Plant Biomass Accumulation Research Articles

Effect of In Vitro Pretreatment with Ag-Containing Amino Acid Nanofibers on Biometrics and Antioxidant Activity in Drought-Stressed Ex Vitro-Adapted Stevia rebaudiana Bertoni

Biotechnological methods prevent the destruction of natural populations of medicinal plants due to climate change and developing agriculture. This study evaluates the effects of in vitro pretreatment with two types of silver-containing amino acid nanofibers (NF-1%Ag and NF1-Ag salt) on the drought tolerance of ex vitro soil-adapted Steviia rebaudiana Bertoni. The duration of the drought was five days. The data suggested that the pretreatment with the studied nanofibers during plant propagation enhanced the plant tolerance to drought stress manifested in a smaller decrease in plant biomass accumulation and a smaller increase in sugar content. The pretreatment with the two tested nanoparticles of well-watered plants increased the leaf fresh biomass accumulation of the ex vitro-adapted S. rebaudiana compared to the untreated WW control plants. The highest values were reported at 10 mg L−1 NF1-Ag salt. Five days of drought led to a decrease in the leaf fresh biomass compared to the WW plants, with the recorded lowest reduction again at 10 mg L−1 NF1-Ag salt. These observations correlate with antioxidant activity improvement. The results show that adding 10 mg L−1 NF1-Ag salt to the MS medium led to higher ex vitro-adapted S. rebaudiana resistance to water deficit than 100 mg L−1. This paper discusses the impact of the selected nanofibers on parameters characterizing plant growth and antioxidant activity of drought-stressed ex vitro-adapted Stevia rebaudiana plants.

Partially Substituting Photosynthetic Photon Flux Density with Far-red Photons Differentially Alters Biomass Accumulation and Photochemical Efficiency of Greenhouse Lettuce

Adding far-red (FR) photons to a constant photosynthetic photon flux density (PPFD) alters photosynthesis, leaf morphology, and biomass accumulation of horticultural plants. However, the influences of partially substituting PPFD with FR photons under the same extended PPFD (ePPFD) on the growth of greenhouse lettuce (Lactuca sativa L.) is still unknown. In this study, loose-leaf lettuce (‘Dasusheng’) grown in a greenhouse in the fall was implemented using six supplementary light treatments including white plus red (WR) LEDs with substitutive FR photon flux density at 0, 10, 30, 50, 70, and 90 µmol·m−2·s−1 under the same ePPFD (WR139, WR129+FR10, WR109+FR30, WR89+FR50, WR69+FR70, and WR49+FR90, respectively). Lettuce grown with natural light only was designated as NL. The results indicated that supplementary light led to lower plant height, thicker leaves, higher biomass accumulation, higher vitamin C content, higher starch content, and higher total soluble sugar content in lettuce compared with those of lettuce grown under NL. Lettuce grown under WR139 resulted in a 40.0% decrease in plant height, 66.8% increase in leaf thickness, and 34.1% increase in shoot fresh weight compared with those of lettuce grown under NL. No significant differences were observed in leaf width, specific leaf area, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight, soil plant analysis development value, apparent quantum yield, soluble protein content, and light use efficiency of lettuce among the WR139, WR129+FR10, and WR109+FR30 treatments. Furthermore, decreased trends were observed in the biomass accumulation and maximum net photosynthetic rate of lettuce with the increased substituted FR photon flux density. However, an opposite trend was found in the maximum photochemical quantum yield. In conclusion, partially substituting PPFD with FR photons at 10 to 30 μmol·m−2·s−1 had similar effects on the biomass accumulation and nutritional quality of greenhouse lettuce. The FR photons should be applied with the consideration of photon flux density because the results also demonstrated negative effects of excess substituted FR photons for PPFD.

