Impact of environmental pollution on peri-urban or proximity crops. Case of study: the Baix Llobregat Agricultural Park

Abstract

Peri-urban or proximity agriculture provides numerous advantages for horticulture, mainly associated with the short distance between the crop production area and the final market, leading to products of improved organoleptic and nutritive properties. Likewise, peri-urban agriculture reduces the carbon footprint associated with the transportation of orchard products between the production and consumption zones. Furthermore, the peri-urban areas have access to reclaimed waters from wastewater treatment plants of neighbouring cities, ensuring their availability throughout the productive cycle. The surrounding infrastructures (namely airports, harbours and highways), however, can increase the air pollution associated with wet and/or dry deposition (organic or inorganic) and gas phase contaminants (O3, SOx, NOx) which can lead to abiotic stress for the crops, decreasing their yield. On the other hand, reclaimed wastewater and biosolids contain a high concentration of nutrients and organic matter that is clearly beneficial to crops, but they can also contain chemical pollutants (metals and organic micropollutants) and microbiological pathogens that can be a potential hazard if they are taken up by crops. In this paper, some of the findings of a study conducted at the Baix Llobregat Agricultural Park (PABL) (Barcelona, Catalonia), where the irrigation water has different physical-chemical properties and a variable concentration of pollutants, are presented. Concentrations of trace elements in soil such Mo, Ni, Pb and As exceeded the standards for agricultural soil but most crops grown in the area are compliant (except for Pb). With respect to emerging pollutants, an anticonvulsive drug (carbamazepine and its 9,10-epoxide) was detected in crops, which is consistent with the indirect water reuse. Fungicides used for crop production together with plasticizers released from irrigation tubing were detected in the drip-irrigated crops. Nevertheless, no effects on agricultural productivity or on physiological plant parameters (lipid, sugar and chlorophyll content) were observed.

Keywords: peri-urban agriculture, irrigation water quality, soil pollution, air pollution, agricultural productivity, Baix Llobregat Agricultural Park.