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This study used a potted experiment to apply biochar to black soil (BCS) and saline-alkali soil (BSAS) in Northeast China, with a dosage of 0 and 300 g biochar/pot applied, respectively. The original black soil (CS) and saline-alkali soil (SAS) were used as controls to investigate the effects of different particle sizes of soil aggregates on the activity of enzymes related to carbon, nitrogen, and phosphorus cycle. Compared with CS and SAS, the soil organic matter (SOM) values for biochar added into the black soil (BCS) and saline-alkali soil (BSAS) treatments were increased significantly by 41.86 % and 31.98 %. Compared with CS, BCS significantly increased the polyphenol oxidase and ß-1,4-glucosidase activity. Polyphenol oxidation activity, endo-1,4-ß-D-glucanohydrolase activity, ß-1,4-glucosidase activity and xylanase activity are more active in particles with a diameter of >2 mm. The alkaline phase activity and Coenzyme activity with BCS treatment was highest in soil aggregates with sizes of 1~2 mm and >5 mm, respectively. Mantel test analysis shows a highly significant effects between SOM and total nitrogen content (TN) with soil nitrogen, phosphorus, and potassium cycling. Therefore, from the perspective of soil enzyme activities, application of biochar is more effective in promoting soil bio-fertility in northeastern soil of China. Biochar to the soil is more likely to promote the improvement of soil biological fertility. [ABSTRACT FROM AUTHOR]

In this paper, we consider the stochastic nutrient–phytoplankton–zooplankton model with nutrient cycle. In order to take stochastic fluctuations into account, we add the stochastic increments to the variations of biomass of nutrition, phytoplankton and zooplankton during time interval Δ t , thus we obtain the corresponding stochastic model. Subsequently, we explore the existence, uniqueness and stochastically ultimate boundness of global positive solution. By constructing suitable Lyapunov function, we also obtain V-geometric ergodicity of this model. In addition, the sufficient conditions of exponential extinction and persistence in the mean of plankton are established. At last, we present some numerical simulations to validate theoretical results and analyze the impacts of some important parameters. [ABSTRACT FROM AUTHOR]

Organic N (oN, e.g., amino acids) is an important N-resource for plants in soils replete with oN but not inorganic N (iN; i.e., NH4+ and NO3−), such as cold ecosystems with temperature-limited soil decomposition rates. However, sub-Antarctic literature assumes that plants only acquire iN, potentially underestimating plant-available N. We hypothesised that Marion Island (− 46.90°, 37.75°) grasses (Polypogon magellanicus, Poa cookii, Agrostis stolonifera and Poa annua) acquire oN and that oN relative to iN provision affects plant growth. We investigated oN and iN uptake and growth responses in two hydroponics experiments. In situ N (15N-glycine, 15NO3− and 15NH4+) acquisition was investigated at three field sites with decreasing faunal influence, thus iN input and microbial activity. When plants grown in mire water were supplied with 15N-glycine or 15NO3−, root δ15N enrichment was highest for glycine-supplied plants. In the second hydroponics experiment, plant N-uptake rates (nmol g biomass−1 s−1) were significantly higher for glycine than NO3−, but relative growth rates (g g−1 d−1) lower on glycine. There were species-specific biomass allocation responses to N concentration (4 mM and 0.4 mM) and N-form (glycine and NO3−). Glycine-supplied grasses at the low iN concentration field sites had significantly higher δ15N enrichment relative to those at sites with high iN, suggesting higher oN uptake when iN is limiting. We demonstrate the importance of accounting for oN acquisition in the sub-Antarctic. As a system with high soil oN relative to iN, plants may predominantly meet N-demands through oN rather than iN acquisition. [ABSTRACT FROM AUTHOR]

Chinese fir (Cunninghamia lanceolata) is one of the most important tree species for the timber use in China. In recent years, C. lanceolata plantations have faced to the severe soil fertility degradation and declining productivity due to unsustainable afforestation. Compared with monocultures, mixed plantations between Chinese fir and other tree species have obvious advantages in terms of stand stability, resistance to diseases and insect pests, improvement of forest productivity, and utilization of multiple benefits of forests. The establishment of mixed-species forests is an ideal way to solve the problems such as the decline of productivity in C. lanceolata plantations. We summarized the research results of mixed forests between C. lanceolata and other tree species from 1985 to 2021 in China, and analyzed the effects of mixed plantation on the soil physical and chemical properties, nutrient cycling, microorganisms, enzyme activities and productivity. It was found that mixed-species plantation could balance the soil micro-ecology and increase the content of soil organic matter, which improved soil fertility and productivity. These results can provide a theoretical basis for changing the current situation of monoculture and realizing the potential ecological benefits of Chinese fir forest. [ABSTRACT FROM AUTHOR]

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ABSTRACT Garlic (Allium sativum) is normally grown under conventional tillage (CT) with soil being excessively mixed by plowing and harrowing operations that degrade soil structure, increase production costs, and increase environmental contamination. Alternatively, cover crops can be grown and their residues placed on soil surface, enabling garlic to be grown under no-tillage (NT) system. However, for subtropical climate there is little information on the impacts of tillage systems and cover crop species, particularly of their decomposition process and nutrients release, on garlic nutritional status and yield. This study aimed to evaluate garlic yield, and the decomposition rate and nutrient release from aboveground residues of cover crops cultivated in CT and NT methods, in a subtropical climate. Pearl millet (Pennisetum glaucum), bean (Phaseolus vulgaris) and sunn hemp (Crotalaria ochroleuca) were cultivated as cover crops previous to garlic, under CT or NT, for two consecutive years in the same area. The highest dry matter yield and nutrient release by cover crops were observed for millet and sunn hemp. The highest accumulations of P and K were observed in millet residue. Total garlic yield averaged 16.2 Mg ha-1 yr-1 and was affected neither by tillage method nor by cover crop species. The yield of marketable garlic was higher when soil was covered with bean residue in NT. Yield of non-marketable garlic was higher under CT in the first year, when high precipitation occurred shortly before harvest. The highest residue decomposition and nutrient release rates were observed under CT, in the three cover crop species. No-tillage increases marketable yield of garlic and the residence time of cover crop residues. We recommend cultivation in NT systems using cover crops, thus increasing marketable garlic yield and nutrient cycling.

