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Cassava (Manihot esculenta Crantz) is a major staple food in many developing countries, including Brazil. However, it faces significant challenges due to diseases such as dry root rot (DRR) and black root rot (BRR) caused by soil-borne plant pathogenic fungi. This study explored the use of cover crops to suppress these diseases and to improve the agronomic traits of cassava. Over four cultivation cycles, various cover crops (sunn hemp, black oat, jack bean, maize, peanut and cowpea) were alternated with cassava varieties 'BRS Kiriris' (resistant) and 'BRS Formosa' (susceptible) in soil infested with DRR (Fusarium oxysporum, F. equiseti, F. verticillioides, F. solani, F. lateritium, F. chlamydosporum) and BRR (Lasiodiplodia theobramae, Neoscytalidium dimidiatum) pathogens. In the 2nd cycle, only germination showed significant differences, but by the 4th cycle, various agronomic parameters, including fresh weight (FW.AP), dry weight (DW.AP) of the aerial part, fresh weight (FW.Root), dry weight (DW.Root) of the roots, and plant vigor. Cowpea was identified as the most effective cover crop for reducing the disease index (DI %) by promoting healthier and taller cassava plants. Jack beans and peanuts also had positive effects on vigor, FW.AP, DW.AP, FW.root, and DW.root. In contrast, maize, black oats, Crotalaria ochroleuca, cassava, and fallow soils had minimal impacts. Throughout these cycles, the selected cover crops consistently contributed to disease reduction and improved the agronomic performance of the cassava. This study highlights the potential of holistic disease management strategies. [ABSTRACT FROM AUTHOR]

The main objective of the current study was to use seven lots in Hartford, CT that are planned for community reuse to determine the optimal sampling density that allows for the detection of hotspots of lead pollution while limiting the labor of the sampling process. The sampling density was investigated using soil Pb measured by in situ X-ray Fluorescence as the indicator to evaluate soil health, with a new threshold of 200-mg/kg proposed by the USEPA in January of 2024. Even though this study takes place in an urban setting, where the new USEPA policy requires the use of a 100-mg/kg threshold for Pb due to the fact that there are other identifiable sources of the contaminant, only the 200-mg/kg threshold is discussed because it is evident from the analysis that compliance of a 100 mg/kg threshold in urban plots is highly unlikely (five out of seven sites would require complete site excavation prior to reuse). Using the inverse distance weighted geospatial interpolation of in situ pXRF determined lead measurements, grid sampling resolutions of 3-m, 4-m, 5-m, 6-m, 8-m, 10-m, and 12-m were compared. Ultimately, the case study finds that the largest grid resolution that can be implemented for soil screening to maintain hotspots of pollution to properly inform soil management decisions is a 6-m grid, or a density of approximately 1/36-m2. [ABSTRACT FROM AUTHOR]

Intercropping is a prevalent soil management strategy within orchards, whereas it is unclear how inoculation with arbuscular mycorrhizal (AM) fungi and intercropping affect tree growth, soil properties, and rhizosphere metabolite profiles. This study investigated the effects of inoculation with Diversispora spurca and intercropping with hairy vetch (Vicia villosa) on biomass production, soil available nutrients, water-stable aggregate (WSA) distribution, phosphatase activity, and secondary metabolite profiles in walnuts (Juglans regia). The intercropping only elevated soil nitrate N levels and WSA distribution at the 0.5–2 mm size, and also triggered 2159 differential metabolites (1378 up-regulated and 781 down-regulated), with armillaramide as the most prominently up-regulated metabolite, followed by the substance diminished upon D. spurca inoculation. Conversely, D. spurca inoculation increased walnut biomass, WSA distribution across the 0.25 − 2 mm size, and acid and neutral phosphatase activities, as well as triggered 2489 differential metabolites (897 up-regulated and 1592 down-regulated), with pteroside D being highest up-regulated differential metabolite, allowing a competitive advantage to AM plants in combating soil pathogens. Despite significantly suppressing root AM fungal colonization and biomass production in AM walnuts, intercropping significantly increased soil ammonium and nitrate N levels in AM walnuts as well as WSAs at the 1–4 mm size, exhibiting a synergistic effect. Flavone and flavonol biosynthesis and pyruvate metabolism were simultaneously involved following AM inoculation or intercropping. Co-application of AM inoculation and intercropping triggered 1006 differential metabolites, with urocanic acid being the most up-regulated metabolite, although it decreased following AM inoculation, suggesting the involvement of mycorrhizal hyphae in soil histidine uptake. Under intercropping, AM inoculation elicited 418 differential metabolites, with the most up-regulated metabolite being implicated in flavonoid pathways. AM inoculation primarily triggered the biosynthesis of unsaturated fatty acids, regardless of intercropping or not, implying a potential increase in unsaturated fatty acid contents of walnut kernels. It concluded that AM inoculation and intercropping interactively affected walnut growth, soil attributes, and soil microenvironment. [ABSTRACT FROM AUTHOR]

The replacement of farmland by native hygro-plants is increasingly common globally within the context of wetland ecosystem restoration. Understanding the long-term effects of this replacement on the abundance and persistence of soil organic carbon (SOC) in mountain marshes is important for soil carbon management. Here, the restored plateau mountain marshes of Duliu River Wetland Provincial Nature Reserve, China was selected. The properties, soil moisture content (SMC), pH, texture, free-form iron oxides (), amorphous iron oxides (), mineral-associated organic carbon (MAOC), and iron-bound organic carbon (Fe-OC) were analyzed in topsoil samples (0 ~ 20 cm) during the restoration of rice paddies to Sphagnum palustre L. wetlands for 0, 2, 10, and 20 years. Natural Sphagnum wetlands were also used as the control. We found that marsh restoration increased SMC, , , / , SOC, MAOC, Fe-OC, Fe-OC/SOC, but decreased the MAOC/SOC ratio. MAOC/SOC ratio of marshes were expectedly lower than the proportion of labile SOC in total SOC during the restoration period. SMC, SOC, and MAOC were higher in the natural Sphagnum wetlands than in other habitats. Both SOC and Fe-OC/SOC were positively correlated with SMC, , , / , and Fe-OC, but negatively correlated with soil pH. MAOC/SOC was negatively correlated with SMC, and / . These results emphasized the significance of reconverting rice paddies to marsh wetlands for increasing the sequestration of labile SOC and Fe-OC. Further studies are required to identify and quantify the organo-mineral stabilization mechanisms of SOC at the different SOC fractionations throughout the restoration period. [ABSTRACT FROM AUTHOR]

Soil quality is pivotal for crop productivity and the environmental quality of agricultural ecosystems. Achieving sufficient yearly income and long-term farm continuity are key goals for farmers, making sustainable soil management an economic challenge. Existing bio-economic models often inadequately address soil quality. In this study, we apply the novel FARManalytics model, which integrates chemical, physical, and biological indicators of soil quality indicator, quantitative rules on how these indicators respond to farmers' production management over time, and an economic calculation framework that accurately calculates the contribution of production management decisions towards farm income. This is the first study applying this model on existing arable farms. FARManalytics optimizes crop rotation design, cover crops, manure and fertilizer application and crop residue management. Nine Dutch arable farms were analyzed with a high variation in farm size, soil type, and cultivated crops. First, we assessed farm differences in soil quality and farm economics. Second, we optimized production management to maximize farm income while meeting soil quality targets using farm-specific scenarios. Third, we explored the impact of recent policy measures to preserve water quality and to increase the contribution of local protein production. The results show that the case farms already perform well regarding soil quality, with 75% of the soil quality indicators above critical levels. The main soil quality bottlenecks are subsoil compaction and soil organic matter input. We show that even in front-runner farms, bio-economic modeling with FARManalytics substantially improves economic performance while increasing soil quality. We found that farm income could be increased by up to €704 ha−1 year−1 while meeting soil quality targets. Additionally, we show that to anticipate on stricter water quality regulation and market shift for protein crops, FARManalytics is able to provide alternative production management strategies that ensure the highest farm income while preserving soil quality for a set of heterogenous farms. [ABSTRACT FROM AUTHOR]