Grazing exclusion promotes soil organic carbon accumulation in Tibetan grasslands with lower temperatures

BackgroundGrazing exclusion is a practical approach to restore vegetation in degraded grasslands and enhance soil organic carbon (SOC) sequestration. However, the dynamics and drivers of SOC in grasslands after grazing exclusion have not been well documented, especially in ecosystems with cold climates.MethodsHere, we established 14 paired treatments (grazing exclusion vs. free-grazing) along a 600-km transect in the northeastern zone of the Qinghai-Tibet Plateau. After six years, we analyzed vegetation biomass dynamics and measured the soil physicochemical properties and organic C concentration across three depths (0–10, 10–20, and 20–30 cm).ResultsGrazing exclusion significantly increased above- and belowground biomass (139.85% and 43.30%, respectively), pH (1.38%), total phosphorus (3.29%), nitrate nitrogen (18.03%), and ammonium nitrogen (17.81%), but significantly decreased soil bulk density (2.43%) and clay content (10.49%), particularly in 0–30 cm. Specifically, SOC concentrations positively responded to grazing exclusion (0–10 cm) in 9 of the 14 sites evaluated. The effects of grazing exclusion on SOC concentrations were significantly higher in areas with a mean annual temperature (MAT) below 0 °C compared to those in sites with a high MAT (> 0 °C). The SOC concentrations significantly correlated with the mean annual precipitation (MAP) in both treatments, but these correlations diminished with increasing soil depth. Ridge regression analysis showed that soil chemical properties (e.g., total nitrogen and phosphorus) positively influenced SOC accumulation, while MAT negatively influenced it after grazing exclusion. Path analysis further revealed that MAT indirectly regulated SOC dynamics via soil chemical properties.ConclusionsOur study highlights that grazing exclusion results in an asynchronous SOC and plant biomass accumulation and may be more beneficial for SOC sequestration in Qinghai-Tibet Plateau grasslands with lower temperatures. Also, humid climates promote SOC concentration in alpine grasslands. These results could help develop management practices and policies that promote sustainable grassland management.

Exploring the Relationship Between Biochar Pore Structure and Microbial Community Composition in Promoting Tobacco Growth

The potential benefits of biochar, a carbon-rich substance derived from biomass, for enhancing agricultural yield and soil health have drawn increasing interest. Nevertheless, owing to the lack of specialized studies, the role of its poly-spatial structure in the success of fostering plant growth remains unclear. This study aimed to assess the effects of various biochar pore shapes on tobacco growth and the underlying microbiological processes. Three pyrolysis temperatures (250 °C, 400 °C, and 550 °C) were used to produce biochar from tobacco stems, resulting in different pore structures (T3 > T2 > T1). We then used BET-specific surface area (BET), t.Plot micropore specific surface area (t.Plot), mesopore specific surface area (MSSA), specific pore volume (SPV), average pore size (AP), and mesopore pore volume (MPV) measurements to evaluate the effects of these biochars on tobacco growth and biomass accumulation, and microbial analyses were performed to investigate the underlying mechanisms. When applied to plants, biochar increased their growth compared to untreated controls. The most notable improvement in tobacco growth was observed in the biochar produced at 400 °C (T3), which possessed the largest and most advantageous pore structure among all treatments. Further studies demonstrated that biochars with greater specific surface areas (BET, t.Plot, and MSSA) positively altered the abundance of key microbial taxa (e.g., Stenotrophobacter, Ensifer, Claroideoglomus) and community composition, thereby encouraging plant development and biomass accumulation. Conversely, greater pore volumes (SPV, AP, and MPV) inhibited microbial activity and significantly affected growth and biomass accumulation. Structural equation modeling further demonstrated that the pore structure of biochar greatly affected plant growth by changing the relative abundance and community composition of soil microbes. Maximizing the benefits of biochar in stimulating plant growth and improving soil microbial communities depends on optimizing the material’s pore structure, particularly by increasing the specific surface area. These findings will help expand the use of biochar in sustainable agriculture.

