title: Effects of waste water irrigation on soil properties and soil fauna of spinach fields in a West African urban vegetable production system.
abstract: The usage of inadequately processed industrial waste water (WW) can lead to strong soil alkalinity and soil salinization of agricultural fields with negative consequences on soil properties and biota. Gypsum as a soil amendment to saline-sodic soils is widely used in agricultural fields to improve their soil physical, chemical and hence biological properties. This study aimed at analysing the effects of intensive WW irrigation on the structure and composition of soil-dwelling arthropods on spinach fields (Spinacia oleracea L.) in a West African urban vegetable production system. We used gypsum as a soil amendment with the potential to alleviate soil chemical stress resulting in a potentially positive impact on soil arthropods. A total of 32 plots were established that showed a gradient in soil pH ranging from slight to strong soil alkalinity and that were irrigated with WW (n = 12) or clean water (CW; n = 20), including eight plots into which gypsum was incorporated. Our study revealed a high tolerance of soil-dwelling arthropods for alkaline soils, but spinach fields with increased soil electrical conductivity (EC) showed a reduced abundance of Hymenoptera, Diptera and Auchenorrhyncha. Arthropod abundance was positively related to a dense spinach cover that in turn was not affected by WW irrigation or soil properties. Gypsum application reduced soil pH but increased soil EC. WW irrigation and related soil pH affected arthropod composition in the investigated spinach fields which may lead to negative effects on agronomical important arthropod groups such as pollinators and predators.
authors.affiliation: Universität Kassel, Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics (OPATS), Steinstrasse 19, D-37213 Witzenhausen, Germany. Electronic address: stenchly@uni-kassel.de.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Stenchly
authors.affiliation: Universität Kassel, Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics (OPATS), Steinstrasse 19, D-37213 Witzenhausen, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Dao
authors.affiliation: Institut de l'Environnement et de Recherches Agricoles (INERA), Burkina Faso; Université Ouaga I Professeur Joseph Ki-Zerbo, Centre Universitaire Polytechnique de Dédougou (CUPD), 03 BP 7021 Ouagadougou 03, Burkina Faso.
authors.forename: Désiré Jean-Pascal
authors.initials: DJ
authors.lastname: Lompo
authors.affiliation: Universität Kassel, Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics (OPATS), Steinstrasse 19, D-37213 Witzenhausen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Buerkert
mesh_terms: D057914:Agricultural Irrigation; D000818:Animals; D001181:Arthropods / Q000187:drug effects*; D002050:Burkina Faso; D002133:Calcium Sulfate; D002947:Cities; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000009:adverse effects* / Q000032:analysis; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*; D018724:Spinacia oleracea / Q000187:drug effects*; D014675:Vegetables / Q000187:drug effects; D062065:Wastewater / Q000737:chemistry / Q000633:toxicity*; D014867:Water / Q000032:analysis
chemical_list: D002133:Calcium Sulfate; D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants; D062065:Wastewater; D014867:Water
keywords: Burkina Faso; Ecological entomology; Gypsum; Sewage; Soil pH; Urban agriculture