N-Fertilizer (Urea) Enhances the Phytoextraction of Cadmium through Solanum nigrum L.

Abstract

Heavy metal contamination is currently a major environmental concern, as most agricultural land is being polluted from municipal discharge. Among various other pollutants, cadmium (Cd), one of the most harmful heavy metals, enters into the food chain through the irrigation of crops with an industrial effluent. In the present study, a pot experiment was designed to assess the effect of different nitrogen (N)-fertilizer forms in the phytoremediation of Cd through Solanum nigrum L. Two types of N fertilizers (NH4NO3 and urea) were applied to the soil in different ratios (0:0, 100:0, 0:100, and 50:50 of NH4NO3 and urea, individually) along with different Cd levels (0, 25, and 50 mg kg−1). The plants were harvested 70 days after sowing the seeds in pots. Cadmium contamination significantly inhibited the growth of leaves and roots of S. nigrum plants. Cadmium contamination also induced oxidative stress; however, the application of N-fertilizers increased the plant biomass by inhibiting oxidative stress and enhancing antioxidants’ enzymatic activities. The greatest plant growth was observed in the urea-treated plants compared with the NH4NO3-treated plants. In addition, urea-fed plants also accumulated higher Cd concentrations than NH4NO3-fed plants. It is concluded that urea is helpful for better growth of S. nigrum under Cd stress. Thus, an optimum concentration of N-fertilizers might be effective in the phytoremediation of heavy metals through S. nigrum.

Biochar-based compost: a bibliometric and visualization analysis

“…An increase in the number of publications from 2011 to 2021, with an anticipated increase in the number in 2022, shows that the research on biochar compost is still growing and is being explored by researchers from different fields of study, and countries or regions. The increasing attention can be explained by the effect of steady and continuous application of inorganic fertilizers on plant accumulation of heavy metals, decreasing grain quality and nutrition of crops [ 104 ; 105 ], including water, air, and soil pollution through the accumulation of toxic chemicals in water bodies, and physical soil degradation [ 106 ]. Contrary to the long-term application of inorganic fertilizers, biochar-based compost has proven to be an effective organic fertilizer for soil heavy metal immobilization.…”

Phosphorus Fertilizers Enhance the Phytoextraction of Cadmium through Solanum nigrum L.

“…Total and available P concentrations were 2.20 mg kg −1 and Zn, Cu, Cd total and available concentrations were 0.81 mg kg −1 ; 0.34 mg kg −1 and 0.09 mg kg −1 , respectively. Complete physicochemical characteristics of the soil used in this experiment are described before (Arosha et al, 2020) [ 22 ]. This experiment had been carried out in botanical garden of Government College University Faisalabad (Faisalabad, Pakistan; 31°25′0″ N 73°5′28″ E) during (April–June) in 2019.…”

Agricultural Strategies to Reduce Cadmium Accumulation in Crops for Food Safety

“…NO 3 supplementation might increase organic acid production and promote Cd translocation via xylem through organic acid complex forms [142]. Several other studies also revealed that N fertilizer in the form of NH 4 + in soil increased Cd uptake via rhizospheric acidification and root cell proton excretion in sunflower and S. nigrum plants [138,143]. Moreover, Xie, et al [144] found that supplementation with NO 3 − promotes Cd and Zn phytoextraction by Noccaea (Thlaspi) caerulescens.…”