This review provides an overview of grassland studies on the effects of manure application and herbivore excreta on plant and soil properties in temperate grasslands. Grass biomass from grazing or mowing is mainly used for animal products such as milk or meat, as well as for energy or raw materials for biorefineries. Manure application or grazing has a significant impact on several plant and soil properties. There are effects on soil chemical properties, such as increased carbon sequestration, improved nutrient availability, and increased pH. Additionally, several physical soil properties are improved by manure application or grazing. For example, bulk density is reduced, and porosity and hydraulic conductivity are greatly improved. Some biological parameters, particularly microbial biomass and microbial and enzyme activity, also increase. The use of manure and grazing can, therefore, contribute to improving soil fertility, replacing mineral fertilizers, and closing nutrient cycles. On the other hand, over-application of manure and overgrazing can result in a surplus of nutrients over plant needs and increase losses through emission or leaching. The lost nutrients are not only economically lost from the nutrient cycle of the farm but can also cause environmental damage. [ABSTRACT FROM AUTHOR]

In recent decades, microplastics (MPs < 5 mm) are ubiquitous and considered a serious emerging environmental problem. However, due to the limited recovery and long-lasting durability MPs, debris is frequently accumulating in riverine ecosystems, thereby impacting microbial activity and its communities. The presence of MPs may alter the microbial richness, variety, and population, thereby impacting the transformation of biogeochemical cycles. The occurrence, fate, and transport of MPs in marine and terrestrial ecosystems and their impact on biogeochemical or nutrient cycling are reported in the scientific fraternity. Yet, the global scientific community is conspicuously devoid of research on impact of MPs on riverine greenhouse gas (GHG) emissions. The presented view point provides a novel idea about the fate of MPs in the riverine system and its impact on GHG emissions potential. Literature reveals that DO and nutrients (organic carbon, NH4+, NO3−) concentrations play an important role in potential of GHG emission in riverine ecosystems. The proposed mechanism and research gaps provided will be highly helpful to the hydrologist, environmentalist, biotechnologist, and policymakers to think about the strategic mitigation measure to resolve the future climatic risk. [ABSTRACT FROM AUTHOR]

Biochar is usually considered as an organic improver which can improve soil and increase crop yields. However, the unrestricted application of biochar to normal-fertility farmland will cause chemical stress on crops and affect agricultural production. At present, the effects and mechanisms of high-dose applications of biochar on rice (Oryza sativa L.) production and soil biological characteristics have not been fully studied. In this greenhouse pot experiment, combined with soil microbial metagenomics, three treatments in triplicates were conducted to explore the responses of rice production, soil chemical properties, and soil biological properties to high-dose applications of biochar (5%, w/w) prepared using peanut waste (peanut hulls and straw). The results show that peanut hulls, with a loose texture and pore structure, are a raw material with stronger effects for preparing biochar than peanut straw in terms of its physical structure. In a rice monoculture system, high-dose applications of biochar (5%, w/w) can slightly increase the grains per spike, while significantly inhibiting the spike number per pot and the percentage of setting. High-dose applications of biochar also have significant negative effects on the diversity and stability of soil bacterial and archaeal communities. Moreover, the microbial metabolism and nutrient cycling processes are also significantly affected by changing the soil carbon/nitrogen ratio. This study discusses the response mechanisms of rice production and soil biology to high-dose biochar applications, and complements the understanding of irrational biochar application on agricultural production and land sustainability. [ABSTRACT FROM AUTHOR]

ABSTRACT Previous cultivation of sorghum (Sorghum bicolor), Congo grass (Urochloa ruziziensis), and palisade grass (Urochloa brizantha cv. ‘Marandu’) may influence soybean (Glycine max) agronomic performance. The present work evaluated the decomposition of sorghum, grass, and sorghum intercropped with grass in the off-season to improve soybean yield in integrated crop systems in the Brazilian Cerrado and their dry matter production. This study was conducted in Planaltina, DF, in Central-West Brazil, on a Typical Acrustox soil from Mar 2010 until Feb 2012. The experimental design was a randomized block, with six crop systems before soybean: fallowing, sorghum, palisade grass (alone or intercropped with sorghum), and Congo grass (alone or intercropped with sorghum) with four replicates. Soybean agronomic performance, the crop systems’ dry mass, and its decomposition rate were estimated over two years. Higher soybean grain yields were observed in cropping systems including Congo grass alone (3,349 kg ha–1) or intercropped with sorghum (3,317 kg ha–1). Sorghum intercropped with palisade grass produced 18,702 kg ha–1 of dry matter and 64.9 % (on average) of soil coverage during the soybean cycle. However, the highest lignin content was observed in sorghum intercropped with Congo grass (5.1 % on average). The results indicate that the cultivation of Congo grass, either alone or intercropped with sorghum, improves the agronomic performance of soybean in succession, compared to sorghum alone or palisade grass (alone or intercropped with sorghum). The intercropped systems provided the best nutrient efficiency use aiming at sustainable agriculture in the Cerrado region.

