Long-term push-pull cropping system shifts soil and maize-root microbiome diversity paving way to resilient farming system.

BACKGROUND: The soil biota consists of a complex assembly of microbial communities and other organisms that vary significantly across farming systems, impacting soil health and plant productivity. Despite its importance, there has been limited exploration of how different cropping systems influence soil and plant root microbiomes. In this study, we investigated soil physicochemical properties, along with soil and maize-root microbiomes, in an agroecological cereal-legume companion cropping system known as push-pull technology (PPT). This system has been used in agriculture for over two decades for insect-pest management, soil health improvement, and weed control in sub-Saharan Africa. We compared the results with those obtained from maize-monoculture (Mono) cropping system. RESULTS: The PPT cropping system changed the composition and diversity of soil and maize-root microbial communities, and led to notable improvements in soil physicochemical characteristics compared to that of the Mono cropping system. Distinct bacterial and fungal genera played a crucial role in influencing the variation in microbial diversity within these cropping systems. The relative abundance of fungal genera Trichoderma, Mortierella, and Bionectria and bacterial genera Streptomyces, RB41, and Nitrospira were more enriched in PPT. These microbial communities are associated with essential ecosystem services such as plant protection, decomposition, carbon utilization, bioinsecticides production, nitrogen fixation, nematode suppression, phytohormone production, and bioremediation. Conversely, pathogenic associated bacterial genus including Bryobacter were more enriched in Mono-root. Additionally, the Mono system exhibited a high relative abundance of fungal genera such as Gibberella, Neocosmospora, and Aspergillus, which are linked to plant diseases and food contamination. Significant differences were observed in the relative abundance of the inferred metabiome functional protein pathways including syringate degradation, L-methionine biosynthesis I, and inosine 5'-phosphate degradation. CONCLUSION: Push-pull cropping system positively influences soil and maize-root microbiomes and enhances soil physicochemical properties. This highlights its potential for agricultural and environmental sustainability. These findings contribute to our understanding of the diverse ecosystem services offered by this cropping system where it is practiced regarding the system's resilience and functional redundancy. Future research should focus on whether PPT affects the soil and maize-root microbial communities through the release of plant metabolites from the intercrop root exudates or through the alteration of the soil's nutritional status, which affects microbial enzymatic activities.

Moving restoration ecology forward with combinatorial approaches.

Our current planetary crisis, including multiple jointly acting factors of global change, moves the need for effective ecosystem restoration center stage and compels us to explore unusual options. We here propose exploring combinatorial approaches to restoration practices: management practices are drawn at random and combined from a locally relevant pool of possible management interventions, thus creating an experimental gradient in the number of interventions. This will move the current degree of interventions to higher dimensionality, opening new opportunities for unlocking unknown synergistic effects. Thus, the high dimensionality of global change (multiple jointly acting factors) would be more effectively countered by similar high-dimensionality in solutions. In this concept, regional restoration hubs play an important role as guardians of locally relevant information and sites of experimental exploration. Data collected from such studies could feed into a global database, which could be used to learn about general principles of combined restoration practices, helping to refine future experiments. Such combinatorial approaches to exploring restoration intervention options may be our best hope yet to achieve decisive progress in ecological restoration at the timescale needed to mitigate and reverse the most severe losses caused by global environmental change.

Micro/nanoplastics pollution poses a potential threat to soil health.