Purpose: Prediction of soil particle content is essential for soil texture classification, soil management and agricultural production. This study aimed to achieve high-accuracy predictions of soil particle content in the Ogan-Kucha River Oasis using hyperspectral data and environmental variables. Materials and methods: We collected 62 representative surface soil samples (depth: 0–10 cm), and conducting indoor soil particle content and spectral measurements. The relationship between environmental variables and soil particle content was analyzed using the Boruta algorithm, and seven three-band spectral indices (TBIs) were constructed using an optimal band algorithm. By integrating environmental covariates and TBIs, soil particle inversion models were developed using the extreme learning machine (ELM), backpropagation neural networks (BP), neural networks optimized with the sparrow search algorithm (SSA-BP), and neural networks optimized with the sparrow search algorithm enhanced by Sine chaos mapping (Sine-SSA-BP). Results and discussion: The results demonstrated that (1) the Boruta algorithm identified key environmental covariates that affect specific soil particle components; (2) there was significant variation in the correlation between different TBIs and soil particle content, with absolute correlation coefficients ranging from 0.225 to 0.852; (3) the estimation models established by the four machine learning algorithms performed well in predicting soil particle content, particularly for silt (R2: 0.664–0.858, RMSE: 11.107–17.128) and clay (R2: 0.444–0.857, RMSE: 0.550–1.405), for which higher accuracy was achieved; and (4) compared with the traditional ELM (R2: 0.422–0.664), BP (R2: 0.487–0.673) and SSA-BP models (R2: 0.625–0.777), the Sine-SSA-BP model showed a significant improvement in prediction accuracy, with the highest R2 reaching 0.858. Conclusion: Compared to the traditional ELM, BP and SSA-BP models, the Sine-SSA-BP model significantly excelled in predicting soil particle content, offering innovative insights and robust support for soil texture classification and management. [ABSTRACT FROM AUTHOR]

Despite the significant biodiversity in the Cerrado, the process of occupation, subsequent economic cycles, and intensification of agriculture in a predatory manner have caused profound alterations in this biome. This study analyzed changes in land use and land cover in the Cerrado of Mato Grosso do Sul between 1985 and 2022 by mapping and also investigating the formation and dynamics of sand dunes in the Bauru sedimentary basin, focusing on the Pardo River watershed. MapBiomas Network data, collection 8, were used for land use and land cover analysis. Arenization foci cartography was conducted using brightness index 2 based on Sentinel-2 satellite images in Sentinel Application Platform software. The historical analysis of land use and cover in the Cerrado of Mato Grosso do Sul revealed a rapid transformation of the landscape, with a drastic reduction of native vegetation and an intensification of large-scale monocultures. Between 1985 and 2022, the Cerrado of Mato Grosso Sul lost 4.6 million hectares of native vegetation (forest formations, savannahs, grasslands, and wetlands), representing 24.54% of this territory. Recent changes in land use include pasture-soybean and pasture-eucalyptus. In the Pardo River watershed, arenization foci cover an area of 17,834.34 hectares, with varying dimensions ranging from less than 1 hectare to 376.41 hectares. The arenization process occurs in different slope compartments, such as the base, slope, and interfluves. The physical and chemical characteristics of Quartzipsamments, such as low organic carbon content in soil, are associated with high rates of surface exposure and weakened load-dependent structures, leading to degradation. Arenization occurs where natural vegetation has been suppressed and soil has been depleted by poorly managed production processes. [ABSTRACT FROM AUTHOR]

Morphometric analysis is important for conservation and management of watersheds including flood control measures, which is in turn related to topographical components. Prioritization of sub-watersheds based on morphometric factors is carried out to understand the vulnerability of different sub-watersheds to hazards like flooding, soil erosion and groundwater storage. It is carried out in the initial phase so as to enhance the efficacy in selection of water and soil management and remedial practices. In the present study, prioritization is attempted using multi criteria approach based on VIKOR on the sub-watersheds of Mahe river basin in southwest India vis-à-vis their susceptibility to flooding. Thirteen morphometric factors pertaining to twelve sub-watersheds of the river basin are used in the present analysis and they are classified (High, Moderate and Low) based on their risk of flooding. Sub-watersheds 3–8, upstream of the Mahe were identified as being the most prone to flooding. Sub-watersheds 1 and 2, offer a moderate risk of flooding, since the advantage of prominent runoff in their upper reaches is inhibited by the laterite dominated terrain downstream. The sub-basins 9–13 in the coastal plains, forming ~ 60% of total area of Mahe basin, fall in 'Least' category. The prioritization of sub-watersheds based on Multi Criteria Decision Analysis of their morphological factors is found to be useful in the discrimination of flooding prone areas. This would help in the selection of suitable management and remedial measures for the sub-watersheds based on their hazard of flooding. [ABSTRACT FROM AUTHOR]

