Effect of irrigation with treated wastewater on bermudagrass (Cynodon dactylon (L.) Pers.) production and soil characteristics and estimation of plant nutritional input

PLoS One. 2022 Jul 15;17(7):e0271481. doi: 10.1371/journal.pone.0271481. eCollection 2022.

Abstract

In recent years, climate change has greatly affected rainfall and air temperature levels leading to a reduction in water resources in Southern Europe. This fact has emphasized the need to focus on the use of non-conventional water resources for agricultural irrigation. The reuse of treated wastewater (TWW) can represent a sustainable solution, reducing the consumption of freshwater (FW) and the need for mineral fertilisers. The main aim of this study was to assess, in a three-year period, the effects of TWW irrigation compared to FW on the biomass production of bermudagrass [Cynodon dactylon (L.) Pers.] plants and soil characteristics and to estimate the nutritional input provided by TWW irrigation. TWW was obtained by a constructed wetland system (CWs) which was used to treat urban wastewater. The system had a total surface area of 100 m2. An experimental field of bermudagrass was set up close to the system in a Sicilian location (Italy), using a split-plot design for a two-factor experiment with three replications. Results highlighted a high organic pollutant removal [five days biochemical oxygen demand (BOD5): 61%, chemical oxygen demand (COD): 65%] and a good efficiency in nutrients [total nitrogen (TN): 50%, total phosphorus (TP): 42%] of the CWs. Plants irrigated with TWW showed higher dry aboveground dry-weight (1259.3 kg ha-1) than those irrigated with FW (942.2 kg ha-1), on average. TWW irrigation approximately allowed a saving of 50.0 kg TN ha-1 year-1, 24.0 kg TP ha-1 year-1 and 29.0 kg K ha-1 year-1 on average with respect to commonly used N-P-K fertilisation programme for bermudagrass in the Mediterranean region. Soil salinity increased significantly (p ≤ 0.01) over the years and was detected to be higher in TWW-irrigated plots (+6.34%) in comparison with FW-irrigated plots. Our findings demonstrate that medium-term TWW irrigation increases the biomass production of bermudagrass turf and contributes to save significant amounts of nutrients, providing a series of agronomic and environmental benefits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agricultural Irrigation
  • Cynodon
  • Nitrogen / analysis
  • Phosphorus
  • Soil
  • Soil Pollutants* / analysis
  • Wastewater*

Substances

  • Soil
  • Soil Pollutants
  • Waste Water
  • Phosphorus
  • Nitrogen

Grants and funding

This study was funded by the Assessorato Regionale dell’Agricoltura, dello Sviluppo Rurale e della Pesca Mediterranea, Regione Sicilia (in English: Ministry of Agriculture, Rural Development and Mediterranean Fisheries of Sicilian Region) under project title "Contributo Enti di cui all’art. 128 della LR 11/2010 e SS.MM.ED I. - Anno 2021 – Fitodepurazione (Grant No. D73C21000060005). The funder did not play any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.