Micro/nanoplastic (MNP) pollution in soil ecosystems has become a growing environmental concern globally. However, the comprehensive impacts of MNPs on soil health have not yet been explored. We conducted a hierarchical meta-analysis of over 5000 observations from 228 articles to assess the broad impacts of MNPs on soil health parameters (represented by 20 indicators relevant to crop growth, animal health, greenhouse gas emissions, microbial diversity, and pollutant transfer) and whether the impacts depended on MNP properties. We found that MNP exposure significantly inhibited crop biomass and germination, and reduced earthworm growth and survival rate. Under MNP exposure, the emissions of soil greenhouse gases (CO2, N2O, and CH4) were significantly increased. MNP exposure caused a decrease in soil bacteria diversity. Importantly, the magnitude of impact of the soil-based parameters was dependent on MNP dose and size; however, there is no significant difference in MNP type (biodegradable and conventional MNPs). Moreover, MNPs significantly reduced As uptake by plants, but promoted plant Cd accumulation. Using an analytical hierarchy process, we quantified the negative impacts of MNP exposure on soil health as a mean value of -10.2% (-17.5% to -2.57%). Overall, this analysis provides new insights for assessing potential risks of MNP pollution to soil ecosystem functions.

Long-term tropospheric ozone pollution disrupts plant-microbe-soil interactions in the agroecosystem.

Tropospheric ozone (O3 ) threatens agroecosystems, yet its long-term effects on intricate plant-microbe-soil interactions remain overlooked. This study employed two soybean genotypes of contrasting O3 -sensitivity grown in field plots exposed elevated O3 (eO3 ) and evaluated cause-effect relationships with their associated soil microbiomes and soil quality. Results revealed long-term eO3 effects on belowground soil microbiomes and soil health surpass damage visible on plants. Elevated O3 significantly disrupted belowground bacteria-fungi interactions, reduced fungal diversity, and altered fungal community assembly by impacting soybean physiological properties. Particularly, eO3 impacts on plant performance were significantly associated with arbuscular mycorrhizal fungi, undermining their contribution to plants, whereas eO3 increased fungal saprotroph proliferation, accelerating soil organic matter decomposition and soil carbon pool depletion. Free-living diazotrophs exhibited remarkable acclimation under eO3 , improving plant performance by enhancing nitrogen fixation. However, overarching detrimental consequences of eO3 negated this benefit. Overall, this study demonstrated long-term eO3 profoundly governed negative impacts on plant-soil-microbiota interactions, pointing to a potential crisis for agroecosystems. These findings highlight urgent needs to develop adaptive strategies to navigate future eO3 scenarios.

Agroforestry enhances biological activity, diversity and soil-based ecosystem functions in mountain agroecosystems of Latin America: A meta-analysis.

Mountain agroecosystems in Latin America provide multiple ecosystem functions (EFs) and products from global to local scales, particularly for the rural communities who depend on them. Agroforestry has been proposed as a climate-smart farming strategy throughout much of the region to help conserve biodiversity and enhance multiple EFs, especially in mountainous regions. However, large-scale synthesis on the potential of agroforestry across Latin America is lacking. To understand the potential impacts of agroforestry at the continental level, we conducted a meta-analysis examining the effects of agroforestry on biological activity and diversity (BIAD) and multiple EFs across mountain agroecosystems of Latin America. A total of 78 studies were selected based on a formalized literature search in the Web of Science. We analysed differences between (i) silvoarable systems versus cropland, (ii) silvopastoral systems versus pastureland, and (iii) agroforestry versus forest systems, based on response ratios. Response ratios were further used to understand how climate type, precipitation and soil properties (texture) influence key EFs (carbon sequestration, nutrient provision, erosion control, yield production) and BIAD in agroforestry systems. Results revealed that BIAD and EFs related to carbon sequestration and nutrient provisioning were generally higher in agroforestry systems (silvopastoral and silvoarable) compared to croplands and pasturelands without trees. However, the impacts of agroforestry systems on crop yields varied depending on the system considered (i.e., coffee vs. cereals), while forest systems generally provided greater levels of BIAD and EFs than agroforestry systems. Further analysis demonstrated that the impacts of agroforestry systems on BIAD and EFs depend greatly on climate type, soil, and precipitation. For example, silvoarable systems appear to generate the greatest benefits in arid or tropical climates, on sandier soils, and under lower precipitation regimes. Overall, our findings highlight the widespread potential of agroforestry systems to BIAD and multiple EFs across montane regions of Latin America.

