In in contesto di carenza idrica e di inquinamento delle acque superficiali causato dalle attività agricole, devono essere identificate nuove pratiche di gestione delle risorse idriche che rispondano a queste problematiche e possano essere utilizzate in diversi ambienti. Il bacino idrografico della Laguna di Venezia (nell'Italia nord-orientale) è un'area sensibile all'inquinamento delle acque superficiali. La prevalenza di terreni pianeggianti e la presenza di una falda freatica superficiale, tuttavia, suggeriscono condizioni idonee per la realizzazione di due pratiche di gestione idrica per la riduzione dei carichi di N e P provenienti dalle aree agricole: il drenaggio controllato (controlled drainage: CD) e le wetland artificiali a flusso superficiale (surface flow constructed wetlands: SFCWs). Il monitoraggio di lungo periodo delle performance di queste pratiche è necessario per fornire risultati di validità generale, che non siano condizionati dalla variabilità meteorologica annuale. Questo lavoro valuta le performance di un sistema di CD e di SFCW in un esperimento di lungo periodo. Il CD è stato monitorato durante i periodi 1995-2002 e 2006-2013, in termini di bilancio idrico e di resa delle colture, e dal 2007 al 2013 anche per le perdite di N e P. La SFCW è stata monitorata dal 2007 al 2013 per la riduzione dei carichi di N e P. Il CD ha permesso di ridurre i deflussi idrici del 69% e ha determinato un aumento complessivo della resa di granella di mais del 26,3%, e della resa di mais da insilato del 4,0%. Le perdite di NO3-N e PO4-P nelle acque superficiali sono state ridotte rispettivamente del 92% e del 65%. La SFCW ha mostrato tassi di rimozione annui apparenti dell'83% e del 79% rispettivamente per NO3-N e N totale, e del 48% e del 67% rispettivamente per PO4-P e P totale. Sia il CD che la SFCW si sono rivelati efficaci nel ridurre i carichi inquinanti di N e P, ed il CD ha anche contribuito ad aumentare la resa delle colture attraverso il risparmio idrico. Per questi motivi, l'applicazione di queste due pratiche di gestione idrica è da prendersi in considerazione in questo ambiente.
In the context of increasing water scarcity and surface water pollution caused by agricultural activities, new water management practices that tackle these issues and that could be used in different environments should be identified. The Venice Lagoon drainage basin (in north-eastern Italy) is a sensitive area to surface water pollution. The prevalence of flat lands and the presence of shallow phreatic groundwaters, however, create suitable conditions for the implementation of two water management practices that can reduce N and P loads coming from agricultural fields: controlled drainage (CD) and surface flow constructed wetlands (SFCWs). Long-term monitoring of the performances of these practices is required to provide sound results that are not contingent on annual weather variability. This work evaluates the performances of a CD and SFCW system in a long-term experiment. CD was monitored during the periods 1995-2002 and 2006-2013 for water balance and crop yield, and from 2007 to 2013 for N and P losses. The SFCW was monitored from 2007 to 2013 for N and P removal loads. CD permitted to reduce water outflows of 69%, and provided an overall increase in maize grain yield of 26.3% and in silage maize yield of 4.0%. NO3-N and PO4-P losses to surface waters were reduced by 92% and 65%, respectively. The SFCW showed annual apparent removal rates of 83% and 79% respectively for NO3-N and total N, and of 48% and 67% respectively for PO4-P and total P. Both CD and SFCW proved effective in reducing N and P loads, and CD helped increasing crop yield through water saving. For these reasons, the application of these two water management practices is advisable in this environment.
Evaluation of long-term water management strategies for saving water and reducing nitrogen and phosphorus losses from agricultural fields: controlled drainage and surface flow constructed wetland case studies in Venice Lagoon drainage basin / Tolomio, Massimo. - (2018 Sep 29).
Evaluation of long-term water management strategies for saving water and reducing nitrogen and phosphorus losses from agricultural fields: controlled drainage and surface flow constructed wetland case studies in Venice Lagoon drainage basin
Tolomio, Massimo
2018
Abstract
In the context of increasing water scarcity and surface water pollution caused by agricultural activities, new water management practices that tackle these issues and that could be used in different environments should be identified. The Venice Lagoon drainage basin (in north-eastern Italy) is a sensitive area to surface water pollution. The prevalence of flat lands and the presence of shallow phreatic groundwaters, however, create suitable conditions for the implementation of two water management practices that can reduce N and P loads coming from agricultural fields: controlled drainage (CD) and surface flow constructed wetlands (SFCWs). Long-term monitoring of the performances of these practices is required to provide sound results that are not contingent on annual weather variability. This work evaluates the performances of a CD and SFCW system in a long-term experiment. CD was monitored during the periods 1995-2002 and 2006-2013 for water balance and crop yield, and from 2007 to 2013 for N and P losses. The SFCW was monitored from 2007 to 2013 for N and P removal loads. CD permitted to reduce water outflows of 69%, and provided an overall increase in maize grain yield of 26.3% and in silage maize yield of 4.0%. NO3-N and PO4-P losses to surface waters were reduced by 92% and 65%, respectively. The SFCW showed annual apparent removal rates of 83% and 79% respectively for NO3-N and total N, and of 48% and 67% respectively for PO4-P and total P. Both CD and SFCW proved effective in reducing N and P loads, and CD helped increasing crop yield through water saving. For these reasons, the application of these two water management practices is advisable in this environment.File | Dimensione | Formato | |
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