Nitrogen and phosphorus fertilization increases the uptake of soil heavy metal pollutants by plant community

Abstract

Background: Soil heavy metal pollution is widespread around the world. Heavy metal pollutants are easily absorbed by plants and enriched in food chain, which may harm human health, cause the loss of plant, animal and microbial diversity. Plants can generally absorb soil heavy metal pollutants. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. However, the amount of heavy metals absorbed could be less, and the biomass would be reduced under heavy metal pollution. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can increase the resistance of plants to adversity and promote the growth of plants of heavy metal polluted soils.Methods: We designed a comparative greenhouse experiment with heavy metal contaminated soils, and set up four treatments: CK treatment (soil without fertilizer), N treatment (soil with N addition), P treatment (soil with P addition), and N+P treatment (soil with N and P addition).Results: Our results showed that plant aboveground biomass were 231.17%, 14.84%, 269.86% greater than CK treatment, respectively. N and P fertilizer stimulated plants to allocate more biomass to the aboveground parts. In addition, N treatments significantly reduced the content of Cd in aboveground and belowground biomass of plants (P < 0.05); P fertilizer significantly decreased the content of Cu in aboveground biomass (P < 0.05). N+P treatments significantly reduced the content of Cd, Cu in aboveground and belowground biomass of plants (P < 0.05). Meanwhile, N and N+P significantly increased the accumulation (mg/m2) of Cd, Cu, and Pb in plant aboveground biomass (P < 0.05). N and N+P fertilizer increased aboveground-belowground heavy metals accumulation ratio (P < 0.05), promoting plants to uptake more heavy metal pollution out of soil.Conclusions: N and P fertilizer increased the accumulation of heavy metals in aboveground of the natural plant community and accelerated the absorption of heavy metals by plants, and N fertilizer had a better effect. Our results provide an inexpensive method for remediation of heavy metal pollution in low economic value soils, such as contaminated farmland, abandoned land and mine tailings, etc.

Addressing Heavy Metal Pollution in Nigeria: Evaluating Policies, Assessing Impacts, and Enhancing Remediation Strategies

“…Prioritizing the development and implementation of these techniques offers an opportunity to reduce environmental impact and promote sustainable practices. Policy proposals also play a crucial role in enhancing remediation efforts (Tang et al, 2021). Differentiated national pollution reduction policies should be implemented for cadmium, mercury, lead, and other heavy metals to improve water pollution control measures (Zlati et al, 2022).…”

“…This information provides valuable insights for designing targeted and efficient remediation plans. Integrated treatment options have been proposed to remove and recover heavy metals from polluted soils, water, and sediments (Selvi et al, 2019;Tang et al, 2021). These methods include thermal treatment, adsorption, chlorination, chemical extraction, ion-exchange, membrane separation, electrokinetics, bioleaching, and others.…”