Plant-soil synchrony in nutrient cycles: Learning from ecosystems to design sustainable agrosystems.

Redesigning agrosystems to include more ecological regulations can help feed a growing human population, preserve soils for future productivity, limit dependency on synthetic fertilizers, and reduce agriculture contribution to global changes such as eutrophication and warming. However, guidelines for redesigning cropping systems from natural systems to make them more sustainable remain limited. Synthetizing the knowledge on biogeochemical cycles in natural ecosystems, we outline four ecological systems that synchronize the supply of soluble nutrients by soil biota with the fluctuating nutrient demand of plants. This synchrony limits deficiencies and excesses of soluble nutrients, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. In the ecological systems outlined, synchrony emerges from plant-soil and plant-plant interactions, eco-physiological processes, soil physicochemical processes, and the dynamics of various nutrient reservoirs, including soil organic matter, soil minerals, atmosphere, and a common market. We discuss the relative importance of these ecological systems in regulating nutrient cycles depending on the pedoclimatic context and on the functional diversity of plants and microbes. We offer ideas about how these systems could be stimulated within agrosystems to improve their sustainability. A review of the latest advances in agronomy shows that some of the practices suggested to promote synchrony (e.g., reduced tillage, rotation with perennial plant cover, crop diversification) have already been tested and shown to be effective in reducing nutrient losses, fertilizer use, and N2 O emissions and/or improving biomass production and soil carbon storage. Our framework also highlights new management strategies and defines the conditions for the success of these nature-based practices allowing for site-specific modifications. This new synthetized knowledge should help practitioners to improve the long-term productivity of agrosystems while reducing the negative impact of agriculture on the environment and the climate.

Green Waste Compost Impacts Microbial Functions Related to Carbohydrate Use and Active Dispersal in Plant Pathogen-Infested Soil.

The effects of compost on physical and chemical characteristics of soil are well-studied but impacts on soil microbiomes are poorly understood. This research tested effects of green waste compost on bacterial communities in soil infested with the plant pathogen Fusarium oxysporum. Compost was added to pathogen-infested soil and maintained in mesocosms in a greenhouse experiment and replicated growth chamber experiments. Bacteria and F. oxysporum abundance were quantified using quantitative PCR. Taxonomic and functional characteristics of bacterial communities were measured using shotgun metagenome sequencing. Compost significantly increased bacterial abundance 8 weeks after amendment in one experiment. Compost increased concentrations of chemical characteristics of soil, including phosphorus, potassium, organic matter, and pH. In all experiments, compost significantly reduced abundance of F. oxysporum and altered the taxonomic composition of soil bacterial communities. Sixteen bacterial genera were significantly increased from compost in every experiment, potentially playing a role in pathogen suppression. In all experiments, there was a consistent negative effect of compost on functions related to carbohydrate use and a positive effect on bacteria with flagella. Results from this work demonstrate that compost can reduce the abundance of soilborne plant pathogens and raise questions about the role of microbes in plant pathogen suppression.

Facilitating Effects of Reductive Soil Disinfestation on Soil Health and Physiological Properties of Panax ginseng.

Chemical soil fumigation (CSF) and reductive soil disinfestation (RSD) have been proven to be effective agricultural strategies to improve soil quality, restructure microbial communities, and promote plant growth in soil degradation remediation. However, it is still unclear how RSD and CSF ensure soil and plant health by altering fungal communities. Field experiments were conducted to investigate the effects of CSF with chloropicrin, and RSD with animal feces on soil properties, fungal communities and functional composition, and plant physiological characteristics were evaluated. Results showed that RSD and CSF treatment improved soil properties, restructured fungal community composition and structure, enhanced fungal interactions and functions, and facilitated plant growth. There was a significant increase in OM, AN, and AP contents in the soil with both CSF and RSD treatments compared to CK. Meanwhile, compared with CK and CSF, RSD treatment significantly increased biocontrol Chaetomium relative abundance while reducing pathogenic Neonectria relative abundance, indicating that RSD has strong inhibition potential. Furthermore, the microbial network of RSD treatment was more complex and interconnected, and the functions of plant pathogens, and animal pathogen were decreased. Importantly, RSD treatment significantly increased plant SOD, CAT, POD activity, SP, Ca, Zn content, and decreased MDA, ABA, Mg, K, and Fe content. In summary, RSD treatment is more effective than CSF treatment, by stimulating the proliferation of probiotic communities to further enhance soil health and plant disease resistance.

