Land Application of Sewage Sludge: Physiological and Biochemical Response of the Rio Grande Tomato

Abstract

Treated wastewater produces sewage sludge as a by-product that may have beneficial implications on agricultural practices. The effects of sludge amendments on growth, morphological and biochemical characteristics of the agro-industrial Tomato cultivar Rio Grande were observed. A pot culture experiment was carried out during 4 months (16 February 2019 to 18 June 2019), at an experimental green house in the locality of Salah Soufi, Guelma, north-eastern Algeria. There were significant differences between soil and sewage sludge samples. Total nitrogen (20.58 mg/kg) was more available in sewage sludge than in soil (N = 2.09 ± 0.3 mg/kg). In contrast, sludge contained less phosphorus and organic matter than soil. The observation of the morphological characteristics of the plants showed significant variations between the treatments. The germination rates for treated soils decreased significantly to reach 50%, compared to the control. Growth patterns (dry and fresh weight of leaves and roots) changed significantly (P <0.05) between the treatments. Chlorophyll contents of plants in treated soils were more than twice as high as those of the control, but started decreasing at 75% amendment rates.