Impact of earthworm activity on the chemical fertility of irrigated soil with urban effluents

The reuse of urban effluents to irrigate the soils of peri-urban grasslands in the vicinity of the town of Setif (northeastern Algeria) is an old and widespread practice. In this context, the present study was conducted to evaluate the effect of the irrigation with urban effluents on the biological and chemical behavior of soils. Effluents analysis showed significant organic and particulate pollution, the latter contributed to earthworm abundance and increased the richness of irrigated soils with nutrients. The analysis of turricules revealed the role of earthworms through the activity of bioturbation in the increase of the rate of organic matter as well as in the bioavailability of the nutrients of the irrigated soils. In space, permanent vegetation cover has played an important role as a biofilter. This was confirmed by the inter-site differences recorded through the measured variables particularly organic ones.Keywords: Natural grasslands, urban effluents, earthworm activity, turricles, organic matte

DOES EARTHWORMS DENSITY REALLY MODIFY SOIL'S HYDRODYNAMIC PROPERTIES IN IRRIGATED SYSTEMS WITH RECYCLED WATER?

<p>Our study has the general objective to understand the impact of the valuation of treated water on earthworm abundance and total porosity of the soil and the effect of the interaction between these two physical-biological components of the hydrological functioning of soils. It was carried out on the meadows soils of the valley of Wadi Bousselam.</p><p>Although the treated water has high organic and particulate filler, it improved the earthworm abundance, total porosity and hydraulic conductivity of the soil.</p

Long-term effects of wastewater reuse on hydro physicals characteristics of grassland grown soil in semi-arid Algeria

The raw and treated wastewaters are often evacuated downstream of settlements and widely reused in pre-urban agricultural irrigation. Our study highlights the impact of wastewaters on the soil hydro-physical properties as well as biological activity. Our study was conducted in eastern part of Algeria, on long-term (>60 years) wastewater irrigated grassland to determine the biological component and hydrodynamic soil behavior under these practices. Effects of three wastewater types (raw urban, treated and agricultural effluents) on soil were studied and water was characterized both physically and chemically. Assessment of the effects involved soil porosity, soil hydraulic conductivity and earthworms abundance. The results revealed that waters contain high concentrations of organics (BOD 5&COD) and suspended solids (SS). Hydro-physical properties and biological activity showed that irrigation with raw urban wastewater enhances soil earthworm density, porosity and higher water transfer via hydraulic conductivity. Biological activity resulted in ideal pore architecture for materials and solutes transfer, induced a variety of micro morphological transformations in relation to the abundance of earthworm communities mostly endogeic and anecic. (C) 2019 The Authors. Published by Elsevier B.V