Do Added Microplastics, Native Soil Properties, and Prevailing Climatic Conditions Have Consequences for Carbon and Nitrogen Contents in Soil? A Global Data Synthesis of Pot and Greenhouse Studies.

Microplastics threaten soil ecosystems, strongly influencing carbon (C) and nitrogen (N) contents. Interactions between microplastic properties and climatic and edaphic factors are poorly understood. We conducted a meta-analysis to assess the interactive effects of microplastic properties (type, shape, size, and content), native soil properties (texture, pH, and dissolved organic carbon (DOC)) and climatic factors (precipitation and temperature) on C and N contents in soil. We found that low-density polyethylene reduced total nitrogen (TN) content, whereas biodegradable polylactic acid led to a decrease in soil organic carbon (SOC). Microplastic fragments especially depleted TN, reducing aggregate stability, increasing N-mineralization and leaching, and consequently increasing the soil C/N ratio. Microplastic size affected outcomes; those <200 µm reduced both TN and SOC contents. Mineralization-induced nutrient losses were greatest at microplastic contents between 1 and 2.5% of soil weight. Sandy soils suffered the highest microplastic contamination-induced nutrient depletion. Alkaline soils showed the greatest SOC depletion, suggesting high SOC degradability. In low-DOC soils, microplastic contamination caused 2-fold greater TN depletion than in soils with high DOC. Sites with high precipitation and temperature had greatest decrease in TN and SOC contents. In conclusion, there are complex interactions determining microplastic impacts on soil health. Microplastic contamination always risks soil C and N depletion, but the severity depends on microplastic characteristics, native soil properties, and climatic conditions, with potential exacerbation by greenhouse emission-induced climate change.

Sustainable soil management under drought stress through biochar application: Immobilizing arsenic, ameliorating soil quality, and augmenting plant growth.

Rise in climate change-induced drought occurrences have amplified pollution of metal(loid)s, deteriorated soil quality, and deterred growth of crops. Rice straw-derived biochars (RSB) and cow manure-enriched biochars (CEB) were used in the investigation (at doses of 0%, 2.5%, 5%, and 7.5%) to ameliorate the negative impacts of drought, improve soil fertility, minimize arsenic pollution, replace agro-chemical application, and maximize crop yields. Even in soils exposed to severe droughts, 3 months of RSB and CEB amendment (at 7.5% dose) revealed decreased bulk density (13.7% and 8.9%), and increased cation exchange capacity (6.0% and 6.3%), anion exchange capacity (56.3% and 28.0%), porosity (12.3% and 7.9%), water holding capacity (37.5% and 12.5%), soil respiration (17.8% and 21.8%), and nutrient contents (especially N and P). Additionally, RSB and CEB decreased mobile (30.3% and 35.7%), bio-available (54.7% and 45.3%), and leachable (55.0% and 56.5%) fractions of arsenic. Further, pot experiments with Bengal gram and coriander plants showed enhanced growth (62-188% biomass and 90-277% length) and reduced arsenic accumulation (49-54%) in above ground parts of the plants. Therefore, biochar application was found to improve physico-chemical properties of soil, minimize arsenic contamination, and augment crop growth even in drought-stressed soils. The investigation suggests utilisation of cow manure for eco-friendly fabrication of nutrient-rich CEB, which could eventually promote sustainable agriculture and circular economy. With the increasing need for sustainable agricultural practices, the use of biochar could provide a long-term solution to enhance soil quality, mitigate the effects of climate change, and ensure food security for future generations. Future research should focus on optimizing biochar application across various soil types and climatic conditions, as well as assessing its long-term effectiveness.