Bees provide important ecological services, and many species are threatened globally, yet our knowledge of wild bee ecology and evolution is limited. While evolving from carnivorous ancestors, bees had to develop strategies for coping with limitations imposed on them by a plant‐based diet, with nectar providing energy and essential amino acids and pollen as an extraordinary, protein‐ and lipid‐rich food nutritionally similar to animal tissues. Both nectar and pollen display one characteristic common to plants, a high ratio of potassium to sodium (K:Na), potentially leading to bee underdevelopment, health problems, and death. We discuss why and how the ratio of K:Na contributes to bee ecology and evolution and how considering this factor in future studies will provide new knowledge, more accurately depicting the relationship of bees with their environments. Such knowledge is essential for understanding how plants and bees function and interact and is needed to effectively protect wild bees. [ABSTRACT FROM AUTHOR]

The increasing demand for food has increased dependence on chemical fertilizers that promote rapid growth and yield as well as produce toxicity and negatively affect nutritional value. Therefore, researchers are focusing on alternatives that are safe for consumption, non-toxic, cost-effective production process, and high yielding, and that require readily available substrates for mass production. The potential industrial applications of microbial enzymes have grown significantly and are still rising in the 21st century to fulfill the needs of a population that is expanding quickly and to deal with the depletion of natural resources. Due to the high demand for such enzymes, phytases have undergone extensive research to lower the amount of phytate in human food and animal feed. They constitute efficient enzymatic groups that can solubilize phytate and thus provide plants with an enriched environment. Phytases can be extracted from a variety of sources such as plants, animals, and microorganisms. Compared to plant and animal-based phytases, microbial phytases have been identified as competent, stable, and promising bioinoculants. Many reports suggest that microbial phytase can undergo mass production procedures with the use of readily available substrates. Phytases neither involve the use of any toxic chemicals during the extraction nor release any such chemicals; thus, they qualify as bioinoculants and support soil sustainability. In addition, phytase genes are now inserted into new plants/ crops to enhance transgenic plants reducing the need for supplemental inorganic phosphates and phosphate accumulation in the environment. The current review covers the significance of phytase in the agriculture system, emphasizing its source, action mechanism, and vast applications. [ABSTRACT FROM AUTHOR]

Aims: Once widely used across Europe, grazing of hay meadows is now a rare agricultural practice that is mainly applied in rural regions with maintained traditional agriculture. In this review, we examine the knowledge on grazing hay meadows in the Carpathian Mountains, including its historical distribution, implementation and timing, potential impacts on grassland productivity and biodiversity, and implications for grassland conservation and restoration. Location: The Carpathian Mountains (43.8–50.1°N, 16.9–27.1°E). Methods: We conducted a literature review including biological, ecological, agricultural, ethnological, and historical sources. Results and Conclusions: In each of the seven farming systems that existed in parallel in the Carpathian Mountains before agricultural intensification, grazing of hay meadows was applied regularly. Spring, autumn, and occasionally summer grazing, along with corralling and manuring of hay meadows, were integral parts of these systems, adapted to the seasonal movement of dairy farms across various agroecosystems. The data reviewed provide insight into the role of animals in hay meadow management, as well as how the breakdown of these historical farming systems is impacting local biodiversity, the economy, and the community. According to the literature sources, grazing hay meadows has numerous positive impacts on grassland biodiversity, including suppressing fast‐growing competitors, reducing the accumulation of litter, increasing the availability of germination gaps, dispersing seeds through zoochory, supporting ground‐nesting birds through later mowing, and promoting the regeneration of plants from seeds. From this perspective, the combination of mowing and grazing can be considered a promising tool in current grassland conservation and restoration efforts. [ABSTRACT FROM AUTHOR]

The study of litter can provide an important reference for understanding patterns of forest nutrient cycling and sustainable management. Here, we measured litterfall (leaves, branches, etc.) from a wet, evergreen, broad-leaved forest in Ailao Mountains of southwestern China on a monthly basis for 11 years (2005–2015). We measured the total biomass of litter fall as well as its components, and estimated the amount of C, N, P, K, S, Ca, and Mg in the amount of litterfall. We found that: The total litter of evergreen, broadleaved forest in Ailao Mountains from 2005 to 2015 was 7.70–9.46 t/ha, and the output of litterfall differed between years. This provides a safeguard for the soil fertility and biodiversity of the area. The total amount of litterfall and its components showed obvious seasonal variation, with most showing a bimodal pattern (peak from March to May and October to November). The majority of litterfall came from leaves, and the total amount as well as its components were correlated with meteorological factors (wind speed, temperate and precipitation) as well as extreme weather events. We found that among years, the nutrient concentration was sorted as C > Ca > N > K > Mg > S > P. The nutrient concentration in the fallen litter and the amount of nutrients returned showed a decreasing trend, but the decreasing rate was slowed through time. Nutrient cycling was influenced by meteorological factors, such as temperature, precipitation, and wind speed, but the nutrient utilization efficiency is high, the circulation capacity is strong, and the turnover time is short. Our results showed that although there was nutrient loss in this evergreen, broad-leaved forest, the presence of forest litterfall can effectively curb potential ecological problems in the area. [ABSTRACT FROM AUTHOR]

This review provides an overview of grassland studies on the effects of manure application and herbivore excreta on plant and soil properties in temperate grasslands. Grass biomass from grazing or mowing is mainly used for animal products such as milk or meat, as well as for energy or raw materials for biorefineries. Manure application or grazing has a significant impact on several plant and soil properties. There are effects on soil chemical properties, such as increased carbon sequestration, improved nutrient availability, and increased pH. Additionally, several physical soil properties are improved by manure application or grazing. For example, bulk density is reduced, and porosity and hydraulic conductivity are greatly improved. Some biological parameters, particularly microbial biomass and microbial and enzyme activity, also increase. The use of manure and grazing can, therefore, contribute to improving soil fertility, replacing mineral fertilizers, and closing nutrient cycles. On the other hand, over-application of manure and overgrazing can result in a surplus of nutrients over plant needs and increase losses through emission or leaching. The lost nutrients are not only economically lost from the nutrient cycle of the farm but can also cause environmental damage.

