TY - JOUR
T1 - Impact of urban sewage sludge on soil physico-chemical properties and phytotoxicity as influenced by soil texture and reuse conditions
AU - Hechmi, Sarra
AU - Hamdi, Helmi
AU - Mokni-Tlili, Sonia
AU - Ghorbel, Manel
AU - Khelil, Mohamed Naceur
AU - Zoghlami, Inès Rahma
AU - Benzarti, Saoussen
AU - Jellali, Salah
AU - Hassen, Abdennaceur
AU - Jedidi, Naceur
N1 - Funding Information:
This project was supported by a national grant from the Ministry of Higher Education and Scientific Research of Tunisia. The authors thank the Center of Material Science at Borj Cedria Technopark, Tunisia, for inductively coupled plasma analysis.
Funding Information:
This project was supported by a national grant from the Ministry of Higher Education and Scientific Research of Tunisia. The authors thank the Center of Material Science at Borj Cedria Technopark, Tunisia, for inductively coupled plasma analysis.
Publisher Copyright:
© 2020 The Authors. Journal of Environmental Quality © 2020 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
PY - 2020/7/1
Y1 - 2020/7/1
N2 - Urban sewage sludge (USS) is increasingly applied to agricultural soils, but mixed results have been reported because of variations in reuse conditions. Most field trials have been conducted in cropping systems, which conceal intrinsic soil responses to sludge amendments due to the rhizosphere effect and farming practices. Therefore, the current field study highlights long-term changes in bare soil properties in strict relationship with soil texture and USS dose. Two agricultural soils (loamy sand [LS] and sandy [S]) were amended annually with increasing sludge rates up to 120 t ha−1 yr−1 for 5 yr under unvegetated conditions. Outcomes showed a USS dose-dependent variation of all studied parameters in topsoil samples. Soil salinization was the most significant risk related to excessive USS doses. Total dissolved salts (TDS) in saturated paste extracts reached the highest concentrations of 37.2 and 43.1 g L−1 in S soil and LS soil, respectively, treated with 120 t USS ha−1 yr−1. This was also reflected by electrical conductivity of the saturated paste extract (ECe) exceeding 4,000 µS cm−1 in both treatments. As observed for TDS, fertility indicators and bioavailable metals varied with soil texture due to the greater retention capacity of LS soil owing to higher fine fraction content. Soil phytotoxicity was estimated by the seed germination index (GI) calculated for lettuce, alfalfa, oat, and durum wheat. The GI was species dependent, indicating different degrees of sensitivity or tolerance to increasing USS rates. Lettuce germination was significantly affected by changes in soil conditions showing negative correlations with ECe and soluble metals. In contrast, treatment with USS enhanced the GI of wheat, reflecting higher salinity tolerance and a positive effect of sludge on abiotic conditions that control germination in soil. Therefore, the choice of adapted plant species is the key factor for successful cropping trials in sludge-amended soils.
AB - Urban sewage sludge (USS) is increasingly applied to agricultural soils, but mixed results have been reported because of variations in reuse conditions. Most field trials have been conducted in cropping systems, which conceal intrinsic soil responses to sludge amendments due to the rhizosphere effect and farming practices. Therefore, the current field study highlights long-term changes in bare soil properties in strict relationship with soil texture and USS dose. Two agricultural soils (loamy sand [LS] and sandy [S]) were amended annually with increasing sludge rates up to 120 t ha−1 yr−1 for 5 yr under unvegetated conditions. Outcomes showed a USS dose-dependent variation of all studied parameters in topsoil samples. Soil salinization was the most significant risk related to excessive USS doses. Total dissolved salts (TDS) in saturated paste extracts reached the highest concentrations of 37.2 and 43.1 g L−1 in S soil and LS soil, respectively, treated with 120 t USS ha−1 yr−1. This was also reflected by electrical conductivity of the saturated paste extract (ECe) exceeding 4,000 µS cm−1 in both treatments. As observed for TDS, fertility indicators and bioavailable metals varied with soil texture due to the greater retention capacity of LS soil owing to higher fine fraction content. Soil phytotoxicity was estimated by the seed germination index (GI) calculated for lettuce, alfalfa, oat, and durum wheat. The GI was species dependent, indicating different degrees of sensitivity or tolerance to increasing USS rates. Lettuce germination was significantly affected by changes in soil conditions showing negative correlations with ECe and soluble metals. In contrast, treatment with USS enhanced the GI of wheat, reflecting higher salinity tolerance and a positive effect of sludge on abiotic conditions that control germination in soil. Therefore, the choice of adapted plant species is the key factor for successful cropping trials in sludge-amended soils.
UR - http://www.scopus.com/inward/record.url?scp=85086256553&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85086256553&partnerID=8YFLogxK
U2 - 10.1002/jeq2.20093
DO - 10.1002/jeq2.20093
M3 - Article
C2 - 33016480
AN - SCOPUS:85086256553
SN - 0047-2425
VL - 49
SP - 973
EP - 986
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 4
ER -