Recent advancement of nano-biochar for the remediation of heavy metals and emerging contaminants: Mechanism, adsorption kinetic model, plant growth and development.

Even though researches have shown that biochar can improve soil-health and plant-growth even in harsh environments and get rid of harmful heavy metals and new contaminants, it is still not sustainable, affordable, or effective enough. Therefore, scientists are required to develop nanomaterials in order to preserve numerous aquatic and terrestrial species. The carbonaceous chemical known as nano-biochar (N-BC) can be used to get rid of metal contamination and emerging contaminants. However, techniques to reduce hetero-aggregation and agglomeration of nano-biochar are needed that lead to the emergence of emerging nano-biochar (EN-BC) in order to maximise its capacity for adsorption of nano-biochar. To address concerns in regards to the expanding human population and sustain a healthy community, it is imperative to address the problems associated with toxic heavy metals, emerging contaminants, and other abiotic stressors that are threatening agricultural development. Nano-biochar can provide an effective solution for removal of emerging contaminants, toxic heavy metals, and non-degradable substance. This review provides the detailed functional mechanistic and kinetics of nano-biochar, its effectiveness in promoting plant growth, and soil health under abiotic stress. Nonetheless, this review paper has comprehensively illustrated various adsorption study models that will be employed in future research.

Microplastic contamination in the agricultural soil-mitigation strategies, heavy metals contamination, and impact on human health: a review.

Microplastic pollution has emerged as a critical global environmental issue due to its widespread distribution, persistence, and potential adverse effects on ecosystems and human health. Although research on microplastic pollution in aquatic environments has gained significant attention. However, a limited literature has summarized the impacts of microplastic pollution the agricultural land and human health. Therefore, In the current review, we have discussed how microplastic(s) affect the microorganisms by ingesting the microplastic present in the soil, alternatively affecting the belowground biotic and abiotic components, which further elucidates the negative effects on the above-ground properties of the crops. In addition, the consumption of these crops in the food chain revealed a potential risk to human health throughout the food chain. Moreover, microplastic pollution has the potential to induce a negative impact on agricultural production and food security by altering the physiochemical properties of the soil, microbial population, nutrient cycling, and plant growth and development. Therefore, we discussed in detail the potential hazards caused by microplastic contamination in the soil and through the consumption of food and water by humans in daily intake. Furthermore, further study is urgently required to comprehend how microplastic pollution negatively affects terrestrial ecosystems, particularly agroecosystems which drastically reduces the productivity of the crops. Our review highlights the urgent need for greater awareness, policy interventions, and technological solutions to address the emerging threat of microplastic pollution in soil and plant systems and mitigation strategies to overcome its potential impacts on human health. Based on existing studies, we have pointed out the research gaps and proposed different directions for future research.

Biodegradable plastics: mechanisms of degradation and generated bio microplastic impact on soil health.

Conventional petroleum-derived polymers are valued for their versatility and are widely used, owing to their characteristics such as cost-effectiveness, diverse physical and chemical qualities, lower molecular weight, and easy processability for large-scale production. However, the extensive accumulation of such plastics leads to serious environmental issues. To combat this existing situation, an alternative lies in the production of bioplastics from natural and renewable sources such as plants, animals, microbes, etc. Bioplastics obtained from renewable sources are compostable and susceptible to degradation caused by microbes hydrolyzing to CO2, CH4, and biomass. Also, certain additives are reinforced into the bioplastic films to improve their physicochemical properties and degradation rate. However, on degradation, the bio-microplastic (BM) produced could have positive as well as negative impact on the soil health. This article thus focuses on the degradation of various fossil based as well as bio based biodegradable plastics such as polyhydroxyalkanoates (PHA), polyhydroxy butyrate (PHB), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), and polysaccharide derived bioplastics by mechanical, thermal, photodegradation and microbial approaches. The degradation mechanism of each approach has been discussed in detailed for different bioplastics. How the incorporation or reinforcement of various additives in the biodegradable plastics effects their degradation rates has also been discussed. In addition to that, the impact of generated bio-microplastic on physicochemical properties of soil such as pH, bulk density, carbon, nitrogen content etc. and biological properties such as on genome of native soil microbes and on plant nutritional health have been discussed in detailed.