Biochar is usually considered as an organic improver which can improve soil and increase crop yields. However, the unrestricted application of biochar to normal-fertility farmland will cause chemical stress on crops and affect agricultural production. At present, the effects and mechanisms of high-dose applications of biochar on rice (Oryza sativa L.) production and soil biological characteristics have not been fully studied. In this greenhouse pot experiment, combined with soil microbial metagenomics, three treatments in triplicates were conducted to explore the responses of rice production, soil chemical properties, and soil biological properties to high-dose applications of biochar (5%, w/w) prepared using peanut waste (peanut hulls and straw). The results show that peanut hulls, with a loose texture and pore structure, are a raw material with stronger effects for preparing biochar than peanut straw in terms of its physical structure. In a rice monoculture system, high-dose applications of biochar (5%, w/w) can slightly increase the grains per spike, while significantly inhibiting the spike number per pot and the percentage of setting. High-dose applications of biochar also have significant negative effects on the diversity and stability of soil bacterial and archaeal communities. Moreover, the microbial metabolism and nutrient cycling processes are also significantly affected by changing the soil carbon/nitrogen ratio. This study discusses the response mechanisms of rice production and soil biology to high-dose biochar applications, and complements the understanding of irrational biochar application on agricultural production and land sustainability.

Cover cropping is a promising and sustainable agronomic practice to ameliorate soil health and crop performances in agro-ecosystems. Indeed, cover crops (CCs) may regulate several ecosystem services such as nutrient cycling, soil fertility, moderation of extreme meteorological events, pollination, and climate and water regulation; in addition, CCs are also used as forage crops and have considerable effects on plant and soil biodiversity. However, to achieve the desired effects on agro-ecosystems, cover cropping should be carefully adopted by considering the specie choice, period of cultivation, and termination method based on site, farm, or purpose-specific. The main objective of this manuscript is to analyze the effects of modern agriculture on soil and environmental health and how cover crops can support sustainable cropping systems and global food security. In addition, it focuses on how the incorporation of cover crops into conventional cropping systems can help in the diversification of crops and assist in mitigating the environmental effects of cropping systems. Finally, this review thoroughly investigates the potential effects of CCs on environmental sustainability, which can be an important source of information for sustainable crop production and food security. [ABSTRACT FROM AUTHOR]

The traditional logic behind effective microorganism is based on a media inoculation with mixed cultures of beneficial microorganisms to create a more favorable environment for plant growth and health when the media is the soil. Following this rationale, other research works have been focused on studying the effect of effective microorganisms when they are used as manure stabilizing agents, in some cases by including them in animal diets, reporting, in all cases, beneficial properties. However, the use of effective microorganisms is not yet widespread. One reason may be that no rigorous research has so far been done on the actual utility of these mixed cultures on manure stabilization and crop production. In this work, the potential uses of effective microorganisms are shown with the focus on evaluating the influence of these mixed cultures on the biostabilization of manure before its use as fertilizer. This work also presents some new perspectives on the role and application of effective microorganisms as microbial inoculants to achieve a microbiological balance of manure so that it can improve its quality, increasing production and protection of crops when applied as fertilizer, helping to conserving natural resources and creating a more sustainable agriculture and environment. Finally, this document also reviews strategies on how to improve the effect of effective microorganisms after their inoculation into the soil as part of the manure. [ABSTRACT FROM AUTHOR]

To understand the intricacies of nutrient cycling and advance grassland restoration strategies, this study delves into the varying responses of leaf, litter, and root ecological stoichiometries to different durations of grazing exclosure (GE) on the ecologically vital Qinghai-Tibetan Plateau in eastern China. The investigation encompassed GE durations of 0 (seasonal grazing), 13, 22, and 39 years, revealing pivotal alterations in ecological stoichiometries. Notably, GE markedly augmented leaf and root carbon (C) levels and the carbon to nitrogen (C:N) ratio, while diminishing leaf and root nitrogen (N), and root N to phosphorus (N:P) ratios. Intriguingly, with prolonged GE, root C and C:N exhibited a minor decline, and root N slightly increased, albeit remaining significantly lower than in seasonally grazed areas. Leaf N, along with litter P, C:P, and N:P ratios, displayed remarkable stability over time. This suggests that ecological stoichiometries of different plant components responded differently to GE duration. Across plant components, soil NH 4 + N emerged as a predominant factor influencing their stoichiometries, underscoring the complex interplay between vegetation and soil. There was the interconnectedness of C, N, and P among leaf, litter, and roots, highlighting understanding of these elements' cycles. This research, the first of its kind to assess the impact of extensive GE durations on leaf, litter, and root ecological stoichiometries on the Qinghai-Tibetan Plateau, offers insights for understanding ecological stoichiometries at the ecosystem level or between the above-ground part and below-ground part and for alpine grassland management. • Response of leaf, litter, and root stoichiometries to GE durations was examined. • Leaf and root stoichiometries were relatively sensitive to GE durations. • Leaf and root C and C:N increased but N and P decreased as GE duration extended. • Litter P, C:P, and N:P varied little across GE durations. • Leaf, litter, and root ecological stoichiometries were mainly regulated by NH 4 + N. [ABSTRACT FROM AUTHOR]