Biochar and green manure have been widely applied in agricultural production and are important means to achieve sustainable agriculture. However, there is limited research systematically and comprehensively exploring the response of soil microbiota and the changes in soil metabolomics after the addition of two different carbon source amendments to the soil, and the differential mechanisms of soil metabolomics between them remain unclear. In this study, a long-term field experiment (initiated in 2019) was conducted to investigate the effects of biochar and green manure application on soil nutrients and soil functions driven by soil microbes. Compared to the pure fertilizer treatment, biochar increased soil total carbon by 14.54% to 27.04% and soil available potassium by 4.67% to 27.46%. Ryegrass significantly increased soil available phosphorus and organic matter. Under different fertilization regimes, the ecological niches of soil microbes changed significantly. Network analysis revealed that long-term ryegrass returning reduced the complexity of soil microbial networks. Ryegrass and biochar increased dispersal limitation in fungal assemblages (reaching 93.33% and 86.67%, respectively), with biochar particularly enhancing variable selection in bacterial assemblages (accounting for 53.33%). Variation partitioning analysis based on redundancy analysis indicated that humic substances had the highest explanatory power for microbial community variation, with humic substances explaining 38.49% of bacteria and 52.19% of fungi variation. The ryegrass treatment mainly changed the abundance of carbohydrates (CH), amines (AM), c (AH), and lipids (LP), while the BC treatment mainly altered the abundance of organic acids (AC), amines (AM), and carbohydrates (CH). Meanwhile, both treatments significantly reduced the bisphenol A, one of the soil pollutants. Ryegrass incorporation significantly increased the abundance of genes related to soil C, N, P, and S cycling, especially genes involved in carbon decomposition, while biochar significantly enhanced the abundance of nitrogen fixation genes nifH and Hao in soil. Random forest model results indicated that carbohydrates, alcohols, aromatics (AR), and ester (ES) were the main categories of metabolites in soil influenced by differential microbes, and Finegoldia served as a common important metabolic driving species. In summary, this study reveals the processes of soil function, microbial community succession, and metabolism driven by ryegrass and biochar, providing important insights for optimizing soil management and improving soil quality. Highlights: Ryegrass green manure (RG) and biochar (BC) induced the simplification of microbial networks and an increase in fungi's random assembly processes. RG promoted denitrification and carbon degradation functional genes, while BC enhanced nitrogen fixation genes. RG accelerated soil energy flow by promoting M00307 and M00061. In RG-treated soil, the main metabolites were Carbohydrates, while in BC-treated soil, the main metabolites were Acids and Amines. Both treatments reduced soil pollutant bisphenol A. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) plays a vital role in maintaining or enhancing soil fertility and quality of paddy field, but there is still limited information about how SOC mineralization responds to different tillage managements under the double-cropping rice (Oryza sativa L.) system in southern of China. Therefore, this study was designed to explore the changes in SOC content, soil enzyme activities (invertase, cellulose and urease), SOC mineralization at 0–10 cm and 10–20 cm layers and its relationship with 7-years tillage management under the double-cropping rice system of southern China. The experiment included four tillage managements: rotary tillage with all residues removed as a control (RTO), conventional tillage with residue incorporation (CT), rotary tillage with residue incorporation (RT), and no-tillage with residue retention (NT). The results indicated that SOC and soil labile organic carbon contents at 0–10 cm and 10–20 cm layers in paddy field with CT and RT treatments were significantly higher than the RTO treatment. Compared to the RTO treatment, SOC mineralization and accumulation at 0–10 cm and 10–20 cm layers in paddy field with CT, RT and NT treatments were increased. SOC accumulation and potential mineralization at 0–10 cm layer with NT treatment were significantly higher than the CT, RT and RTO treatments. Soil mineralization constant at 10–20 cm layer with CT treatment was significantly higher than those of RT, NT and RTO treatments. This result indicated SOC mineralization rate and accumulation at 10–20 cm layer of CT, RT, NT and RTO treatments were lower than those of treatments at 0–10 cm layer. Compared to RTO treatment, soil invertase, cellulose and urease activities with CT and RT treatments were significantly increased. Compared to RTO treatment, soil invertase, cellulose and urease activities at 0–20 cm layer of CT treatment increased by 22.6%, 46.2% and 89.0%, respectively. There was significantly positive correlation between SOC accumulation and SOC content, soil invertase, cellulose, urease activities, but SOC accumulation was significantly negative correlated with soil pH, bulk density. Therefore, CT and RT treatments were beneficial managements to improve SOC content and SOC mineralization in the double-cropping rice field of southern China. [ABSTRACT FROM AUTHOR]

To reduce the C footprint of human activities, there is a growing need for alternative energy sources including the production of bioenergy feedstocks. Miscanthus × giganteus is a high yielding grass with low environmental impact and high potential for feedstock use. Studying the composition of the aboveground tissues of Miscanthus is important for understanding feedstock quality for biofuel conversion and how crop residue quality may affect soil input management. Data on Miscanthus leaf and stem chemistry including carbon (C), nitrogen (N), macronutrient concentrations, and the optical characteristics of the water extractable organic matter (WEOM) was analyzed to identify differences in composition between aboveground tissues and modeled to identify soil variables that may be correlated with tissue chemistry. Leaves and stems were dominated by N, potassium (K), calcium (Ca), phosphorus (P), and magnesium (Mg), but overall, the leaves contained higher nutrient concentrations compared to the stems. The leaves displayed elevated Si:K (0.0935) and Ca:K (0.445) ratios and lower C:N (36) and C:P (323) ratios compared to the stems (0.0560, 0.145, 150, and 645, respectively). Leaf WEOM contained large, aromatic, and complex structures, while the stem WEOM was dominated by small, recently produced structures. Varying relationships were found between tissue C and the mobile C pool in surface (0–15 cm) and deep (45–60 cm) soils. Overall, Miscanthus leaves had a chemical composition indicative of reduced biofuel quality compared to the stems. The relationships with soil mobile C suggest a dynamic linkage between Miscanthus physiology and this active soil C pool. These results have implications for crop nutrient allocation and nutrient management practices. [ABSTRACT FROM AUTHOR]

Assessing soil quality (SQ) post-land use changes is crucial for sustainable land and soil management. This study was conducted in the Fereydan region, Isfahan province, Iran. One hundred soil samples were collected from irrigated croplands, dry land farms, and pasture lands to form the total data set (TDS). Eighteen soil properties were assessed using three soil quality indicators (SQI): additive (SQIa), weighted additive (SQIw), and Nemoro (SQIn). Principal component analysis (PCA) identified six key parameters to construct a minimum data set (MDS), including clay, soil organic matter (SOM), total nitrogen (TN), available phosphorus (P), mean weight diameter of soil aggregates (MWD), and reference bulk density (BDref). The studied area is classified according to soil quality metric as follows: 2.78% very good, 11.11% good, 41.67% medium, 25.00% poor, and 19.44% very poor, indicating an overall moderate soil quality. Linear relationships analysis between TDS and MDS for SQIa-L, SQIa-NL, SQIw-L, SQIw-NL, SQIn-L, and SQIn-NL showed R2 values of 0.61, 0.58, 0.79, 0.67, 0.59, and 0.52, respectively. SQIw-L provided a better estimation, suggesting that using MDS with a linear approach and weighted additive indexing saves time and reduces expenses. These findings have practical applications in managing soil quality in hilly regions and similar agroecological areas, contributing to sustainable agriculture practices and resource conservation. [ABSTRACT FROM AUTHOR]

The small particle size of nanoplastics allows them to migrate through soil and make them highly bioavailable, posing a potential threat to groundwater. Measures are urgently needed to reduce the migration of nanoplastics in soil. However, there is limited research available on this topic. In this study, two types of iron-modified biochar (magnetic corncob biochar (MCCBC) and magnetic walnut shell biochar (MWSBC)) were selected and their effects on the transport of polyvinyl chloride nanoplastics (PVC-NPs) in natural sandy soil columns under different ionic types and strengths were investigated. The results show that the transport of PVC-NPs in single sandy soil columns was rapid and efficient, with the estimated breakthrough rate of 85.10%. However, the presence of MCCBC and MWSBC (0.5%, w/w) significantly inhibited the transport of PVC-NPs in sandy soil columns (p < 0.05), and MCCBC had a stronger inhibitory effect on the transport of PVC-NPs than MWSBC. This can be attributed to the fact that the adsorption of PVC-NPs on adsorbents followed the order as: MCCBC > MWSBC > sandy soil. The retention of PVC-NPs by MCCBC and MWSBC is determined by ionic type and ionic strength. The presence of coexisting ions enhanced the inhibitory effect of iron-modified biochar on the transport of PVC-NPs, with the following order: Ca2+ > SO2- 4 > Cl− > NO- 3. The inhibitory effect of MCCBC and MWSBC on the transport of PVC-NPs in soil columns increased with increasing ionic strengths. Furthermore, MCCBC and MWSBC inhibited the migration of PVC-NPs in a rainwater-soil system. The mechanisms by which MCCBC and MWSBC affect the transport of PVC-NPs in soil columns were considered to enhancing adsorption and decreasing soil pore volume. The results provide new insights into the management of soil nanoplastic pollution. [ABSTRACT FROM AUTHOR]