Manipulating the light spectrum to increase the biomass production, physiological plasticity and nutritional quality of Eruca sativa L

The extensive development in light-emitting diodes (LEDs) in recent years provides an opportunity to positively influence plant growth and biomass accumulation and to optimize biochemical composition and nutritional quality. This study aimed to assess how different light spectra affect the growth, photosynthesis and biochemical properties of Eruca sativa. Therefore two LED lighting modes - red:blue (RB, 1:1) and red:green:blue (RGB, 2:1:2) were compared to the conventional white light fluorescent tubes (WL). Plant biomass, photosynthetic performance, several antioxidants, polyamines and nitrates contents were analyzed across different treatments. The plant growth was affected by the light quality - the presence of green light in the spectrum resulted in smaller plants and leaves, and correspondingly less biomass. RB spectral mode enhanced the total antioxidant and guaiacol peroxidase activity, pigments, flavonoids, polyphenols, ascorbate and polyamines contents. This effect under RB was combined with better leaf development compared to RGB and less nitrate in the leaves among all treatments. The RB light generated modifications in polyamines, which are interrelated with the nitrate content, further induce important metabolite and antioxidant changes. Both RB and RGB enhanced photosynthesis. The afterglow thermoluminescence band varied according to leaves development, being higher in RB and WL as a consequence of their faster growth. The RB light spectrum was found to be the most efficient for promoting the growth, biochemical composition, and overall quality of Eruca sativa compared to RGB and WL. These findings suggest that RB LEDs can be an effective tool for improving crop production in controlled environments.

Neural network cognitive analysis of accumulation metals by marigold

The article presents the results of studies to assess the effect of humic acids, taken at a concentration of 250 ppm, on the process of induced phytoextraction of heavy metals from soils selected near Norilsk. Phytoxtraction was carried out by different types of marigold plants: Tagetes patula and Tagetes erecta. The studies were carried out in greenhouse conditions under controlled spectral illumination (light culture). The duration of the experiment was 21 days. A short vegetation period was chosen based on the conditions of a short summer period typical for this region, where it is more rational to keep records of the systemic removal of toxicants from contaminated soils by several cycles of their sowing/cutting per season, already at the juvenile phase of ontogenesis. For elemental analysis, the method of atomic emission spectrometry with inductively coupled plasma was used. To assess the level of efficiency of metal accumulation, the authors developed and used the original computing neural network CompNN, which allows calculating the cognitive significance index (CSI) based on empirical data on the accumulation of toxicants, both in shoots and roots of plants. The results of the study showed that the introduction of an organic additive in the form of humic acids into the soil led to inhibition of the growth of the above-ground part of T. patula. As for T. erecta, the rate of accumulation of green plant biomass did not change when humic acids were added. The decrease in the biomass of shoots of T. patula plants is explained by an increase in the accumulation of metals in them by an average of 91.6% for the variants. The content of metals in the shoots of T. erecta under the influence of humic acids, on the contrary, decreased by 17.3% on average. A similar result was observed in relation to the root zone: the trend of change in the fixation of metals for both plant species here was 40.8 and 10.8%, respectively. Calculation of CSI indices also showed that the addition of humic acids in T. patula increases the intensity of metal accumulation from the soil in its biomass in all variants, while in T. erecta, on the contrary, it decreases. The performed cluster analysis demonstrated the fixation of metals in the main buffer zone of plants, and also made it possible to isolate nickel into a separate homogeneous series. With regard to the distribution of this element in the shoots by variants, experience has shown that it has demonstrated here the proximity of convergence with copper. The correlation coefficients of their accumulation with the CSI index in the shoots of both plants were r = 0.82; 0.87 for Cu and r = 0.87; 0.83 for Ni. The proximity of these values indicates the priority nature of the accumulation of these metals in the plant biomass of marigolds, and also characterizes the manifestation of certain interactions between them in contaminated soil by the type of antagonism or synergism.

Effects of biochar application on soil properties and the growth of Melissa officinalis L. under salt stress

Soil salinization is one of the world's most seriously ecological issues. The application of biochar may enhance the properties of the soil and lessen the harm that salt stress causes to plants. In this study, we used the cuttings of Melissa officinalis as experimental materials. The method of pot experiment was used to explore to explore the effects of different concentrations of biochar (0, 10 %, and 20 % w/w) on soil properties and plant physiological characteristics under salt stress (0, 0.20 %, and 0.60 % NaCl+Na2SO4). The results indicate that the physicochemical properties of soil and the plant growth were decreased impacted with increasing salinity level, and these negative impacts were decreased traits were improved with the application of biochar. It was discovered that the application of biochar could increase the soil water holding capacity, total porosity, available P and K content, and soil enzyme activity while also decreasing the soil bulk density under salt stress. Biochar addition promoted the accumulation of plant biomass and the acquisition of nutrients, and reduced Na content in plants. With the addition of biochar, malondialdehyde (MDA) content and electrolyte leakage displayed a significant decrease under salt stress. A reduction in the osmotic substances and secondary metabolite accumulation in the leaves was also evident. The presented results reveal that biochar can contribute to protect M. officinalis against salt stress by alleviating the oxidative stress. Among the test samples, the 20 % biochar application had the best performance, suggesting that this is an advantageous method for improving soil properties and lessening the harm caused by salt stress on M. officinalis.