Viruses are ubiquitous and believed to play pivotal roles in soil ecosystems. However, variations in composition and function of viruses in adjacent paddy and upland soils remain largely unexplored. Thus, we aimed to compare the viral diversity and function in four pairs of paddy and upland soil samples by linking soil viromes with soil properties. Microviridae was the most abundant virus family in both soil samples. The proportion of Genomoviridae was larger, and that of Siphoviridae was smaller in upland soils. Moreover, upland soils harbored more virulent viruses, whereas paddy soils harbored more temperate viruses and viral genera. Available phosphorus content and pH were the dominant factors contributing to the viral community structures in upland and paddy soils, respectively. Viruses in upland soils encoded metabolic genes for degrading cell components, whereas viruses in paddy soils encoded genes for metabolizing amino acids. Additionally, viruses in paddy fields carried more carbohydrate-active enzyme genes and had broader host ranges. Hence, given the concentration of dissolved organic carbon, the difference in viral lifestyles between upland and paddy soils suggest that viral-induced cell lysis can influence nutrient availability. These findings provide a scientific basis for increasing virus-mediated microbial-derived carbon storage in soils by regulating nutrient availability. [ABSTRACT FROM AUTHOR]

Microbial communities in desert riparian forest ecosystems have developed unique adaptive strategies to thrive in harsh habitats shaped by prolonged exposure to abiotic stressors. However, the influence of drought stress on the functional and metabolic characteristics of soil rhizosphere microorganisms remains unknown. Therefore, this study aimed to investigate the effects of drought stress on soil biogeochemistry and metabolism and analyze the relationship between the biogeochemical cycle processes and network of differentially-expressed metabolites. Using metagenomics and metabolomics, this study explored the microbial functional cycle and differential metabolic pathways within desert riparian forests. The predominant biogeochemical cycles in the study area were the Carbon and Nitrogen cycles, comprising 78.90 % of C, N, Phosphorus, Sulfur and Iron cycles. Drought led to increased soil C fixation, reduced C degradation and methane metabolism, weakened denitrification, and decreased N fixation. Furthermore, drought can disrupt iron homeostasis and reduce its absorption. The differential metabolic pathways of drought stress include flavonoid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and starch and sucrose degradation. Network analysis of functional genes and metabolism revealed a pronounced competitive relationship between the C cycle and metabolic network, whereas the Fe cycle and metabolic network promoted each other, optimizing resource utilization. Partial least squares analysis revealed that drought hindered the expression and metabolic processes and functional genes, whereas the rhizosphere environment facilitated metabolic expression and the functional genes. The rhizosphere effect primarily promoted metabolic processes indirectly through soil enzyme activities. The integrated multi-omics analysis further revealed that the effects of drought and the rhizosphere play a predominant role in shaping soil functional potential and the accumulation of metabolites. These insights deepen our comprehension of desert riparian forest ecosystems and offer strong support for the functionality of nutrient cycling and metabolite dynamics., (Copyright © 2024. Published by Elsevier B.V.)

A Closed Aquatic Ecosystem (CAES) housed an aquatic plant Ceratophyllum demersum, zebrafish (Danio rerio), and microbes that were simultaneously obtained with the zebrafish, and it was used to study the operation of the ecosystem. The results indicated that the CAES can operate steadily for about 4 weeks. The dissolved oxygen (DO), pH, and conductivity values of the ecosystem regularly oscillated, while the total nitrogen of the water decreased and the total phosphate slightly increased. Additionally, the chemical oxygen demand (COD, a measure of organic compounds) of the water after the experiment increased to 39 times more than that of the water before the experiment. The meta-genomic data showed that the number of genera decreased by 38 % and the top 10 most abundant genera were almost completely different before and after the experiment, which demonstrated a great shift in the microbes during the operation process. These results suggested that although the CAES operated steadily during the 28-day experiment, there were more organic materials and less nitrogen in the water by the end of the experiment, which may have influenced the structure and operation of the ecosystem. Thus, it is necessary to remove superfluous plant biomass from the CAES and supply nitrogen to keep the ecosystem stable., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Committee on Space Research (COSPAR). Published by Elsevier B.V. All rights reserved.)

Abstract Selective logging is one of the main human activities that are drastically modifying tropical forests around the world. Reduced-impact logging emerged as a rational model of timber harvesting that reduces the impacts on the ecosystems and contributes to the conservation of natural resources. Nevertheless, this type of activity may still alter the forest structure, nutrient cycling, soil drainage, and other important ecosystem processes. Here, we aimed at testing the effects of selective logging on litter deposition in central Brazilian Amazonia. We estimated litter production during one dry and one rainy season in 11 sites logged between 2003 and 2017 and one unlogged site. Mean litter deposition was greater during the dry season. Although litter deposition rates varied between a few study sites, this variation was independent of the time after logging. The results suggest that the low logging intensity in the study site (16.8 m³/ha) had no intense impacts on litter deposition. Reduced-impact logging may be an alternative for the use of forest resources in Amazonian forests without compromising nutrient cycles.

Natural tropical landscapes have been continuously altered by land use change and other climate factors. Forest management practices have transformed massive tropical forests into rubber plantations throughout mainland Southeast Asia and Southwest China. However, the effect of the forest-to-plantation conversion on ecosystem functions associated with plant litter is limited. Here, we compare litterfall production, decomposition, nutrient return and nutrient use efficiency between a tropical natural forest (TNF) and a monoculture rubber plantation (MRP) in Xishuangbanna (China) over three years. Annual mean litterfall production was significantly higher in TNF (10.92 Mg ha−1 yr−1) than in MRP (5.23 Mg ha−1 yr−1). Production of leaf litter was positively correlated to that of total litterfall, suggesting that leaf litter could be reliably estimated from total litterfall. Temperature and solar radiation are dominant drivers of seasonal variation of litterfall production. The litterfall production was more sensitive to climate variables in MRP. The average stand litter and the decomposition quotient were 1.8 and 1.2 times greater in TNF than in MRP, respectively. The total nutrient return to the forest floor was 2.1 times higher in TNF (5.66 Mg ha−1 yr−1) than in MRP (2.76 Mg ha−1 yr−1); the return of each mineral element was significantly lower in MRP relative to TNF. The nutrient return preferentially occurred during the cold and dry seasons, which was consistent with the trend of litterfall. Relatively high N, P, Ca, and Mg use efficiencies were observed in MRP in line with their deficiency in the present tropical soils, indicating that rubber trees likely possess an efficient nutrient uptake mechanism to facilitate their adaption to oligotrophic habitats. Our results suggest that the large scale transformation of tropical forests to rubber plantations could alter the biogeochemical cycles related to litterfall, and thus possibly affect the resilience of ecosystems to climate variation. An increasing organic matter input in rubber monoculture may favor the sustainable development of rubber cultivation.

