Beyond the WFD in Lowland Soils: Zeolife, a Project to Minimize Livestock Effluents

The Water Framework Directive (WFD) was applied since 2006 in Ferrara Province (Italy). Notwithstanding elevate nitrate and ammonium (NH4 +) concentrations are still present in surface and groundwater of reclaimed areas, respectively. To diminish nitrogen export from agricultural lands an EU project “ZeoLIFE” was funded in 2011, currently testing an integrated zeolitite cycle to reduce the amount of fertilizers spread in the fields. Natural Kzeolitite (chabasite zeolitite) is mixed with swine manure in a prototype tank, where it takes NH4 + by cation exchange. The NH4 +-charged zeolitite was added to experimental plots, where it will slowly release nutrients only upon plant root request. Control plots cultivated in traditional way and plots with untreated natural zeolitite will also be monitored for two years of cultivation. In this paper the results of the monitoring activities on the control plots cultivated with maize are described. The high ammonium concentrations in shallow groundwater (15±15 mg/l) found over the first year of the project confirmed that the WFD application did not allow to reach the NH4 + admissible levels. This is also due to the presence of peaty layers that contribute to geogenic nitrogen export via mineralization of organic nitrogen. The application of natural zeolitite should improve groundwater and surface water quality, thanks to the reduction of chemical and organic fertilizers in agriculture. Despite of this amelioration, the geogenic background values may persist in deep soil horizons and shallow groundwater. These values should be taken into account during the implementation of the WFD.