Neodymium and zinc stimulate growth, biomass accumulation and nutrient uptake of lettuce plants in hydroponics

ABSTRACT We evaluated the effects of neodymium (0.000, 2.885, 5.770 and 8.655 mg · L−1) and zinc (0.1, 0.2 and 0.3 mg · L−1), as well as their interaction on lettuce plants in hydroponics. Applications of 2.885 mg Nd · L−1 and 5.770 mg Nd · L−1 increased plant height, number of leaves and leaf area, as well as fresh and dry stem, root and total biomasses. Root volume was greater in plants treated with 2.885 mg Nd · L−1. With 0.1 mg Zn · L−1, plant height, leaf area and fresh stem, root and total biomass were greater, while applying 0.3 mg Zn · L−1 increased the ratio of dry biomass of stems and roots. Plants exposed to 5.770 mg Nd · L−1 + 0.3 mg Zn · L−1 exhibited greater leaf length. The ratios of fresh and dry biomass of stems and roots increased in plants treated with 8.655 mg · L−1 Nd + 0.3 mg Zn · L−1. Dry biomass weights of stems, roots and total were the highest in plants treated with 20 mg Nd · L−1 + 0.1 mg Zn · L−1. Nd significantly increased foliar concentration of N, P and K. Hence, Nd and Zn improve growth and nutrition.

Morphological, Physiological, and Photosynthetic Differences of Tartary Buckwheat Induced by Post-Anthesis Drought.

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) is a crop of significant interest due to its nutritional value and resilience to drought conditions. However, drought, particularly following flowering, is a major factor contributing to yield reduction. This research employed two distinct Tartary buckwheat genotypes to investigate the effects of post-anthesis drought on growth and physicochemical characteristics. The study aimed to elucidate the response of Tartary buckwheat to drought stress. The findings indicated that post-anthesis drought adversely impacted the growth, morphology, and biomass accumulation of Tartary buckwheat. Drought stress enhanced the maximum photosynthetic capacity (Fv/Fm) and light protection ability (NPQ) of the 'Xiqiao-2' genotype. In response to drought stress, 'Dingku-1' and 'Xiqiao-2' maintained osmotic balance by accumulating soluble sugars and proline, respectively. Notably, 'Xiqiao-2' exhibited elevated levels of flavonoids and polyphenols in its leaves, which helped mitigate oxidative damage caused by drought. Furthermore, rewatering after a brief drought period significantly improved plant height, stem diameter, and biomass accumulation in 'Dingku-1'. Overall, 'Xiqiao-2' demonstrated greater long-term tolerance to post-anthesis drought, while 'Dingku-1' was less adversely affected by short-term post-anthesis drought.

Supplementary Far-Red Light for Photosynthetic Active Radiation Differentially Influences the Photochemical Efficiency and Biomass Accumulation in Greenhouse-Grown Lettuce.