Soil fertility depletion presents a negative feedback mechanism that could have impacted early adopters of agriculture. We consider whether such feedback can lead to population cycles among early agriculturalists, such as the boom-and-bust patterns suggested by an increasing amount of evidence for Neolithic Europe. Using general mathematical arguments, we show that this is unlikely, due to the interplay of two factors. First, there is an important mathematical difference between biotic (i.e., logistic) and abiotic resource replenishment; soil nutrients are better modeled by the abiotic case, which leads to more stable dynamics. Second, under realistic conditions, the resource replenishment process operates on fast time scales compared to attainable population growth rates, reinforcing the tendency towards stable dynamics. Both these factors are relevant for early agricultural societies and imply that nutrient depletion is likely not the main contributing factor to boom-and-bust cycles observed in the archaeological record. [ABSTRACT FROM AUTHOR]

This study focuses on the potential quantity of soil lead (Pb) remediation in a typical karst region of China, an area where previous research on the potential remediation quantity of Pb in soil has been scarce. In this study, 12,547 surface soil samples and 54 sets of soil-profile samples were collected. This analysis investigated the sources, concentrations, distribution, and reserve properties of soil Pb in the study region. Building upon these findings, a formula for calculating the potential remediation quantity of Pb in karst soils was derived. The results disclose variations in Pb content within the surface soil, with values spanning from 9.4 to 376.4 mg/kg and a background level of 72.97 mg/kg. Additionally, the Pb content in deep soil shows a spectrum from 1.6 to 160.9 mg/kg. Principal component analysis showed that the sources of Pb in karst soil were related to the geological background, agricultural fertilization, and mineral resources. Single-factor variance analysis demonstrated significant influences of topography, parent rock type, soil utilization, and soil type on soil Pb content. The spatial distribution of soil Pb, as determined by principal component analysis, was influenced by mineral distribution, geological background, and agricultural fertilization. The soil profile analysis showed that Pb concentrations followed a logarithmic distribution pattern with increasing depth. A formula for the potential remediation quantity of Pb was derived using a logarithmic model. This rational and representative formula establishes a foundation for the management of Pb-influenced soils in karst regions. [ABSTRACT FROM AUTHOR]

Background and aims: Forest management practices affect soil carbon dynamics, particularly by changing the diversity of aboveground plant functional groups. However, we have a limited understanding of the underlying mechanisms for how plant management affects soil respiration in planted forest ecosystems. Methods: We conducted a 3-year manipulation experiment of plant functional groups that included understory removal, tree root trenching, and fertilization treatments in 2-year-old and 6-year-old Eucalyptus plantations in the subtropical region, to explore the responses of soil carbon emission and microbial community composition. Results: Soil respiration was significantly suppressed by understory removal (-38%), tree root trenching (-41%), and their interactions (-54%), but fertilization alone and in interactions had no significant effect. Soil bacterial and fungal diversity was negatively affected by understory removal and tree root trenching, respectively. Soil respiration and microbial diversity were lower in younger plantations. Reductions in soil carbon emissions were associated with losses of plant functional groups and soil microbial diversity, while increases in soil respiration were associated with soil physicochemical factors, soil temperature, and plantation age. Conclusions: The results indicated that understory removal and tree root trenching strongly affected soil respiration, while the power effects were regulated by soil microbial community and soil properties in contrast plantation ages. Our findings highlight that plant management is of great significance to the soil carbon emission processes in afforested plantations. [ABSTRACT FROM AUTHOR]

Aims: Management can largely influence the sustainability and functionality of forest plantations. However, the role of biogas-slurry and biochar application in supporting soil's multifunctionality during afforestation remains poorly understood. Methods: We conducted a six-year field experiment to examine the responses of soil ecosystem multifunctionality (EMF) to the application of biogas-slurry applied annually as four treatments, and a single initial application of four treatments of biochar in a new poplar plantation based on a reclaimed coastal area. The EMF was calculated as the standardized average of multiple soil surrogates of soil functions linked with C, N, and P cycles. Results: Both biogas-slurry and biochar had significantly positive effects on EMF and individual functions, with biogas-slurry having the strongest positive effect, thus promoting carbon stocks and nutrient availability. Furthermore, interactions between biochar and biogas-slurry produced a substantial synergistic effect on soil multifunctionality. The application of biogas-slurry significantly and directly increased the C, N, and P cycle multifunctionality (CCMF, NCMF, and PCMF, respectively). In contrast, a single application of biochar profoundly increased the CCMF but decreased the NCMF, thus requiring a trade-off of multiple elements of soil multifunctionality. Conclusions: We show that organic management has the potential to boost multiple ecosystem functions during afforestation. These findings further highlight the importance of rational fertilization strategies for long-term forest management. [ABSTRACT FROM AUTHOR]

It is well known that long-term chemicalised agricultural practices harmfully affect soil health and prevent sustainable management of fertility in crop fields, including that of plantation crops. Accordingly, an investigation was carried out to check how soil fertility characteristics such as soil pH, soil mineral nutrient and organic carbon content are altered in long-term chemicalised rubber plantations of Kerala, located in the ecologically sensitive Western Ghats of South India. Soil fertility status concerning soil types in the Rubber fields (USDA soil orders - suborders) such as Inceptisols - Oxic Dystrudepts (IOD), Ultisols - Ustic Haplohumults (UUH), Ultisols - Typic Kandiustults (UTK) and Mollisols - Pachic Argiustolls (MPA) involving six soil series are critically analysed. A negative impact of long-term chemicalised agriculture was visible in low soil pH and nutrient levels. In general, rubber fields in the region, even in the generally alkaline Mollisols, showed a pH of 6.23. The soils showed reduced nutrient and carbon content and a comparatively poor soil fertility index specific to soil types. The soil available NPK and soil total cations were found to be comparatively low and soil specific. However, rubber fields in Mollisols were significantly higher in STK, STMg, STCa, and STNa while those in Ultisols were significantly higher in SAP and SAK than other soil orders. The Inceptisols were significantly higher in SAN, STP, and soil organic carbon than others. Therefore, balanced fertilizer application concerning soil types per proper soil fertility monitoring has become significant to sustainable soil productivity management in rubber plantations. [ABSTRACT FROM AUTHOR]

Nutrient management in coffee-based agroforestry systems plays a critical role in soil nitrogen (N) cycling, but has not been well documented. The objective of this study was to evaluate the effect of coffee canopy management and fertilization on soil N dynamics. This study used a randomized complete block design (2 × 3 × 2) with four replications. There were three factors: 1) coffee canopy management (T1: Pruned, T2: Unpruned), 2) fertilizer type (O: Organic, I: Inorganic; M: 50% Organic + 50% Inorganic), and 3) fertilizer dose (D1: low, D2: medium, D3: high). Soil N dynamic indicators (i.e., total N, ammonium (NH4+), nitrate (NO3−), net N-NH4+, net N-NO3−, soil microbial biomass N) were measured at two soil sampling depths (0–20 cm and 20–40 cm). Results showed that pruning increased soil total N and microbial biomass N (MBN) by 10–56% relative to unpruned coffee trees. In contrast, the unpruned coffee canopy had 15–345% higher NH4+, NO3−, net N-NH4+, net N-NO3−, and microbial biomass N concentration than pruned coffee. Mixed fertilizer application increased NO3− and net N-NH4+ accumulation by 5–15% relative to inorganic and organic fertilizers. In addition, medium to high dose fertilization led to a 19–86% higher net N-NO3− concentration and microbial biomass N as compared to low dose fertilization. The treatment of no pruning and mixed fertilizer at low to medium doses was the optimal management strategy to maintain soil available N, while pruning combined with organic fertilizer has the potential to improve soil total N and MBN. [ABSTRACT FROM AUTHOR]