Evaluating the Soil Quality Index Using Three Methods to Assess Soil Fertility.

Soil health plays a crucial role in crop production, both in terms of quality and quantity, highlighting the importance of effective methods for preserving soil quality to ensure global food security. Soil quality indices (SQIs) have been widely utilized as comprehensive measures of soil function by integrating multiple physical, chemical, and biological soil properties. Traditional SQI analysis involves laborious and costly laboratory analyses, which limits its practicality. To overcome this limitation, our study explores the use of visible near-infrared (vis-NIR) spectroscopy as a rapid and non-destructive alternative for predicting soil properties and SQIs. This study specifically focused on seven soil indicators that contribute to soil fertility, including pH, organic matter (OM), potassium (K), calcium (Ca), magnesium (Mg), available phosphorous (P), and total nitrogen (TN). These properties play key roles in nutrient availability, pH regulation, and soil structure, influencing soil fertility and overall soil health. By utilizing vis-NIR spectroscopy, we were able to accurately predict the soil indicators with good accuracy using the Cubist model (R2 = 0.35-0.93), offering a cost-effective and environmentally friendly alternative to traditional laboratory analyses. Using the seven soil indicators, we looked at three different approaches for calculating and predicting the SQI, including: (1) measured SQI (SQI_m), which is derived from laboratory-measured soil properties; (2) predicted SQI (SQI_p), which is calculated using predicted soil properties from spectral data; and (3) direct prediction of SQI (SQI_dp), The findings demonstrated that SQI_dp exhibited a higher accuracy (R2 = 0.90) in predicting soil quality compared to SQI_p (R2 = 0.23).

Effect of Integrated Nutrient Management on Soil Health, Soil Quality, and Production of Cowpea (Vigna unguiculata L.).

The integrated application of inorganic fertilizers, organic fertilizers, and biofertilizers helps sustain the nutrient pool and benefits the soil quality, thereby boosting plant health. The effect of different combinations of biofertilizers (consortium biofertilizer [CBF]-non-rhizobial PGPR), inorganic fertilizers, and organic fertilizers on soil health, growth, and yield of cowpea was evaluated by conducting a field experiment. The application of N100 FYM + CBF resulted in significantly higher populations of bacteria, fungi, PSB, and diazotroph, as well as soil dehydrogenase and alkaline phosphatase enzyme activities. However, the application of N100 FYM recorded a significantly higher actinomycetes population. The application of N100 FYM + CBF resulted in significantly higher soil OC, available nitrogen, phosphorus, and potassium. The soil pH was recorded to be highest in control, and soil EC was recorded to be lowest in control. The plant uptake of nitrogen, phosphorus, and potassium was significantly higher with N50 FYM + NP50 + CBF. The root-shoot biomass, number of leaves, nodules/plant, number of pods/plants, pod biomass, pod length, and pod width were significantly higher in treatment having N50 FYM + NP50 + CBF. However, the height of the plant, number of branches, and biomass of leaves were highest in treatment with N25 FYM + NP75 + CBF. The pod and stover yield were significantly higher in treatment with N50 FYM + NP50 + CBF. The results showed that the integrated application of non-rhizobial PGPR along with organic and inorganic fertilizer helps to improve overall soil health, quality, and plant growth of forage cowpea contributing to an increase in crop yield.