Abstract Background Biochar is a relatively new soil amendment method in agricultural practices that can improve the ecosystem services of soils. Biochar has commonly been applied to less fertile or contaminated soils, specifically sandy-textured and contaminated sandy soils, to improve their properties. However, the available literature indicates that not all sandy-textured and contaminated sandy soils show the same response to biochar applications, as the sign and size of the effect vary across studies. More specifically, primary studies show heterogeneous and potentially conflicting impacts of biochar application on a set of ecosystem services provided by these types of soils; namely, biomass production, water cycle, nutrient cycle, and climate regulation. Therefore, the objective of the present study is to systematically review the available evidence base to synthesise the impact and drivers of biochar amendments on four specific ecosystem services provided by sandy-textured and contaminated sandy soils. Methods This review follows the guideline of the Collaboration for Environmental Evidence and corresponds to the ROSES (RepOrting standards for Systematic Evidence Synthesis) reporting standard. A comprehensive search strategy will be employed to cover peer-reviewed and gray literature through bibliographic databases, organizational and institutional websites, and web searches. Search terms and strategies have been developed to identify the impact of biochar on the ecosystem services of sandy-textured soils. The search results will be screened first by their title and abstract, and then by their full text. Two literature reviewers will do this based on eligibility criteria. A validity assessment will be conducted to critically appraise and assess the validity of studies using a common validity framework for environmental studies. Data will be extracted from the studies that are found to be valid for the review. Narrative synthesis and meta-analysis will be employed to synthesise the review results.

The pronounced seasonal variation over the Bay of Bengal affects trace metals concentration and distribution. Trace metals distribution in the Bay of Bengal has been best characterized during spring and fall intermonsoon, while limited studies were conducted during the southwest monsoon. This study reports the full-depth profiles of trace metals, including dissolved iron, manganese, lead, cadmium, copper, and zinc (Fe, Mn, Pb, Cd, Cu, and Zn) in the Bay of Bengal (BoB) during southwest monsoon, from July to August 2013. At coastal and ocean scales, transect observations covering the entire water depth provided a comprehensive picture of the circulation and biogeochemical cycles of these elements in seawater during the southwest monsoon. Water samples were obtained from one station in the northeastern Indian Ocean (NR-1) and from three shallow coastal stations with maximum depths <60 m (BA-1, BA-3, and BA-5), as well as from three offshore stations with maximum depths exceeding 2000 m (MY-7, MY-9, and MY-11). In the surface layer (5 m depth), the trace metal concentrations at the shallow near-coastal station BA-5 were higher than those at the ocean station NR-1. Surface trace metal concentrations in offshore regions encompassing stations MY-11, MY-9, and MY-7 were relatively higher than those reported for other seasons in a similar salinity region, indicating seasonal variation associated with freshwater intrusion and coastal-derived input. Below the mixed layer depth, the trace metal/phosphate (P) ratio was higher than that previously reported in the eastern Indian Ocean, suggesting an input from continental margins and mildly reducing sediments, particularly for Fe, Mn, and Cu. Moreover, at intermediate depths (190–800 m), where the North Indian Central Water (NICW) is the main water mass, the Cd/P ratio (0.55 ± 0.11 nmol/μmol) deviated from the global trend (∼0.3 nmol/μmol) owing to oxygen-deficient conditions. Intriguingly, at some stations, specifically MY-9 and MY-7, the intermediate dFe concentrations were relatively higher than those at station NR-1 at the same depth. Continental margin sediment, water mass movement, and ventilation may control the transport of Fe from locations with high Fe concentrations, including near the continental shelf (station MY-11 in this study) and the Andaman Sea. • Monsoon dynamics drive seasonal trace metal variations. • Continental margins act as significant dFe sources. • NICW exhibits elevated dFe levels from various sources. • Continuous sediment inputs influence dCu distribution. • Oxygen-deficient conditions affect dCd-phosphate relationship. [ABSTRACT FROM AUTHOR]

The study of litter can provide an important reference for understanding patterns of forest nutrient cycling and sustainable management. Here, we measured litterfall (leaves, branches, etc.) from a wet, evergreen, broad-leaved forest in Ailao Mountains of southwestern China on a monthly basis for 11 years (2005–2015). We measured the total biomass of litter fall as well as its components, and estimated the amount of C, N, P, K, S, Ca, and Mg in the amount of litterfall. We found that: The total litter of evergreen, broadleaved forest in Ailao Mountains from 2005 to 2015 was 7.70–9.46 t/ha, and the output of litterfall differed between years. This provides a safeguard for the soil fertility and biodiversity of the area. The total amount of litterfall and its components showed obvious seasonal variation, with most showing a bimodal pattern (peak from March to May and October to November). The majority of litterfall came from leaves, and the total amount as well as its components were correlated with meteorological factors (wind speed, temperate and precipitation) as well as extreme weather events. We found that among years, the nutrient concentration was sorted as C > Ca > N > K > Mg > S > P. The nutrient concentration in the fallen litter and the amount of nutrients returned showed a decreasing trend, but the decreasing rate was slowed through time. Nutrient cycling was influenced by meteorological factors, such as temperature, precipitation, and wind speed, but the nutrient utilization efficiency is high, the circulation capacity is strong, and the turnover time is short. Our results showed that although there was nutrient loss in this evergreen, broad-leaved forest, the presence of forest litterfall can effectively curb potential ecological problems in the area.