Wildfires are complex natural phenomena that exert significant impacts on landscapes, societies, and economies. Understanding the concept of resilience is crucial in mitigating its possible negative impacts, as it involves preparing for, responding to, and recovering from wildfires. This research aims to demonstrate the utility of in situ soil profile description in assessing land use resilience using an Analytic Hierarchy Process (AHP) through an expert panel survey. The study examines a catchment located in the Balearic Islands, considering two fire occurrences (once and twice), comparing abandoned agricultural terraces and natural hillslopes. The results demonstrated that the priority ranking of variables to assess soil profile resilience against wildfires, determined by a panel of 10 experts, identified horizon depth (25.1%), slope inclination (21.5%), and hydrological connectivity (16.6%) as the most crucial factors. Other variables, such as number and size of roots, structure of pedal soil material, size class structure, and rock fragments, also contributed to resilience but to a lesser extent, with scores ranging from 5.7% to 9.6%. Analyzing the priorities established by the experts using AHP, the results showed that the least resilient soil horizon was H1 of the control hillslope, especially under high and low connectivity processes, which aligned with the loss of superficial soil horizons after one and two wildfires. Hillslopes showed greater changes in resilience after occurring wildfires compared to terraces, with the most significant alterations occurring after the second wildfire event. This study addresses a significant knowledge gap in the field by highlighting the interconnectedness of wildfires, resilience, and land use, providing insights into land management strategies for wildfire-prone regions. [ABSTRACT FROM AUTHOR]

Collapsing erosion is a unique phenomenon commonly observed on the granite residue hillslopes in the tropical and subtropical regions of southern China, characterized by its abrupt occurrence and significant erosion volumes. However, the impacts of soil crust conditions on the erosion of colluvial deposits with granite residual soils have only been studied to a limited extent. To address this issue, this study investigates the impacts of three soil crust conditions (i.e., without crust, 10-minute crust, and 20-minute crust) on gully morphology, rainfall infiltration, and runoff and sediment yield during slope erosion of colluvial deposits with granite residues (classified as Acrisols) in Yudu County, Ganzhou City, Jiangxi Province, China, using simulated rainfall tests and photographic methods. The results showed that as the strength of the soil crust increased, the capacity of moisture infiltration and the width and depth of the gully as well as the sediment concentration and yield ratio decreased; at the same time, the runoff ratio increased. The sediment yield in the without-crust test was found to be 1.24 and 1.43 times higher than that observed in the 10-minute crust and 20-minute crust tests, respectively. These results indicate that soil crusts can effectively prevent slope erosion and moisture infiltration, while providing valuable insights for the management of soil erosion in natural environments. [ABSTRACT FROM AUTHOR]

Purpose: The influence of tropical fruticulture that was established in Amazonian dark earth was investigated by considering changes in soil physical and chemical properties. Soil samples were collected at two layers (0–0.1 and 0.1–0.2 m) under two dissimilar conditions: naturalized archaeological site (Amazonian dark earth) vs. tropical fruticulture. Material and methods: We evaluated soil texture (clay, sand, and silt contents), bulk density, soil porosity, soil resistance, carbon stock (C stock), soil moisture, geometric mean diameter, weighted average diameter, average diameter < 2 mm, average diameter > 2 mm, soil pH, exchangeable cations (Al3+, Ca2+, Mg2+, K+), potential acidity, soil organic carbon (SOC), and available P. Results and discussion: Our results emphasized the soil physico-chemical changes as influenced by tropical fruticulture in the Amazonian dark earth. The PCA and SEM showed that the tropical fruticulture had an overall negative effect on available P, Ca2+, GMD, soil aggregation, SOC, C stock, bulk density, and soil resistance. Conclusion: The results of our study highlighted the importance of considering the Amazonian dark earth as an archaeological site, and when necessary for food production, we must consider soil management practices to promote soil ecosystem avoiding soil quality loss. Thus, long-term experiments in the studied sites considering soil management may exploit different feedback among tropical fruticulture and the Amazonian dark earth. [ABSTRACT FROM AUTHOR]

The conversion of farmland to forest in China has been recognized for its positive impact on above-ground vegetation and carbon sequestration. However, the impact on soil quality during land conversion, particularly in vulnerable karst areas, has received less attention. In this study conducted in a karst area of southwest China, eight different farmland conversion strategies were investigated to assess improvements in surface soil carbon, nitrogen, and ecosystem multi-functionality (EMF). Our results showed that farmland converted to afforestation areas or farmland that was abandoned contained higher amounts of carbon (total, organic, active) and ammonium nitrogen (NH4+-N) in the soil compared to farmland converted to grassland or maize crop. Soluble organic carbon levels were higher in afforestation and grassland areas compared to maize crop controls. By contrast, soil from grassland and abandoned land exhibited higher levels of nitrate nitrogen (NO3--N) compared to afforestation land or maize crop controls. There were no differences in NH4+-N content between any condition, except for afforestation land that specifically contained the Zenia insignis plant species. Afforestation land consistently exhibited higher EMF values than grassland. Pearson correlation analysis revealed positive relationships between soil indices and EMF scores, except for NO3--N.Random forest analysis explained 95% of the variation in soil EMF and identified specific soil factors: total carbon, organic carbon, active labile organic carbon, total nitrogen, and ammonium nitrogen, as the main drivers of soil multi-functionality. Our studies show how various reforestation strategies can enhance soil nutrient sequestration and improve soil multi-functionality of farmland in the karst areas.These findings provide insight into sustainable soil management practices for converting farmland into natural areas. [ABSTRACT FROM AUTHOR]

Efficient utilization of agricultural soil phosphorus (P) and mitigation of loss risks necessitate a precise evaluation of soil P storage capacity (SPSC). This study compared the effectiveness of four soil test P methods (Oxalate, Bray, Olsen, and Mehlich-1) to accurately estimate SPSC and simplify P loss risk assessment of soils located in a typical red soil in the Sunjia Watershed, Yingtan, Jiangxi Province, China. The extraction efficiencies of these methods for Fe, Al, P, and P saturation ratio (PSR) were compared, and conversion equations between SPSCOx (extracted using Oxalate) and soil test P (Bray, Olsen, and Mehlich-1) were derived through fitting analysis. The results underscored Oxalate as the optimal extractant for gauging P loss risk in red soils. Structural equation modeling (SEM) unveiled the substantial impact of amorphous iron-aluminum oxides (Feo, Alo) on SPSC, with Feo exerting a more pronounced influence than Alo. Among soil physicochemical properties, total carbon emerged as the most influential, and a strong interaction was noted between the physicochemical properties and Feo and Alo. The study delineated three crucial P concentration ranges for practical P management in red soils. When Bray-P < 48.2 mg kg–1, the soil acted as a P sink with no P loss risk, allowing for continued P application to augment crop yield. Conversely, within 48.2 mg kg–1 < Bray-P ≤ 55.2 mg kg–1, the soil attained its maximum secure P capacity; further P application significantly escalated the peril of P loss. Subsequently, when Bray-P > 55.2 mg kg–1, the soil turns into a source of P release. This signifies an escalated risk of P loss, demanding the immediate implementation of environmental protective measures. [ABSTRACT FROM AUTHOR]