Machine learning-based soil quality assessment for enhancing environmental monitoring in iron ore mining-impacted ecosystems.

In November 2015, a catastrophic rupture of the Fundão dam in Mariana (Brazil), resulted in extensive socio-economic and environmental repercussions that persist to this day. In response, several reforestation programs were initiated to remediate the impacted regions. However, accurately assessing soil health in these areas is a complex endeavor. This study employs machine learning techniques to predict soil quality indicators that effectively differentiate between the stages of recovery in these areas. For this, a comprehensive set of soil parameters, encompassing 3 biological, 16 chemical, and 3 physical parameters, were evaluated for samples exposed to mining tailings and those unaffected, totaling 81 and 6 samples, respectively, which were evaluated over 2 years. The most robust model was the decision tree with a restriction of fewer levels to simplify the tree structure. In this model, Cation Exchange Capacity (CEC), Microbial Biomass Carbon (MBC), Base Saturation (BS), and Effective Cation Exchange Capacity (eCEC) emerged as the most pivotal factors influencing model fitting. This model achieved an accuracy score of 92% during training and 93% during testing for determining stages of recovery. The model developed in this study has the potential to revolutionize the monitoring efforts conducted by regulatory agencies in these regions. By reducing the number of parameters that necessitate evaluation, this enhanced efficiency promises to expedite recovery monitoring, simultaneously enhancing cost-effectiveness while upholding the analytical rigor of assessments.

Soil quality increases with long-term chabazite-zeolite tuff amendments in arable and perennial cropping systems.

The application of natural zeolites to improve soil quality and functioning has become highly popular, but we still miss information about the long-term effects on the soil due to its application. This study assesses the soil quality index (SQI) of three distinct agricultural soil systems 6-10 years after a single application of natural chabazite zeolite as a soil amendment. These soils exhibit different management practices: intensive arable (cereals), intensive perennial (pear) and organic perennial (olive). In the arable system, a zeolite application dosage of 5, 10 and 15 kg m-2 was tested and compared to unamended soil. In the two perennial systems, an application of 5 kg m-2 was tested against untreated reference sols. A set of 25 soil physical, chemical and biological parameters linked to soil health and quality were analysed at each experimental site. The dataset was investigated through Principal Component Analysis (PCA) to calculate the soil quality index (SQI) using linear scoring. In the arable-cereal field, the SQI doubled (0.3 to ca. 0.6 for all amendments) in chabazite-amended plots; a dose effect was not recognizable. In both perennial fields, the SQI was significantly higher in the chabazite-amended plots (5 kg m-2) with similar increases as compared to the arable-cereal field. At each site, the indicators selected by the PCA were different, indicating that chabazite addition impacted soil quality differently in each cropping system. Overall, the results highlighted a significant increase in soil quality with chabazite amendment, which confirms its potential for increasing soil health in the long-term.

Optimizing sustainable agriculture: A comprehensive review of agronomic practices and their impacts on soil attributes.

This study explores agronomic management (AM) effects on soil parameters under diverse conditions. Investigating tillage practices (TP), nutrient management (NM), crop rotation (CR), organic matter (OM), irrigation management (IM), and mulching (MS), it aims to reveal impacts on soil productivity, nutrient availability, microbial activity, and overall health. Varied TP affect soil quality through compaction, porosity, and erosion risk. Proper NM is vital for nutrient cycling, preventing imbalances and acidification. CR disrupts pest cycles, reduces weed pressure, and boosts nutrient recycling. OM management enhances soil quality by influencing organic carbon, nutrient availability, pH, fertility, and water retention. Optimizing IM regulates soil water content without inducing waterlogging. MS contributes to OM content, nutrient retention, soil structure, and temperature-moisture regulation, benefiting soil biota, aggregation, soil health and agricultural productivity. The review emphasizes integrated nutrient, CR, and OM management's positive impact on fertility and microbial activity. Different TP and IM variations impact soil health and crop production. Judicious implementation of these practices is essential for sustainable agriculture. This synthesis identifies uncertainties and proposes research directions for optimizing productivity while ensuring environmental sustainability. Ongoing inquiry can guide a balanced approach between yields and resilient soil stewardship for future generations.