• Increasing amounts of wood ashes from energy production challenge plant owners. • Chemical composition of wood ashes from industrial HP(P) is presented. • Ash quality from natural wood and waste wood combustion is examined. • Fertilizer regulations in EU and selected countries are discussed regarding ash use. • To develop the ash for secondary use, a suitable treatment process is necessary. To achieve a sustainable circular economy for wood ash, the reuse of wood ash in agriculture and forestry is important. To evaluate the usability of ash from the combustion of natural as well as waste wood for application as fertilizer, wood fuel and corresponding ash fraction samples (n = 86) of four industrial wood-fired heat and power plants (>20 MW) were investigated. In different ash fractions, the concentrations of heavy metals (As, Cd, Pb, Ni, Tl, Zn) and plant nutrients (N, P, K, Ca) were assessed with regard to relevant legislation from the European Union and from selected European countries (Germany, Austria and Finland). Depending on fuel composition and combustion kinetics within the respective plants, the investigated ash fractions showed a wide range of nutrient and heavy metal contents. Apart from N which is mainly emitted with the flue gas, plant nutrients were present in substantial concentrations with mean values corresponding to 20% P, 55 % K and >95% Ca content compared to nutrient compound fertilizer. A direct application of most ash fractions from both natural and waste wood combustion is however not possible due to high contents of Cd, Pb and Ni. In order to develop the ash for secondary use, investigation for a suitable treatment process is necessary. An estimation of the nutrient recovery potential from industrial wood energy plants in southwest Germany showed that approx. 3.1% (P), 7.5% (K) and 22.8% (Ca) of raw material for fertilizers could be substituted by ash. [ABSTRACT FROM AUTHOR]

The Songnen Plain is an important agricultural base in China and one of the important areas of distribution of saline-alkaline soils in the cold region. Saline-alkaline soils severely restrict maize growth. This study was to potentially promote the soil nutrient in the maize rhizosphere, microbes diversity, and maize yield by Trichoderma asperellum in saline-alkaline soil of the cold region. In the present study, we applied different amounts of T. asperellum in field experiments for three consecutive years. High-throughput sequencing was used to analyse the impact of Trichoderma on microbes diversity in maize rhizosphere soils. Changes in crop yield and soil nutrients were also monitored. T. asperellum treatment significantly increased the relative abundance of beneficial microbes genera. In the control treatment, the pathogenic microbes were the dominant genera. Pearson's correlation analysis revealed that changes in the soil microbial community composition were closely related to soil nutrients and were highly correlated with T. asperellum treatment concentration. Further, T. asperellum treatment increased crop yield by 4.87-20.26%. These findings suggest that T. asperellum treatment optimised the microenvironment of the maize rhizosphere soil, alleviated microbial community degeneration in cold region saline-alkaline soil, and promoted maize growth.

Many studies have been conducted on the effects of changes in plant diversity and species composition on ecosystem functioning and plant productivity due to climate change. However, a few studies have been conducted on the effects of species shifts on litter decomposition. In this context, we tested (i) the influences of litter species diversity on decomposition, (ii) deviation of litter mixtures decomposition from expected patterns (non-additive effects), and (iii) tree species loss or gain impact on the decomposition process. We performed a complete factorial decomposition experiment in a gradient of tree litter species diversity in a semi-arid Mediterranean oak forest for 550 days. Among species, only C, lignin, and water holding capacity (WHC) values varied significantly in initial litter characteristics. The litter mass loss at the end of the experiment differed significantly between Q. brantii and P. glabra. Initial lignin content and C/N ratio had the main effects on the decomposition rate. Lignin content was the best predictor of the overall decomposition rate in this region. Contrary to other ecosystems where synergistic non-additive effects are dominant, we observed 82% of additive and 18% of non-additive effects on litter mass and chemical components loss. Turnover of plant species due to climate change could negatively affect the litter decomposition and nutrient release from litter mixture in the semi-arid Mediterranean region. [ABSTRACT FROM AUTHOR]

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Abstract Recently, biochar has been widely used for versatile applications in agriculture and environment sectors as an effective tool to minimise waste and to increase the efficiency of circular economy. In the present work, we review the current knowledge about biochar role in N, P and K cycles. Ammonia volatilisation and N2O emission can be reduced by biochar addition. The content of available P can be improved by biochar through enhancement of solubilisation and reduction in P fixation on soil mineral, whilst high extractable K in biochar contributes to K cycle in soil. Liming effect and high CEC are important properties of biochars improving beneficial interactions with N, P and K soil cycle processes. The effectiveness of biochar on N, P and K cycles is associated with biochar properties which are mainly affected by feedstock type and pyrolysis condition.

Archaea are members of most microbiomes. While archaea are highly abundant in extreme environments, they are less abundant and diverse in association with eukaryotic hosts.Nevertheless, archaea are a substantial constituent of plant-associated ecosystems in the aboveground and belowground phytobiome. Only a few studies have investigated the role of archaea in plant health and its potential symbiosis in ecosystems. This review discusses recent progress in identifying how archaea contribute to plant traits such as growth, adaptation to abiotic stresses, and immune activation. We synthesized the most recent functional and molecular data on archaea, including root colonization and the volatile emission to activate plant systemic immunity. These data represent a paradigm shift in our understanding of plant-microbiota interactions.