This study presents a pioneering approach that combines artificial intelligence and laser-induced breakdown spectroscopy (LIBS) to predict soil moisture content (MC). The traditional laboratory-based method of MC measurement, involving soil weight comparison before and after heating, is time-consuming, labor-intensive, and prone to low accuracy. In this work, we propose a non-destructive soil MC measurement technique utilizing robust nonlinear models based on LIBS-derived elemental intensities. Support vector regression (SVR) and AdaBoost-based SVR models (SVR-ADB), employing Gaussian Kernel and input features from LIBS data, were employed for MC prediction. Model performance was assessed using standard metrics such as root mean square error, mean absolute error, Nash–Sutcliffe efficiency (NSE), and correlation coefficient (CC) between predicted and actual moisture content. The study employed 485 datapoints generated in our laboratory. An advanced feature optimization technique based on the correlation between the soil MC and the descriptors was employed to select relevant mineral elements as input features. Three feature combinations (Combo-1, Combo-2, and Combo-3) were evaluated to identify the most effective configurations for accurate soil MC predictions. SVR-ADB-3 (Combo-3) demonstrated the highest prediction efficiency in the testing phase, achieving an impressive CC of 0.9998 and NSE of 0.9997. Consistently, Combo-3 outperformed other configurations, emphasizing the importance of the selected features. Validation of the developed models on soils treated with cement and lime stabilizers, whose data were not used during model calibration and verification, confirmed the generalization capability of the models. This study provides valuable insights for policymakers and industry stakeholders, facilitating optimized soil moisture management practices. [ABSTRACT FROM AUTHOR]

The issue of soil acidification in tea plantations has become a critical concern due to its potential impact on tea quality and plant health. Understanding the factors contributing to soil acidification is essential for implementing effective soil management strategies in tea-growing regions. In this study, a field study was conducted to investigate the effects of tea plantations on soil acidification and the associated acid–base buffering capacity (pHBC). We assessed acidification, pHBC, nutrient concentrations, and cation contents in the top 0–20 cm layer of soil across forty tea gardens of varying stand ages (0–5, 5–10, 10–20, and 20–40 years old) in Anji County, Zhejiang Province, China. The results revealed evident soil acidification due to tea plantation activities, with the lowest soil pH observed in tea gardens aged 10–20 and 20–40 years. Higher levels of soil organic matter (SOM), total nitrogen (TN), Olsen phosphorus (Olsen-P), available iron (Fe), and exchangeable hydrogen (H+) were notably recorded in 10–20 and 20–40 years old tea garden soils, suggesting an increased risk of soil acidification with prolonged tea cultivation. Furthermore, prolonged tea cultivation correlated with increased pHBC, which amplified with tea stand ages. The investigation of the relationship between soil pHBC and various parameters highlighted significant influences from soil pH, SOM, cation exchange capacity, TN, available potassium, Olsen-P, exchangeable acids (including H+ and aluminum), available Fe, and available zinc. Consequently, these findings underscore a substantial risk of soil acidification in tea gardens within the monitored region, with SOM and TN content being key driving factors influencing pHBC. [ABSTRACT FROM AUTHOR]

Soil pH is a most of importance for food security with both quantity and quality due to it affect directly or indirectly soil various element supplies. The understanding knowledge about soil pH controlling geochemical components availability and its retention in soil are favor to permanent development of agriculture and then human surviving. Based on the substantial geological data surveyed from 2015 to 2020 in Jiangshan city, China, the present work analysed the relationship between soil pH with 0.5 unit interval and 35 geochemical components, and possible mechanisms were discussed. Soil pH showed negligible effect on the soil organic carbon within the pH range of agricultural production, but negative correlattion with soil organic carbon as pH < 4.5 or > 8.0 due to corresponding substantial accumulation or degradation. The total concentration of elements which dominated by organic-components (e.g. N, P, S) varying with soil pH was similar to organic carbon. The change patterns for other element storages with soil pH increasing exhibited: (1) dropping firstly and then increasing with a "V" shaped for Cr, Ni, Co, I and V; (2) falling after rising appeared a "inverted-V" shape for Pb, Cd, Hg, As, Cu, Zn, Se, and F; (3) keeping a stable level after undergoing a short decrease with a "L" shaped for S, Fe2O3 and Al2O3; (4) retaining a flat level after an increase presented a "inverted-L" shape for Mn, Mo, K, SiO2 and B; (5) almost gradually and linearly increasing for basic oxides (CaO, MgO and Na2O) and few changing for Ge. For the availability of part elements, the optimum soil pHwere 5.0–5.5 for N, 6.5–7.0 for P and Cu, 7.5–8.0 for K and Mo, 7.0–7.5 for Zn, and 5.0–6.0 for B, respectively, expect for the effect of strong acid (pH < 4.0) on N, P, and K. The change of various soil components with soil pH were governed by known factors, such as, ionic properties, oxides adsorption, affinity for organic compounds, and pH dependent formation and solubility of complexes. However, the change of some components with soil pH increasing was difficultly explained by known mechanism, indicating the great complex of natural environments, in where the occurrence of some uncertain factors maybe influenced these components. Nonetheless, the abundant information found in this work is also beneficial to agricultural soil management of farmers, marking policies of departments, and further detailed study of researchers. [ABSTRACT FROM AUTHOR]

Black wattle is a tree native to Australia and commercially planted in South Africa and Brazil. Replacement of exported nutrients by wood and bark harvesting, associated with the maintenance of harvest residues, increases productivity, thus maintaining production sustainability. Here, we review recent advances in soil nutrient dynamics, harvest residue management (HRM), and soil organic matter in black wattle plantations. Over the 7–11-year cycle of black wattle, N is the most exported macronutrient (458–1509 kg ha− 1), followed by K (200–766 kg ha− 1), Ca (270–717 kg ha− 1), Mg (62–128 kg ha− 1), S (29–57 kg ha− 1) and P (16–40 kg ha− 1). The average increase in bark yield to 20 kg P ha− 1 applications on sandy soils was 2.7–2.9 t ha− 1 and on clay soils from 2.8 to 8.7 t ha− 1. Sandy soils with low K are more responsive to fertilizer, and rates must consider the K content and cation exchange capacity. Ca and Mg addition responses are more likely when in the topsoil they are in low concentrations (< 0.75 and 0.41 cmolc dm− 3, respectively). Micronutrient fertilization reduces the occurrence of gummosis caused by Phytophthora spp, and B deficiency is the most common and can be supplied by fertilization or foliar application (1 g B L− 1). Few studies have evaluated the impact of black wattle HRM on soil organic matter (SOM) and its effects on production. However, conserving SOM should be considered an essential practice for the sustainability of black wattle production. [ABSTRACT FROM AUTHOR]

