of chemicals and risk of pathogens during farming in licensed areas, which provide a safe, nutritive and healthy food source. Moreover, the environmental impact of their production is lower than all other fish animal per unit of protein. In particular, mussels’ production was the first organized mollusk aquaculture in Europe and is now one of the most extended. Italy is the second main European producer of mussels. Taking into account the relevance of the sector, Italian Mediterranean mussel (Mytilus galloprovincialis) aquaculture has been considered for a life cycle assessment (LCA), from a cradle-to-gate perspective. The mussel farms were located in the northern Adriatic Sea, close to the Po River Delta, a region traditionally vocated to bivalve aquaculture. Results have shown that the growing and harvesting phases are the most critical life cycle stages (“hotspots”) due to the production and use of boats, and the great quantity of non-recyclable high-density polyethylene (HDPE) socks used during the yearly productive cycle. Several improvement potentials have been identified and estimated by means of a sensitivity analysis. Furthermore, regarding the principal exporting countries to Italy (Spain and Chile), the transport factors in an overall sustainability assessment have been considered, in order to compare the local and global mussels supply chain

Life Cycle Based Evaluation of Environmental and Economic Impacts of Agricultural Productions in the Mediterranean Area

In recent years, there has been an increasing interest in Life Cycle Assessment (LCA) applied to estimate the cradle-to-grave environmental impact of agricultural products or processes. Furthermore, including in the analysis an economic evaluation, from the perspective of an integrated life cycle approach, appears nowadays as a fundamental improvement. In particular, Life Cycle Costing (LCC), is a method that could integrate financial data and cost information with metrics of life cycle approaches. In this study, LCA in conjunction with LCC methods were used, with the aim to evaluate the main cost drivers—environmental and economic—of five widely diffused and market-valued agricultural productions (organic tomato and pear, integrated wheat, apple and chicory) and to combine the results in order to understand the long-term externalities impacts of agricultural productions. Data obtained in local assessment show a wide margin of improvement of resources management at farms level in the short-term, but also allow for the investigation of future effects of environmental impacts not expressed in product price on the market. Reaching a real sustainable model for agriculture could be a value added approach firstly for farmers, but also for all the people who live in rural areas or use agricultural products

Non-market ecosystem services of agricultural aand and priorities towards a more sustainable agriculture in Italy

Ecosystems provide a range of services, commonly called Ecosystem Services (ESs), which are of funda-mental importance to human well-being, health, livelihoods, and survival. One of the largest and most productiveecosystems is agricultural land. Agro-Ecosystems provide a range of services directly linked to the market (e.g. food and raw materials production) but also many others of high ecological value, which have an indirect economical contribution in the GDP (non-market ESs). These non-market services are not usually taken into account in the development of agricultural management strategies while their contribution is reduced due to non-sustainable agricultural practices. The aim of the study is to assess the potential economic contribution of the non-market services at national, regional, and provincial level in Italy and to propose a simplified index-based method for setting priorities at different scales of administration units for the implementation of sustainable agricultural practices (SAPs). The results of the study showed that the potential non-market value of agro-ecosystem services (AESs) in Italy can reach ~46.2 billion USD$2007. This estimate shows that non-market AESs can play an important role in the national GDP if SAPs are followed. Finally, a priority ranking scheme for the implementation of SAPs was proposed at regional and provincial level which can be a valuable decision support tool for promoting sustainable agriculture policies

Introducing Life Cycle Assessment in costs and benefits analysis of vegetation management in drainage canals of lowland agricultural landscapes

Nitrogen overload could provoke several effects on water quality in freshwater and coastal environment, in terms of eutrophication and groundwater nitrate contamination. Those effects can have a severe impact on ecosystem function and human health. In order to reduce nitrogen excess, constructed wetlands are usually recognized as a solution, but in recent years interest has been raised on the role of ditches and canals network in efficient nitrogen abatement. In this study, we investigated the environmental and economical sustainability of natural nitrogen removal capacity of both canals vegetation and microbial communities in the Burana-Volano-Navigabile (BVN) basin, located in the Po valley, the largest Italian hydrographic system. Based on life cycle assessment (LCA) approach and cost-benefits analysis, the effectiveness of two different vegetation management scenarios, which differ for the mowing management, on N abatement in the canal network of the case-study area has been compared. The results highlighted that postponing the mowing of aquatic vegetation to the end of vegetative season would contribute to buffer about 90% of the N load conveyed by the canal network during the irrigation period and would reduce of an order of magnitude the potential costs due to environmental damages

How does invasion degree shape alpha and beta diversity of freshwater fish at a regional scale?

FFreshwater ecosystems appear more vulnerable to biodiversity loss due to several anthropogenic disturbances and freshwater fish are particularly vulnerable to these impacts. We aimed to (1) identify the contribution of land use, spatial variables, and invasion degree in determining freshwater fish alpha (i.e., species richness) and beta (i.e., local contributions to beta diversity, LCBD) diversity, evaluating also the relationship between invasion degree and nestedness ((Formula presented.) nes) and turnover ((Formula presented.) sim) components of beta diversity. (2) Investigate the relationship between alpha diversity and LCBD, under the hypothesis that alpha diversity and LCBD correlate negatively and (3) investigate the relationship between species contributions to beta diversity (SCBD) and species occurrence, hypothesizing that non-native species show a lower contribution to beta diversity. The linear mixed models and the partition of R2 retained the invasion degree as the most important variables explaining alpha and beta diversity, having a positive relationship with both diversity components. Furthermore, land use related to human impacts had a positive influence on alpha diversity, whereas it showed a negative effect on LCBD. Regression model further showed that invasion degree related positively with (Formula presented.) sim, but negatively with (Formula presented.) nes, suggesting that non-native species were involved in the replacement of native species in the fish community. Alpha diversity and LCBD showed a weak positive correlation, meaning that sites with low species richness have higher LCBD. SCBD scaled positively with species occurrence highlighting that rarer species contribute less to SCBD. Finally, native and exotic species contributed similarly to beta diversity. These results suggest that invasion degree plays a central role in shaping alpha and beta diversity in stream fish, more than land use features reflecting habitat alteration or other geospatial variables. Furthermore, it is important to evaluate separately the native and the non-native components of biotic communities to identify linkages between invasion dynamics and biodiversity loss.Peer reviewe

Sensitivity to selected contaminants in a biological early warning system using 'Anodonta woodiana' (Mollusca)

Several early warning systems for the monitoring of water quality are based on the assessment of valve opening/closing in bivalves. Tests were conducted to assess the sensitivity of the mussel Anodonta woodiana , installed on the Mosselmonitor, to seven contaminants and evaluate the usefulness of these sensors for detecting pollution events in the Po River (Italy). Mussels were exposed for 30 min to increasing concentrations of chromium (range 0.01–5 mg/L); arsenic (range 0.05–2.5 mg/L); sodium dodecyl sulphate SDS (range 0.25–50 mg/L); phenol (range 0.1–100 mg/L); oxadiazon (range 0.001–5 mg/L); trichloroethylene (range 0.01–100 mg/L); and crude oil (range 0.5–50 mg/L). Treatment with the highest concentration of SDS elicited two types of alarm response. In a second set of tests, the bivalves were exposed for 6 h to a selected concentration of each chemical. Only SDS led to a dramatic alteration of valve opening, resulting in alarms. This system would have limited applications for monitoring drinking water influent. Keywords: bioindication, mussels, valve movement, toxicity test, toxic substance