Adding far-red (FR, 700-800 nm) light to photosynthetic active radiation (400-700 nm) proved to be a possible approach to increasing plant biomass accumulation for lettuce production in indoor vertical farms with artificial lighting as a sole-source lighting. However, how FR light addition influences plant growth, development, and metabolic processes and the optimal value of FR photon flux density for greenhouse-grown lettuce under sunlight are still unclear. This work aims to quantify the value of supplementary FR light with different intensities on lettuce morphological and physiological characteristics in a greenhouse. Lettuce 'Dasusheng' (Lactuca sativa L.) was grown in a greenhouse under seven light treatments, including white plus red LEDs with FR photon flux density at 0, 10, 30, 50, 70, and 90 µmol m-2 s-1 (WR, WR + FR10, WR + FR30, WR + FR50, WR + FR70, and WR + FR90, respectively), and lettuce grown with sunlight only was marked as natural light (NL). FR light addition improved the electron transport flux per cross section and performance index (PIabs, PItotal) and decreased the changes in relative variable fluorescence of lettuce leaves compared to plants under NL. Specifically, the PIabs of lettuce leaves were 41%, 41%, 38%, 33%, 26%, and 25% lower under control than in plants under treatments WR + FR90, WR + FR70, WR + FR50, WR + FR30, WR + FR10, and WR, respectively. Leaf number, leaf area, and biomass accumulation of lettuce followed a quadratic function with increasing FR light intensity and were the highest under treatment WR + FR50. The shoot fresh weight and dry weight of lettuce were increased by 111% and 275%, respectively, under treatment WR + FR50 compared to NL. The contents of vitamin C, reducing sugar, total soluble sugar, and starch in lettuce showed a similar trend with biomass accumulation. In conclusion, with commonly used photosynthetic photon flux density (PPFD, 400-700 nm) around 200 μmol m-2 s-1, supplementary FR light intensity of 30~50 μmol m-2 s-1 was suggested to enhance the photochemistry efficiency, biomass accumulation, and carbohydrates' contents in greenhouse-grown lettuce.

Effect of Zinc on Germination, Growth Yield of (Solanum melongena L.)

Eggplant (Solanum melongena L.) is an economically significant crop, valued for its culinary versatility and nutritional content. Understanding the factors that influence its growth is crucial for optimizing agricultural practices and improving yield. Zinc, an essential micronutrient, plays a vital role in various physiological processes within plants, including enzyme activation, photosynthesis, and hormone regulation. This study investigated the effect of zinc supplementation on the growth parameters of eggplant. The experiment was conducted in Botany Lab of Maharishi University of Information Technology, Lucknow in earthen Pots filled with garden soil. Where eggplant seedlings were subjected to different levels of zinc supplementation. Parameters such as plant height, leaf area, root development, and biomass accumulation were measured at regular intervals over the growth period. Results indicated a significant positive correlation between zinc concentration and various growth parameters of eggplant. Seedlings treated with higher zinc concentrations, enhanced leaf expansion, and more extensive root systems compared to those with lower or no zinc supplementation. Furthermore, zinc-treated eggplants displayed improved resistance to certain environmental stressors, suggesting a potential role of zinc in enhancing plant resilience. These findings underscore the importance of adequate zinc supply in promoting the growth and development of eggplant crops, thereby contributing to higher yields and improved agricultural sustainability. Further research is warranted to elucidate the underlying mechanisms of zinc-mediated growth enhancement in eggplant and optimize zinc application strategies for maximum benefit.

BIOCHAR-SUPPORTED IN VITRO CULTURES OF Lavandula officinalis L.

Plants are the sources of valuable biomass that are being currently used in many areas. It is important to produce high biomass for efficient commercial production. Amongst the many factors that affect in vitro propagation of plants, changing or enriching the media composition is one of the commonly used techniques in micropropagation of plants. Biochar is a solid product obtained from organic wastes and because of its rich composition, it has many beneficial effects on plants. In our study, Lavandula officinalis plantlets were subjected to two types of biochars (Geocharged biochar and Biorfe biochar) at 0.5 and 2 g/L concentrations and their effects were investigated by means of plant growth, biomass accumulation and biochemical composition. The results showed that 0.5 g/L concentration of biochar had better effects than 2 g/L concentration and except for biochemical composition, biochar type had no significant effect on plant growth and biomass accumulation. Mean root dry weights and multiple shoot formations/explant enhanced up to 3.7 and 4.17 times higher than the control at 0.5 g/L concentration. Explant browning was also detected lower in biochar-applied media. The differences between biochemical accumulations of different media were also found statistically significant. The total concentrations of phenolics and flavonoids and radical scavenging activities were detected lower when biochars were applied. The total antioxidant concentration was higher in the control group. These findings showed that biochars lowered the negative effects of the culture conditions for L. officinalis plantlets.