Cover cropping is a promising and sustainable agronomic practice to ameliorate soil health and crop performances in agro-ecosystems. Indeed, cover crops (CCs) may regulate several ecosystem services such as nutrient cycling, soil fertility, moderation of extreme meteorological events, pollination, and climate and water regulation; in addition, CCs are also used as forage crops and have considerable effects on plant and soil biodiversity. However, to achieve the desired effects on agro-ecosystems, cover cropping should be carefully adopted by considering the specie choice, period of cultivation, and termination method based on site, farm, or purpose-specific. The main objective of this manuscript is to analyze the effects of modern agriculture on soil and environmental health and how cover crops can support sustainable cropping systems and global food security. In addition, it focuses on how the incorporation of cover crops into conventional cropping systems can help in the diversification of crops and assist in mitigating the environmental effects of cropping systems. Finally, this review thoroughly investigates the potential effects of CCs on environmental sustainability, which can be an important source of information for sustainable crop production and food security.

The widespread expansion of the oxygen minimum zone onto shelves has been commonly regarded as a primary cause of benthos extinction in epicratonic sea ecosystems during the Cenomanian–Turonian boundary event (CTBE). However, neither lithology, geochemical proxies, nor micropaleontological data support this hypothesis. Instead, our integrated foraminiferal and dinoflagellate cyst study, corroborated by δ13Corg and δ15Norg data, indicate that the biota were impacted by an abrupt shift to well oxygenated oligotrophic conditions and a collapse of primary productivity in the epicontinental Central European Basin. Because the event was concurrent with the development of extensive and extreme oceanic bottom water anoxia that reached the photic zone in oceanic settings, we infer that the biotic crisis in the shelf seas during Oceanic Anoxic Event 2 (OAE2), and possibly during other OAEs, was triggered by this anomalous nutrient cycling in Earth's oceans. This phenomenon was presumably associated with intensive denitrification combined with anammox activity in the deep "ammonium oceans," which caused a significant loss of biologically reactive nitrogen from the ocean system. Impingement of ammonium‐rich anoxic waters on the photic zone resulted in primary productivity based primarily on ammonium assimilation, as recorded by strongly 15N‐depleted organic matter deposited in the oceans during the CTBE. We propose that, unlike in the oceanic settings, productivity in the well‐oxygenated, oligotrophic epicontinental seas was nitrate‐based, as evidenced by strongly 15N‐enriched organic matter deposited in the contemporaneous epicontinental sea. These very high δ15Norg values (>+5‰) were related to the spreading of shallow oceanic waters carrying 15N‐enriched nitrate onto epicontinental settings. Key Points: A causal link between nutrient‐rich deep oceans and nutrient‐poor epicratonic seas during Oceanic Anoxic Event 2 (OAE2)Influence of abnormal oceanic nutrient cycling during Late Cretaceous OAE2 on shelf biotaResponse of benthic foraminifera and dinoflagellates to oligotrophy during OAE2 [ABSTRACT FROM AUTHOR]

The availability of phosphorus limits primary production in large regions of the oceans, and marine microbes use a variety of strategies to overcome this limitation. One strategy is the production of alkaline phosphatase (APase), which allows hydrolysis of larger dissolved organic phosphorus (DOP) compounds in the periplasm or at the cell surface for transport of orthophosphate into the cell. Cell lysis, driven by grazing and viral infection, releases phosphorus-containing cell components, along with active enzymes that could persist after lysis. The importance of this continued enzymatic activity for orthophosphate regeneration is unknown. We used three model bacteria – Escherichia coli K-12 MG1655, Synechococcus sp. WH7803, and Prochlorococcus sp. MED4 – to assess the impact of continued APase activity after cell lysis, via lysozyme treatment, on orthophosphate regeneration. Direct release of orthophosphate scaled with cell size and was reduced under phosphate-starved conditions where APase activity continued for days after lysis. All lysate incubations showed post-lysis orthophosphate generation suggesting phosphatases other than APase maintain activity. Rates of DOP hydrolysis and orthophosphate remineralization varied post-lysis among strains. Escherichia coli K-12 MG1655 rates of remineralization were 0.6 and 1.2 amol cell–1hr–1 under deplete and replete conditions; Synechococcus WH7803 lysates ranged from 0.04 up to 0.3 amol cell–1hr–1 during phosphorus deplete and replete conditions, respectively, while in Prochlorococcus MED4 lysates, rates were stable at 0.001 amol cell–1hr–1 in both conditions. The range of rates of hydrolysis and regeneration underscores the taxonomic and biochemical variability in the process of nutrient regeneration and further highlights the complexity of quantitatively resolving the major fluxes within the microbial loop.

Grazing exclusion has been applied as a suitable strategy for soil conservation worldwide, mainly on semiarid soils. However, it is unclear how grazing exclusion reduces the negative effects of overgrazing on the microbial community in the Caatinga biome. In our study, we assessed the bacterial community under three different soil managements in a semiarid region of the Brazilian Caatinga biome, as follows: (a) Native Caatinga vegetation (natural); (b) grazing exclusion (exclusion); and (c) overgrazing (grazed). The bacterial community was assessed through the sequencing of the V4 region of the 16S rRNA gene and analyzed soil chemical and physical properties were correlated with the bacterial community structure. Our results demonstrate that exclusion increases the content of soil carbon and nitrogen, and bacterial diversity, while grazed showed a reduction of ~31 and ~43% in organic C, compared to exclusion and natural, respectively. However, the changes in bacterial diversity were more expressive in a specific site (No. 1), suggesting that exclusion strategy could be a context‐dependent and complex approach to protecting or improving Caatinga soils. Moreover, grazed areas might restrain the potential of bacterial diversity to sustain ecosystem functions since nonbeneficial elements increased in grazed treatments, which presented a negative correlation with the bacterial community. Our study provides novel evidence that high‐intensity disturbance by overgrazing could not only reduce soil fertility but it may also restrain bacterial composition, with implications on ecosystem functioning. The Caatinga soil microbiome may be unable to maintain ecosystem services such as plant and animals' development under overgrazing management. [ABSTRACT FROM AUTHOR]