Choosing appropriate tillage methods and applying the right amount of chemical fertilizers are pivotal for optimizing wheat management and enhancing wheat quality. This study investigated the influence of conservation agriculture and phosphorus levels on nutrient content, yield components, and quality traits of wheat in a corn-wheat rotation. Conducted over five years in field conditions, the study employed a randomized complete block design with tillage treatments (conventional tillage, CT; minimum tillage, MT; and no tillage, NT) and phosphorus levels (no fertilizer use, P0; and 100% fertilizer recommendation, PR) as factors. Soil samples were collected during the fourth year (2021–2022). Results revealed significant impacts of tillage methods and phosphorus levels on wheat straw and grain nutrient composition, yield components, and quality traits. Conventional tillage yielded the highest values for protein content (12%), Zeleny sedimentation volume (20.33 mL), hardness index (45), water absorption (64.12%), and wet gluten content (25.83%). Additionally, phosphorus fertilizer application positively influenced protein percentage, gluten weight, and gluten index. The study highlights the potential of strategic soil management, particularly conventional tillage combined with phosphorus fertilization, to enhance wheat quality and yield. By elucidating these relationships, the findings contribute to optimizing wheat cultivation practices and advancing the development of superior wheat cultivars for baking applications. [ABSTRACT FROM AUTHOR]

In line with EU recommendations, the potential 'mining revival' in France focuses on (re)opening mines. In this context, political discussions on post-mining areas have increased, driven by past mismanagements. Scientists are key in these regions, studying contamination, advising policy, and seeking solutions. Based on a case study of phytoremediation research in Saint-Laurent-Le Minier, we explore how lay and expert knowledge intersect. By examining what is hidden and by whom, we unveil research practices and stakeholder dynamics, sparking reflection on the research process while promoting a reflexive approach for researchers. We show research and its application spotlight specific topics (such as soil contamination), select, and make visible certain lay knowledge and local stakeholders and visibilises certain technological choices. [ABSTRACT FROM AUTHOR]

Green manure represents a crucial soil management practice for soil traits and potentially sequestering organic carbon (OC) within the soil profile. Understanding the biomass dynamics of Fabaceae and Poaceae plants has become essential for refining existing models of soil fertility and organic carbon. In this work, we have developed six models of the fertility and carbon stock of the soil collected from the plots where ten plant species were cultivated as green manuring crop. Two of them are named aboveground and belowground biomass models which use specific biomass production parameters α and adapted to both Fabaceae and Poaceae stands, and three other models are named Ca2+, K+ and P models adapted to green manure stands. The last one is named soil organic carbon stock model, and it is adapted to both Fabaceae and Poaceae stands. A Bayesian inference was carried out to determine parameters values according to the 6-years field experiment database. The highest significant values for SOC stock, aboveground biomass model, and belowground biomass modes were found for the Fabaceae model with 9.99 t ha−1, 5.37 t ha−1, and 0.61 g cm−3, respectively. All proposed models into this study (density, soil, and biomass models) were explained by the geometric reliability index (GRI) and efficiency factor (EF) with a more dispersive fitting. This study underscores the importance of considering adapted models from the Fabaceae and Poaceae families, particularly those with high growth rate index (GRI) and efficiency factor (EF). We found that shoot dry biomass exhibited a polynomial decrease, whereas root density showed an exponential decrease over time for both Poaceae and Fabaceae plants. Furthermore, our study revealed that long-term cultivation of cover crops with green manure significantly augmented the contents of exchangeable cations (Ca2+ and K+) as well as soil organic carbon (SOC) stock. Highlights: 1. The green manure practice may increase Ca2+, K+, and soil organic carbon stock in a tropical Regosol. 2. The practice of green manure may enhance soil fertility through consecutive use, resulting in significant impacts on the contents of soil calcium (Ca2+) and potassium (K+). 3. By altering soil fertility both Poaceae and Fabaceae plants used as green manure may promote their own growth by increasing soil organic carbon stock. [ABSTRACT FROM AUTHOR]

Crop yield has been analyzed under different hydrological conditions by many researchers. However, little information is available about the behavior of rice yield for different conditions during its growth. This study investigated the behavior of rice yield under varying hydrological conditions in two regions of India, one rainfed and the other irrigated, for the period 2000–2018. Additionally, it examined how individual, coincidental, and sequential compound extremes, such as rainfall, temperature, and soil moisture, affected rice yield. Four individual, two coincidental, and two sequential compound extremes regression models were developed. These models were designed with yield as a function of individual and compound extremes. Individual extreme models focused on heat and water metrics independently, while compound extremes occurred when heat and water stress coincided or followed each other closely. Linear panel models were used to assess the dependency of rice yield on hydrological parameters. Results indicate that excessive heat negatively affects rice yield, particularly when coupled with low soil moisture. However, excess soil moisture mitigates heat-related damage, highlighting the significance of controlling soil moisture levels. Additionally, coincidental compound extremes pose greater threats to rice yield than sequential ones. The study underscores the importance of considering geographical variations and hydrological variables in understanding crop yield behaviour. Overall, the findings suggest the potential for optimizing soil moisture management to enhance rice yield amidst changing climatic conditions. [ABSTRACT FROM AUTHOR]

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10−4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals. [ABSTRACT FROM AUTHOR]

The Mediterranean region is facing major challenges for soil conservation and sustainable agriculture. Conservation agriculture (CA), including reduced soil disturbance, can help conserve soils and improve soil fertility, but its adoption in the Mediterranean region is limited. Examining farmers' perceptions of soil and underlying sociocultural factors can help shed light on adoption of soil management practices. In this paper, we conducted a survey with 590 farmers across Morocco, Spain and Tunisia to explore concepts that are cognitively associated with soil and perceptions of tillage. We also evaluated differences in perceptions of innovation, community, adaptive capacity, and responsibility for soil. We found that farmers' cognitive associations with soil show awareness of soil as a living resource, go beyond agriculture and livelihoods to reveal cultural ties, and link to multiple levels of human needs. Beliefs about the benefits of tillage for water availability and yield persist among the surveyed farmers. We found that openness towards innovation, perceived adaptive capacity and responsibility for soil were associated with minimum tillage, whereas community integration was not. Education, age and farm lifestyle were also associated with differences in these perceptions. CA promotion in the Mediterranean should emphasize the multiple values of soil, should demonstrate how sufficient yields may be achieved alongside resilience to drought, and be tailored to differing levels of environmental awareness and economic needs across north and south. [ABSTRACT FROM AUTHOR]

Active soil organic carbon (SOC) fractions are major driving factors of soil fertility. Understanding the effects of water and fertilizer management on changes in active SOC fractions helps improve soil quality and maintain high agricultural productivity. We conducted a 3-year field experiment in Northeast China. In this experiment, natural soil (CKT) was used as a blank, and two irrigation regimes were established: conventional flooded irrigation (FI) and controlled irrigation (CI). Four nitrogen application levels were set for both irrigation regimes under deep placement of basal fertilizer N: Nd0 (0 kg ha–1), Nd (110 kg ha–1), Nd1 (99 kg ha–1), and Nd2 (88 kg ha–1). After 3 years, at similar N fertilizer application rate, the rice yield, total organic carbon (TOC), and active SOC fraction content of CI were higher under CI than FI. The growth rate of rice yield was 3.8% − 8.63% under CI than FI. Under CI, the rice yield, active SOC fractions contents and carbon pool management index (CPMI) did not decrease with decreasing N application rate but instead reached the highest level in the CNd1 treatment. Overall, CI with Nd1 treatment appears to be the best practice for improving soil fertility and crop productivity in Northeast China. [ABSTRACT FROM AUTHOR]