Transcriptome profiling reveals the impact of various levels of biochar application on the growth of flue-cured tobacco plants

BackgroundBiochar, a carbon-rich source and natural growth stimulant, is usually produced by the pyrolysis of agricultural biomass. It is widely used to enhance plant growth, enzyme activity, and crop productivity. However, there are no conclusive studies on how different levels of biochar application influence these systems.Methods and resultsThe present study elucidated the dose-dependent effects of biochar application on the physiological performance, enzyme activity, and dry matter accumulation of tobacco plants via field experiments. In addition, transcriptome analysis was performed on 60-day-old (early growth stage) and 100-day-old (late growth stage) tobacco leaves to determine the changes in transcript levels at the molecular level under various biochar application levels (0, 600, and 1800 kg/ha). The results demonstrated that optimum biochar application enhances plant growth, regulates enzymatic activity, and promotes biomass accumulation in tobacco plants, while higher biochar doses had adverse effects. Furthermore, transcriptome analysis revealed a total of 6561 differentially expressed genes (DEGs) that were up- or down-regulated in the groupwise comparison under different treatments. KEGG pathways analysis demonstrated that carbon fixation in photosynthetic organisms (ko00710), photosynthesis (ko00195), and starch and sucrose metabolism (ko00500) pathways were significantly up-regulated under the optimal biochar dosage (600 kg/ha) and down-regulated under the higher biochar dosage (1800 kg/ha).ConclusionCollectively, these results indicate that biochar application at an optimal rate (600 kg/ha) could positively affect photosynthesis and carbon fixation, which in turn increased the synthesis and accumulation of sucrose and starch, thus promoting the growth and dry matter accumulation of tobacco plants. However, a higher biochar dosage (1800 kg/ha) disturbs the crucial source-sink balance of organic compounds and inhibits the growth of tobacco plants.

Deciphering the impact of nitrogen morphologies distribution on nitrogen and biomass accumulation in tobacco plants.

Nitrogen (N) distribution in plants is intricately linked to key physiological functions, including respiration, photosynthesis, structural development, and nitrogen storage. However, the specific effects of different N morphologies on N accumulation and plant growth are poorly understood. Our research specifically focused on determining how different N morphologies affect N absorption and biomass accumulation. This study elucidated the impact of different application rates (CK: 0 g N/plant; T1: 4 g N/plant; T2: 8 g N/plant) of N fertilizer on N and biomass accumulation in tobacco cultivars Hongda and K326 at different growth stages. Our findings emphasize the critical role of N distribution in various plant parts, including leaves, stems, and roots, in determining the complex mechanisms of N and biomass accumulation in tobacco. We found that in relation to total N, a greater ratio of water-soluble N (N w) in leaves facilitated N accumulation in leaves. In contrast, an increased ratio of SDS (detergent)-insoluble N (N in-SDS) in leaves and non-protein N (N np) in roots hindered this increase. Additionally, our results indicate that a greater proportion of N np in leaves has a negative impact on biomass accumulation in leaves. Furthermore, elevated levels of N in-SDS, N w, and N np in roots, and N np in leaves adversely affected biomass accumulation in tobacco leaves. The Hongda cultivar exhibited greater biomass and N accumulation abilities as compared to K326. Our findings highlight the significant role of distribution of N morphologies on plant growth, as well as N and biomass accumulation in tobacco plants. Understanding N distribution allows farmers to optimize N application, minimizing environmental losses and maximizing yield for specific cultivars. These insights advance sustainable agriculture by promoting efficient resource use and reducing environmental impact.

Meta-analysis of nanomaterials and plants interaction under salinity stress.

