Ecological strategy for soil contaminated with mercury

Aims The paper presents results from plot experiments aimed at the development of an ecological strategy for soil contaminated with mercury. Meadow grass (Poa pratensis) was tested on mercury contaminated soil in a former chlor-alkali plant (CAP) in southern Poland for its phytoremediation potential. Methods The stabilisation potential of the plants was investigated on plots without additives and after the addition of granular sulphur. Biomass production, uptake and distribution of mercury by plants, as well as leachates and rhizosphere microorganisms were investigated, along with the growth and vitality of plants during one growing season. Results The analysed plants grew easily on mercury contaminated soil, accumulating lower amounts of mercury, especially in the roots, from soil with additive of granular sulphur (0.5 % w/w) and sustained a rich microbial population in the rhizosphere. After amendment application the reduction of Hg evaporation was observed. Conclusions The obtained results demonstrate the potential of using Poa pratensis and sulphur for remediation of mercury contaminated soil and reduction of the Hg evaporation from soil. In the presented study, methods of Hg reduction on “hot spots” were proposed, with a special focus on environmental protection. This approach provides a simple remediation tool for large areas heavily contaminated with mercury

Hormesis in Plants: The Role of Oxidative Stress, Auxins and Photosynthesis in Corn Treated with Cd or Pb

Hormesis, which describes the stimulatory effect of low doses of toxic substances on growth, is a well-known phenomenon in the plant and animal kingdoms. However, the mechanisms that are involved in this phenomenon are still poorly understood. We performed preliminary studies on corn coleoptile sections, which showed a positive correlation between the stimulation of growth by Cd or Pb and an increase in the auxin and H2O2 content in the coleoptile sections. Subsequently, we grew corn seedlings in hydroponic culture and tested a wide range of Cd or Pb concentrations in order to determine hormetic growth stimulation. In these seedlings the gas exchange and the chlorophyll a fluorescence, as well as the content of chlorophyll, flavonol, auxin and hydrogen peroxide, were measured. We found that during the hormetic stimulation of growth, the response of the photosynthetic apparatus to Cd and Pb differed significantly. While the application of Cd mostly caused a decrease in various photosynthetic parameters, the application of Pb stimulated some of them. Nevertheless, we discovered that the common features of the hormetic stimulation of shoot growth by heavy metals are an increase in the auxin and flavonol content and the maintenance of hydrogen peroxide at the same level as the control plants

Influence of short-term macronutrient deprivation in maize on photosynthetic characteristics, transpiration and pigment content

The aim of the research was to compare the impact of short-term deprivation of selected macronutrients (Ca, K, Mg and P) on the photosynthetic characteristics, transpiration and pigment content in maize. The strongest inhibition of photosynthesis was caused by a deprivation of Mg, which was visible as a decrease in the photosynthetic and transpiration rates, stomatal conductance, photosystem II (PSII) performance, chlorophyll and flavonol content with a simultaneously increased content of anthocyanins. In the K-deprived plants, a decrease in the photosynthetic rate was observed. However, the transpiration rate and stomatal conductance did not differ significantly compared with the control. In the K-deprived plants, a decrease in chlorophyll and an increase in the anthocyanin content were also observed. We showed that Ca starvation resulted in a decrease in the photosynthetic and transpiration rates, stomatal conductance and PSII performance, while the pigment content was not significantly different compared with the control. In the case of P-deprived plants, we observed a decrease in the photosynthetic and transpiration rates. Interestingly, the inhibition of stomatal conductance was the strongest in the P-deprived plants compared with all of the investigated elements. However, the performance of PSII was not significantly affected by P starvation compared with the control. Our results present for the first time a comprehensive analysis of the effect of short-term macronutrient deprivation on photosynthesis and transpiration in maize plants

How autochthonous microorganisms influence physiological status of Zea mays L. cultivated on heavy metal contaminated soils?

Funding information This work was supported by the Polish Ministry of Science and Higher Education (Institute for Ecology of Industrial Areas statutory funds).Peer reviewedPublisher PD

Perennial biomass cropping and use: Shaping the policy ecosystem in European countries

Demand for sustainably produced biomass is expected to increase with the need to provide renewable commodities, improve resource security and reduce greenhouse gas emissions in line with COP26 commitments. Studies have demonstrated additional environmental benefits of using perennial biomass crops (PBCs), when produced appropriately, as a feedstock for the growing bioeconomy, including utilisation for bioenergy (with or without carbon capture and storage). PBCs can potentially contribute to Common Agricultural Policy (CAP) (2023–27) objectives provided they are carefully integrated into farming systems and landscapes. Despite significant research and development (R&D) investment over decades in herbaceous and coppiced woody PBCs, deployment has largely stagnated due to social, economic and policy uncertainties. This paper identifies the challenges in creating policies that are acceptable to all actors. Development will need to be informed by measurement, reporting and verification (MRV) of greenhouse gas emissions reductions and other environmental, economic and social metrics. It discusses interlinked issues that must be considered in the expansion of PBC production: (i) available land; (ii) yield potential; (iii) integration into farming systems; (iv) R&D requirements; (v) utilisation options; and (vi) market systems and the socio-economic environment. It makes policy recommendations that would enable greater PBC deployment: (1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; (2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low-carbon bioenergy and bioproducts; (3) support innovation in biomass utilisation value chains; and (4) continue long-term, strategic R&D and education for positive environmental, economic and social sustainability impacts