A systematic benchmarking framework for future assessments of soil health: An example from Denmark.

Based on current evidence and established critical thresholds for soil degradation indicators, it is concerning that over 60-70% of European soils are unhealthy due to unsustainable management and the impact of climate change. Despite European and national efforts to improve soil health, significant gaps remain. The proposal for a Soil Monitoring and Resilience Law, to be implemented by the European Union, seeks to establish a framework for soil monitoring and promote sustainable management practices to achieve healthy soils by 2050. This requires extensive data collection and soil monitoring systems to accurately estimate soil health across Europe, considering the diversity of soil types, climates, and land uses. To establish a framework for soil monitoring, we must understand the site-specific status of soil and the ranges of soil health indicators across specific pedoclimatic regions. In our study, we evaluated the soil status in agricultural areas in Denmark using soil health indicators and a site-specific benchmarking approach. We compiled nationally representative datasets, combining point and model-informed data of soil parameters such as organic carbon content, bulk density, pH, electrical conductivity, clay-to-soil organiccarbon ratio, water erosion, and nitrogen leaching. By categorizing Danish agricultural soils into monitoring units based on textural classes, landscape elements, and wetland types, we calculated benchmarks for these indicators, considering different cropping systems. Our approach provided detailed point-based results and a spatially explicit overview of the status of soil health indicators in Denmark. We identified areas where soil deviates from the benchmarks of different indicators. Such deviations might indicate soil functions operating outside the normal range, posing potential threats to soil health. This proposed framework could support the establishment of a baseline for assessing the directionality of future changes in soil health. Moreover, it is adaptable for implementation by other countries to support assessments of soil health.

Assessment of growth, reproduction, and vermi-remediation potentials of Eisenia fetida on heavy metal exposure.

Heavy metal pollution is a significant environmental concern with detrimental effects on ecosystems and human health, and traditional remediation methods may be costly, energy-intensive, or have limited effectiveness. The current study aims were to investigate the impact of heavy metal toxicity in Eisenia fetida, the growth, reproductive outcomes, and their role in soil remediation. Various concentrations (ranging from 0 to 640 mg per kg of soil) of each heavy metal were incorporated into artificially prepared soil, and vermi-remediation was conducted over a period of 60 days. The study examined the effects of heavy metals on the growth and reproductive capabilities of E. fetida, as well as their impact on the organism through techniques such as FTIR, histology, and comet assay. Atomic absorption spectrometry demonstrated a significant (P < 0.000) reduction in heavy metal concentrations in the soil as a result of E. fetida activity. The order of heavy metal accumulation by E. fetida was found to be Cr > Cd > Pb. Histological analysis revealed a consistent decline in the organism's body condition with increasing concentrations of heavy metals. However, comet assay results indicated that the tested levels of heavy metals did not induce DNA damage in E. fetida. FTIR analysis revealed various functional group peaks, including N-H and O-H groups, CH2 asymmetric stretching, amide I and amide II, C-H bend, carboxylate group, C-H stretch, C-O stretching of sulfoxides, carbohydrates/polysaccharides, disulfide groups, and nitro compounds, with minor shifts indicating the binding or accumulation of heavy metals within E. fetida. Despite heavy metal exposure, no significant detrimental effects were observed, highlighting the potential of E. fetida for sustainable soil remediation. Vermi-remediation with E. fetida represents a novel, sustainable, and cutting-edge technology in environmental cleanup. This study found that E. fetida can serve as a natural and sustainable method for remediating heavy metal-contaminated soils, promising a healthier future for soil.