Salinity stress threatens global food security, requiring novel and sustainable approaches for its mitigation. Over the past decade, nanomaterials (NMs) have emerged as a promising tool to mitigate salinity stress in plants. However, their use has been questioned in terms of whether they really benefit plants or are phytotoxic. Here, we specifically ask whether NMs can help ameliorate plant salinity stress. We use a multivariate meta-analysis of 495 experiments from 70 publications to assess how NMs interact with plants under salinity stress, with a focus on plant biomass accumulation and yield. We also analyzed the influence of NM type, dosage, application method, plant species and families, and growth media on the NM-plant interaction under salinity stress. We demonstrate that NMs enhance plant performance and mitigate salinity stress when applied at lower dosages. However, NMs are phytotoxic at higher dosages and may worsen salinity stress. Also, plant responses to NMs vary across plant species, families, and NM types. We propose a dose-dependent hypothesis to account for the effect of NMs on plant growth under salinity stress and highlight the knowledge gaps and research needs in this field.

Soil amendments influence early plant survival and growth in reclamation of severely degraded lands by gold mining in the Peruvian Amazon

Gold mining has been causing the most severe impacts on the soils of the Peruvian Amazon. It has created challenges for their recovery. In this context, soil amendments could play a crucial role in plant establishment in post-mining soils. The study aimed to analyze the effects of two amendments on the early plant survival and growth of seven species in the reclamation of severely degraded lands by gold mining in the Southeastern Peruvian Amazon. The study was based on a completely randomized block design, including 2-amendment treatments (T1: sawdust + island guano manure and T2: T1 + organic soil + hydrogel) and a control. The plant survivorship, height growth, diameter growth, and biomass accumulation were measured. This study found that amendments may be effective at increasing survivorship and plant growth in degraded lands by gold mining in the Peruvian Amazon. The amendments increased the survival, diameter, height, and biomass of most plant species in the study. In general, survivorship and plant growth in T2 were high compared to T1. At the end of the experiment, the highest survivorship was for an Indigofera suffruticosa and Crotalaria pallida (>80%). The diameter growth was higher in T2 than in T1. The species growing fastest in diameter (>1.5 cm) were Crotalaria cajanifolia, C. pallida and Ochroma pyramidale. Soil amendments provided similar effects on height for most species except for I. suffruticosa. Therefore, C. pallida, I. suffruticosa, C. cajanifolia and O. pyramidale are key species to be considered in reforestation and/or restoration initiatives, due to its potential to acclimate and establish itself in severely degraded areas.

Heavy metal accumulation in root and shoot tapioca plant biomass grown in agriculture land situated around the magnesite mine tailings

Heavy metal pollution in soil has emerged as a major environmental concern. This can be attributed to human activities such as mining, modern agriculture, and industrialization. This study was conducted to determine how heavy metals spread from mine tailings to surrounding farmland. Metal absorption and accumulation were also investigated in the root and shoot biomass of tapioca crops grown in those farmlands. Metal concentrations in MTAS1 were 85.3 ± 1.2, 45.8 ± 1.5, 134.8 ± 1.7, 92.4 ± 2.2, and 78.95 ± 1.4 mg kg-1, respectively. Heavy metal concentrations in MTAS2 and MTAS3 were found to be 79.62 ± 1.6, 75.4 ± 1.5, 41.31 ± 1.1, 47.8 ± 1.6, 142.5 ± 2.1, 128.4 ± 1.4, 86.2 ± 1.9, 79.5 ± 1.3, and 83.4 ± 1.2 mg kg-1, respectively. Tapioca crop shoot and root biomass grown at these metal polluted sites absorbed and accumulated significant amounts of Cd, Cu, Zn, Pb, Ni, and Mn. Notably, the metal content of the tapioca crop's root and shoot biomass exceeded national standards.

