Aims Improvement in nutrient efficiency of recycled fertiliser products represents a crucial step for sustainable agriculture. In this context, ash from biomass combustion belongs to the materials of ...interest. Methods Novel strain of potential plant growth-promoting bacterium (Paenibacillus mucilaginosus ABi13) was tested for its ability to increase the plant availability of nutrients from wood ash (WA) in P-deficient soil-plant systems. Maize plants were grown in soil microcosms in semi-natural conditions, enabling rhizospheric- and bulk-soil solution analysis with special emphasis on low-molecular-mass organic acids (LMMOA). Results Wood ash, as a sole fertiliser, increased biomass yield and improved nutritional status of maize plants. Concomitantly, application of WA led to lower root exudation rates of malate and isocitrate likely due to improved P status of plants. P. mucilaginosus ABi13 was inefficient in mobilising P from plain, acidic soil, but increased P solubility in ash-amended soil. However, P. mucilaginosus ABi13 consequently decreased NO3− concentrations in soil solution and induced N deficiency in maize, which led to decreased biomass yield and LMMOA exudation rates. Conclusions This study demonstrated the importance of plant nutritional status on the final outcome of PGPR inoculation and contributes to our understanding of interactions between introduced PGPR, soil microbiome and plants.
Display omitted
•Tested fungal strains enhance uptake of P from wood ash by maize.•Both strains inhibit dehydrogenase activity and reduce microbial P.•P sorption capacity of soil inhibits the ...performance of P-solubilisers.
Effective recycling of phosphorus (P) remains a critical issue in sustainable agriculture. Wood ash represents valuable soil amendment and potential source of P for agriculture, but its solubility and subsequent P-fertilisation efficiency is extremely low. This study tested fungal inoculants (Penicillium sp. PK112 and Trichoderma harzianum OMG08) applied alone and in combination with wood ash on P-limiting acidic soil to determine if they can improve P-nutrition in maize. Wood ash alone did not have any significant P-fertilising effect. Application of both inoculants, when combined with wood ash, led to significant increment of plant-available P content in soil, increased P uptake by maize plants and consequently to higher production of maize shoot biomass. Both inoculants suppressed overall microbial activity in soil as determined by the activity of dehydrogenase, alkaline phosphatase and microbial P content. Only T. harzianum led to higher activity of soil acid phosphatase. This study demonstrated that tested strains may be co-applied with wood ash to improve its P-fertilisation efficiency. The positive influence of inoculants on P availability was mainly due to stronger acidification of rhizosphere and decreased content of microbial P. However, both effects seemed to be hindered by the P sorption capacity of the soil in the case of inoculation without wood ash. Such findings may lead to development of novel formulations of recycled fertiliser products and boost nutrient recycling in agriculture.
The aim of this study was to evaluate metals (Cd, Cu, Pb and Zn) sorption behavior after biochar application into a metal-contaminated soil. Additionally, two different types of biochar originating ...from the same organic material (contaminated and uncontaminated) at different application rates (1% and 2% w/w) were evaluated as a novelty of the experiment. Batch sorption/desorption experiments were established to compare the sorption behavior of metals originating from single- and multi-element solutions. Zinc as one of the main contaminants in the studied soil was easily desorbed in the presence of Cu, Pb and to a lesser extent by Cd. This desorption was reduced after biochar application. The obtained results proved the different sorption behavior of metals in the single-metal solution compared to the multi-metal ones due to competition effect. Moreover, during multi-element sorption, Zn was significantly desorbed. The applied biochar enhanced Cu and Pb sorption and no changes were observed when contaminated and uncontaminated biochar was used. Furthermore, the application rate (1% and 2% w/w) had no effect as well. In summary, it is needed to point out that the applied rates of biochars were insufficient for metal immobilization in such contaminated soils.
Soil from Trhové Dušníky (Příbram, Czech Republic) is characterized by its high polymetallic accumulations in Pb–Ag–Zn due to mining and smelting activities. In previous studies performed in our ...research group, we have evaluated the potential use of amendments that would reduce the mobility and availability of metals such as Hg. We have observed that the application of digestate and fly ash in metal-polluted soil has an impact in immobilizing these metals. However, until now we have lacked information about the effect of these amendments on soil microbial functionality and communities. The multi-contaminated soil was used to grow wheat in a pot experiment to evaluate the impact of digestate and fly ash application in soil microbial communities. Soil samples were collected after 30 and 60 days of treatment. The digestate application improved chemical attributes such as the content in total organic carbon (TOC), water soluble carbon (WSOC), total soluble carbon (C), total soluble nitrogen (N), and inorganic N forms (NO3−) as consequence of high content in C and N which is contained in digestate. Likewise, microbial activity was greatly enhanced by digestate application, as was physiological diversity. Bacterial and fungal communities were increased, and the microbial biomass was highly enhanced. These effects were evident after 30 and 60 days of treatment. In contrast, fly ash did not have a remarkable effect when compared to digestate, but soil microbial biomass was positively affected as a consequence of macro- and micro-nutrient sources applied by the addition of fly ash. This study indicates that digestate can be used successfully in the remediation of metal-contaminated soil.
•Digestate improved the chemical attributes of soil.•Soil functionality, diversity and structure were positively affected by digestate.•Digestate and fly ash stimulated an increase in soil microbial biomass.•Digestate can be used in the reclamation of metal-contaminated soil.
Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous ...species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116
mg
Cd
kg
−1 and 4680
mg
Zn
kg
−1 in leaves of
Salix caprea. Annual variation of Cd and Zn concentrations in leaves of
Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (
aqua regia) or labile (1
M NH
4NO
3 extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots.
Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680
mg
Zn
kg
−1 and 116
mg
Cd
kg
−1 in their leaves.
The effect of nitrogen, phosphorus and potassium (NPK) fertilizer with different nitrogen forms on N, P, K use, uptake and growth of potted chrysanthemum plants during three vegetation phases was ...observed in two - years experiment. In the experiment, NPK fertilizer with slow soluble nutrients with different nitrogen forms: ureaform, (IBDU) isobutyledenediurea and melamin, was used. At control treatment the identical fertilizer was applied but the nitrogen was in ammonia and urea forms as usually used in horticulture. The experiment clearly showed the positive effect of NPK fertilizer containing half nitrogen amount in ureaform, on growth and plant nutrient uptake. This effect of nitrogen ureaform was confirmed by both the highest uptake of N, P, K and the highest yield of biomass. The NPK fertilizer with half nitrogen content in ureaform ensured optimal nutrient release according chrysanthemum nutrient requirement.
PDF