Building the Policy Ecosystem in Europe for Cultivation and Use of Perennial Biomass Crops

Perennial biomass crops (PBCs) can potentially contribute to all ten Common Agricultural Policy (2023-27) objectives and up to eleven of the seventeen UN Sustainable Development Goals. This paper discusses interlinked issues that must be considered in the expansion of PBC production: i) available land; ii) yield potential; iii) integration into farming systems; iv) research and development requirements; v) utilisation options; and vi) market systems and the socio-economic environment. The challenge to create development pathways that are acceptable for all actors, relies on measurement, reporting and verification of greenhouse gas emissions reduction in combination with other environmental, economic and social aspects. This paper makes the following policy recommendations to enable greater PBC deployment: 1) incentivise farmers and land managers through specific policy measures, including carbon pricing, to allocate their less productive and less profitable land for uses which deliver demonstrable greenhouse gas reductions; 2) enable greenhouse gas mitigation markets to develop and offer secure contracts for commercial developers of verifiable low carbon bioenergy and bio-products; 3) support innovation in biomass utilisation value chains; and 4) continue long-term, strategic research and development and education for positive environmental, economic and social sustainability impacts. © 2023 ETA-Florence Renewable Energies

Ecological strategy for soil contaminated with mercury

Aims The paper presents results from plot experiments aimed at the development of an ecological strategy for soil contaminated with mercury. Meadow grass (Poa pratensis) was tested on mercury contaminated soil in a former chlor-alkali plant (CAP) in southern Poland for its phytoremediation potential. Methods The stabilisation potential of the plants was investigated on plots without additives and after the addition of granular sulphur. Biomass production, uptake and distribution of mercury by plants, as well as leachates and rhizosphere microorganisms were investigated, along with the growth and vitality of plants during one growing season. Results The analysed plants grew easily on mercury contaminated soil, accumulating lower amounts of mercury, especially in the roots, from soil with additive of granular sulphur (0.5 % w/w) and sustained a rich microbial population in the rhizosphere. After amendment application the reduction of Hg evaporation was observed. Conclusions The obtained results demonstrate the potential of using Poa pratensis and sulphur for remediation of mercury contaminated soil and reduction of the Hg evaporation from soil. In the presented study, methods of Hg reduction on “hot spots” were proposed, with a special focus on environmental protection. This approach provides a simple remediation tool for large areas heavily contaminated with mercury

Diminishing the risk on lead and zinc ore regions by subtle modulation of soil properties

The negative effect of non-ferrous metal emission in Upper Silesian Industrial Region (Poland) on the quality of soil is continuously present. It poses a serious threat on living organisms and is an important factor influencing the level of metal load introduced to human organism. Easy way for diminishing the metal uptake by plants is the amendment application to the soil. Presented study was conducted to evaluate the effect of the introduction of sewage sludge and fly ashes from power station into the medium contaminated soil. Heavy metals in soil were stabilized with a mixture of sewage sludge and fly ashes from the local wastewater treatment plant and power plant. Previously the mixture was tested in terms of the probability of its ecotoxicological impact on plant growth and development. Even low doses of the mixture addition to the contaminated soil caused a observable reduction of lead, cadmium and zinc in leaves of grasses. Soil additives also increased the soil pH

Diminishing the risk on lead and zinc ore regions by subtle modulation of soil properties

The negative effect of non-ferrous metal emission in Upper Silesian Industrial Region (Poland) on the quality of soil is continuously present. It poses a serious threat on living organisms and is an important factor influencing the level of metal load introduced to human organism. Easy way for diminishing the metal uptake by plants is the amendment application to the soil. Presented study was conducted to evaluate the effect of the introduction of sewage sludge and fly ashes from power station into the medium contaminated soil. Heavy metals in soil were stabilized with a mixture of sewage sludge and fly ashes from the local wastewater treatment plant and power plant. Previously the mixture was tested in terms of the probability of its ecotoxicological impact on plant growth and development. Even low doses of the mixture addition to the contaminated soil caused a observable reduction of lead, cadmium and zinc in leaves of grasses. Soil additives also increased the soil pH