Sewage Sludge Application Enhances the Growth of Corchorus olitorius Plants and Provides a Sustainable Practice for Nutrient Recirculation in Agricultural Soils

Abstract

The current study aimed at evaluating the effects of different sewage sludge (SS) amendment rates as biofertilizers on growth of Corchorus olitorius plants and soil properties, with an emphasis on heavy metal (HM) allocation in plant parts and postharvest soil. Then, the soil was supplemented with various SS rates (0, 10, 20, 30, and 40 g kg −1). The effects of these SS amendment rates on different growth parameters of Corchorus olitorius and soil properties were investigated. The SS amendment rate of 20 g kg −1 triggered the highest growth rates of Corchorus plants. Micronutrient HMs, including Co, Cu, Mn, and Ni, increased in the shoots of plants grown in soils amended with 20 g kg −1 , but with levels sufficient for normal plant growth and below the phytotoxic limits. The sludge application significantly increased the content of organic matter in postharvest soil from 1.38 to 4.83% at the amendment rate of 20 g kg −1. Furthermore, our data showed that the quantities of the estimated HMs remaining in postharvest soils were below (Cu, Fe, Mn, Mo, Zn, and Pb) or within (Co, Ni, Cd, and Cr) the maximum permissible concentrations in agricultural soils at all of the SS amendment rates. Taken together, our findings suggest that soil application of SS can provide a sustainable safe practice for SS disposal and improve plant growth, while exerting no environmental threats provided there is no accumulation of HMs to toxic levels in shoots of the grown plants or in the amended soils.

Long-Term Effect of Heavy Metal–Polluted Wastewater Irrigation on Physiological and Ecological Parameters of Salicornia europaea L.

“…Long-term irrigation with sewage effluent was shown to increase the amount and availability of heavy metals in soils (Liu et al 2005). Soil fertility and plant growth can be enhanced with properly managed wastewater irrigation through increasing levels of soil organic matter and plant nutrients which may eliminate the need for commercial fertilizers in cropland (Mojid et al 2019;Eid 2019). To alleviate the problems of land salinization and the contamination of soils with heavy metals, a group of plants has been identified such as halophytes, salt-tolerant plants, and heavy metal hyperaccumulators which can extract heavy metals from the soil (Moray et al 2015).…”

Uptake prediction of ten heavy metals by Corchorus olitorius L. cultivated in soil mixed with sewage sludge

“…Soil–SS combination that support s the growth of C. olitorius in the current study was alkaline (pH range is 7.2–8.4). Soil alkalinity decreases the mobility of HMs (Eid, Alrumman, El‐Bebany, et al, 2018, 2019; Eid, Alrumman, et al, 2017; Eid, El‐Bebany, et al, 2017; Eid, Hussain, et al, 2019; Zeng et al, 2011). Furthermore, high soil pH is known to increase the uptake of various HMs and in turn decrease its solubility in soil solutions (Chaudri et al, 2007).…”

“…In addition, the concentrations of all of the monitored HMs concentrations in C. olitorius shoots (except Fe) did not reach the critical levels proposed by Kabata‐Pendias (2011) (see Table 2). Although the amendment of agricultural soils using SS may be practical for some crops such as spinach, cucumbers, faba beans, wheat, and C. olitorius (Eid, Alrumman, El‐Bebany, et al, 2018, 2019; Eid, Alrumman, et al, 2017; Eid, El‐Bebany, et al, 2017; Eid, Hussain, et al, 2019), the consistent checking of the HMs levels in agricultural products is recommended to avoid their accumulation in the food chain.…”

“…SS is produced, as an organic by‐product after treating the municipal and industrial drainage water (Eid & Shaltout, 2016). Industries contribute in raising the toxic levels of HMs in SS, that may have lethal effects (e.g., As, Cd, Hg, Pb) on food chain, but some reports indicated that the amendment of agricultural lands with SS has significant positive influences on soil quality and plant nutrients (Antonious, Kochhar, & Coolong, 2012; Eid, Alrumman, El‐Bebany, et al, 2018, 2019; Eid, Alrumman, et al, 2017; Eid, El‐Bebany, et al, 2017; Eid, Hussain, et al, 2019; Kumar, Chopra, & Srivastava, 2016; Tamoutsidis, Papadopoulos, Tokatlidis, Zotis, & Mavropoulos, 2002; Waqas, Khan, Qing, Reid, & Chao, 2014). Zeng et al (2011) suggested that the reduction of the toxic impacts of HMs and their translocation to food chains needs impact assessment of different soil parameters on their accessibility and uptake by plants.…”

“…Since 2016, our team has started to publish a series of papers about the impact of varied amendment rates of SS on the plant growth and yield in addition to the accumulation of HMs in some economic plants (Eid, Alrumman, El‐Bebany, et al, 2018, 2019; Eid, Alrumman, et al, 2017; Eid, El‐Bebany, et al, 2017; Eid, Hussain, et al, 2019). According to the authors’ knowledge, no regression equations can be found in the literature for the uptake of HMs by C. olitorius grown in soil amended with SS.…”