Evaluation of Phytoremediation in the Ogoni Wasteland of Southern Nigeria

Phytoremediation offers an effective strategy for managing environmental degradation in the Ogoni wastelands of southern Nigeria, but its benefits and socio-economic implications have not been adequately studied. This study aims to investigate the effectiveness of phytoremediation techniques on soil contamination and community perception and participation in environmental restoration efforts. Soil samples were collected from several sites in Ogoni wasteland, and pollutant concentrations were analyzed by gas chromatography and mass spectrometry. Selected plant species were used for phytoremediation interventions, and microbial activity was assessed using CO2 production rates. Household surveys and interviews were conducted to measure perceptions of community membership and involvement in correctional programs. Analysis of soil samples revealed a significant decrease in contaminant concentrations after phytoremediation, with average initial concentrations decreasing to 23.456 mg/kg and plant biomass accumulation rates of 0.567 kg/sq m returning to 4.901 kg/m², an indication of differences in activity of various organisms in pollutant uptake. After phytoremediation, the changes showed an increasing trend, with CO2 emissions increasing from 0.567 mg CO2/g/hr to 1.345 mg CO2/g/hr. The household survey showed a positive attitude towards the effectiveness of phytoremediation, with an average score of 4.012 on a scale of 1 to 5. Research findings show that phytoremediation can be a sustainable solution for soil pollution in the Ogoni wastelands. These results contribute to the existing body of knowledge by providing empirical evidence and insights into the environmental, social, and economic dynamics of ecological restoration in conflict zones on the background.

Mild to moderate drought stress reinforces the role of functional microbiome in promoting growth of a dominant forage species (Neopallasia pectinata) in desert steppe.

Desert steppe ecosystems are prone to drought stress, which influences the ecological balance and sustainable development of grasslands. In addition to directly restrict plant growth, drought stress indirectly impacts plant fitness by altering the diversity and function of root-associated microbiomes. This begs the question of whether the functional microbiome of forage plants, represented by synthetic microbial communities (SynComs), can be leveraged to mitigate drought stress in desert steppes and promote the ecological restoration of these fragile ecosystems. A pot experiment was conducted to evaluate the role of SynComs in improving the plant growth and drought stress resistance of Neopallasia pectinata (Pall.) Poljak in desert steppe in Inner Mongolia, China. Six SynComs were derived from the rhizosphere and root endosphere of 12 dominant forage species in the desert steppe. Each SynCom comprised two to three bacterial genera (Bacillus, Protomicromonospora, and Streptomyces). We examined the capacities of different SynComs for nutrient solubilization, phytohormone secretion, and enzymatic activity. Under no water stress (75% soil water holding capacity, WHC), single strains performed better than SynComs in promoting plant growth in terms of stem diameter, root length, and plant dry weight, with the greatest effects observed for Streptomyces coeruleorubidus ATCC 13740 (p < 0.05). However, under mild to moderate drought stress (55% and 35% WHC), SynComs outperformed single strains in enhancing plant biomass accumulation and inducing the production of resistance-related substances (p < 0.05). No significant effect of single strains and SynComs emerged under extreme drought stress (20% WHC). This study underscores the potential of SynComs in facilitating forage plants to combat drought stress in desert steppe. Mild to moderate drought stress stimulates SynComs to benefit the growth of N. pectinata plants, despite a soil moisture threshold (21% WHC) exists for the microbial effect. The use of SynComs provides a promising strategy for the ecological restoration and sustainable utilization of desert steppes by manipulating the functional microbiome of forage plants.

Tall wheatgrass response toward phosphorus deficiency: a constraint to its use as a forage resource in marginal soils

Tall wheatgrass is cultivated for pasture in marginal areas around the world due to its tolerance to abiotic stress including seasonal droughts and floods, as well as saline and alkaline soils. However, there is concern about its biomass productivity, which often does not exceed that of natural pastures. In this work we hypothesize that tall wheatgrass is a plant more sensitive to low P availability than commonly assumed. A glasshouse sand culture experiment was conducted to analyze morpho-physiological responses of tall wheatgrass to different P availability levels: 1 µmol L−1 phosphorus (severe deficiency, P1), 10 µmol L−1 phosphorus (representative value of soil solution in the region, P10) and 500 µmol L−1 phosphorus (full P supply, P500). Our results show that both limiting P conditions strongly decreased plant development and biomass accumulation, and altered above- and below-ground morphology, in comparison with P500 plants. The latter, in turn, had relative growth rate values comparable to those of other cultivated grasses under non-limiting conditions. In both P-deficient treatments, plant development was severely delayed starting from leaf number 3, even when P concentration in the pseudostem at early stages was similar or even higher than that of P500 plants. Our results suggest that developmental inhibition of tall wheatgrass at low P supply may be the consequence of a specific plant response to P concentration in soil solution, rather than to direct P starvation in plant tissues, and underlines the need of improvement of this species to enhance productivity in this environment.