Adoption of the farming systems that aim to sequester carbon in agricultural soils is one of the ways to mitigate global climate change. This study focuses on the estimation of organic carbon sequestration potential of the Russian croplands in the upper (0–30 cm) soil layer by creating a set of maps using the data from global and national databases as the input data. The maps are generated within the FAO Global Soil Organic Carbon Sequestration Potential Map (GSOCseq) project according to the unified methodology using the RothC model to predict the rate of carbon sequestration in 2020–2040 under a business as usual scenario (BAU), as well as under sustainable soil management scenarios with additional different C input (+5, +10, and +20%) resulting from the use of sustainable soil management (SSM) scenarios. The total potential sequestration rate by the croplands of the Russian Federation in the 0–30-cm layer under a BAU scenario is assessed at 8.5 Mt/year and the estimate under SSM scenarios, up to 25.5 Mt/year. The carbon sequestration by the cropland of each soil ecological zone (except for the light chestnut (Eutric Cambisols (Protocalcic)) and brown semidesert (Luvic Calcisols) soils, where it is around zero) and on a national scale is positive. The Altai krai, Omsk oblast, Novosibirsk oblast, and Krasnoyarsk krai have the greatest potential for sequestration. Several subjects of the Russian Federation—Krasnodar krai, Republic of Crimea, Rostov oblast, Primorskii krai, Republic of Adygea, and Kaliningrad oblast—demand the adoption of sustainable management of soil resources. [ABSTRACT FROM AUTHOR]

When used as organic amendment, both livestock manure and crop residue can improve soil fertility. However, application of livestock manure alone may cause excessive accumulation of nitrate, and application of crop residue alone may lead to available N deficiency. Therefore, chicken manure was combined applied with rice husk to balance N supply and demand in this study. Greenhouse tomato was grown for three consecutive seasons. Chicken manure and rice husk were applied alone or together at 1:4 or 1:2 mass ratio. The contents of NO3--N and NH4+-N in the topsoil and their distribution in the subsoil were investigated, soil physical properties were analyzed, and tomato yield was recorded. The organic amendments were also incubated in the field to investigate their N release characteristics. Application of chicken manure alone resulted in high soil available N supply, higher tomato yield, and high NO3--N accumulation in the subsoil, whereas application of rice husk alone led to low soil available N supply, low yield, and low NO3--N accumulation in the subsoil. The combined application of chicken manure and rice husk at 1:2 ratios achieved the highest tomato yield with low subsoil NO3--N accumulation. Soil physical properties, such as water retention, were better in the rice husk-added treatments than in the treatment applied only with chicken manure. Combined application of chicken manure and rice husk optimized soil available N management and created a better soil physical environment, thus increasing tomato yield and reducing NO3--N leaching risk as well. [ABSTRACT FROM AUTHOR]

Phytophthora root rot is a major problem for avocado growers around the world. This review summarises the current control measures and their impact on the soil microbiome. The fungicide phosphite is widely used in the avocado industry, and reports from several countries indicate that Phytophthora cinnamomi is developing resistance. For this reason, alternative control measures have been investigated. Applying organic mulches and soil dressings of calcium or silicon provides a level of control. Biological control through the application of suppressive microbes has been actively investigated over many years, but reports of successful field deployment are rare. This review examines the effects on the soil microbiome of these control measures and assesses the future directions for research. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet Plateau, located at the Third Pole and known as the "Asian water tower," serves as a crucial ecological barrier for China. Grasping the soil quality on the Qinghai-Tibet Plateau holds paramount importance for the rational and scientific exploitation of soil resources within the region and is essential for vegetation restoration and ecological reconstruction. This study, conducted in Maqin County, Qinghai Province, collected 1647 soil samples (0–20 cm) within a study area of 6300 km2. Sixteen soil indicators were selected that were split into beneficial (N, P, S, and B), harmful (Cr, Hg, As, Pb, Ni, and Cd), and essential (Cu, Zn, Se, Ga, K, and Ca) elements. The Soil Quality Index (SQI) was computed to assess soil quality across diverse geological contexts, land cover classifications, and soil profiles. The results indicate that the overall SQI in the study area was comparatively high, with most regions having an SQI between 0.4 and 0.6, categorized as moderately to highly satisfactory. Among the different geological backgrounds, the highest SQI was found in the Quaternary alluvium (0.555) and the lowest in the Precambrian Jinshuikou Formation (0.481). Regarding different land-use types, the highest SQI was observed in glacier- and snow-covered areas (0.582) and the lowest in other types of grassland (0.461). The highest SQI was recorded in typical alpine meadow soil (0.521) and the lowest in leached brown soil (0.460). The evaluation results have significant reference value for the sustainable utilization and management of soil in Maqin County, Qinghai Province, China. [ABSTRACT FROM AUTHOR]

Antibiotics in agricultural soil can be accumulated in crops and might pose a potential risk to human health. Nevertheless, there is a lack of knowledge about the impact of nitrogen fertilizers on the dissipation and uptake of antibiotics in soils. Therefore, our aim in this study is to investigate the effects of urea fertilizer on the residues of ciprofloxacin and its uptake by Chinese flowering cabbage (Brassica parachinensis L.) as affected by the associated changes on the soil microbial community. A pot experiment has been conducted using spiked soil with 20 mg ciprofloxacin /kg soil and fertilized with urea at dosages equal to 0, 0.2, 0.4, 0.8 t/ha. Application urea especially at 0.4 t/ha decreased the residue of ciprofloxacin in the soil and its uptake by the roots and its translocation to the shoots of Chinese flowering cabbage. The translocation factors (TFs) for ciprofloxacin were significantly decreased (P < 0.05) only at the treatment of 0.4 t/ha, while no significant difference of bio-concentration factors (BCFs). The average well color development (AWCD) values, Shannon diversity, and richness index were higher in the fertilized than the un-fertilized soils, and all such indicators were greater at the treatment of 0.4 t/ha than at 0.2 and 0.8 t/ha. The carbon substrate utilization of phenolic acids at the treatments of 0.4 t/ha were greater than with other levels of urea fertilizer. In conclusion, moderate urea addition significantly increased soil microbial activity and abundance, which in turn promoted the ciprofloxacin dissipation in soil and plant tissue. The present study provides an economical and operational strategy for the remediation of ciprofloxacin contaminated soils. [ABSTRACT FROM AUTHOR]

The primary objective of this study was to develop soil quality indexes (SQIs) to reveal the changes in SQ during the restoration of vegetation in the reclaimed waste dumps of the Hequ open-pit coal mine. The study built an SQI evaluation model for waste dumps based on the soil management assessment framework. The total data set (TDS) consisted of nine physicochemical property indicators. The selection of the minimum data set (MDS) involved the utilization of principal component analysis (PCA) and Norm values. The SQ was comprehensively evaluated for nine indicators, taking into account the non-linear membership function and the improved Nemerow index. The findings suggested a notable disparity in the SQ between the reclaimed area and the unreclaimed area, yet the overall SQ fell short. In the TDS index system, the organic matter has the highest weight and a greater contribution to the soil quality of the waste dumps. In the MDS indicator system, the weights of organic matter and total nitrogen are both 0.5. According to Nemerow index method, the average SQIN of 5 plots is calculated to be 0.4352 ± 0.194. The average value obtained from TDS is 0.581 ± 0.236, and the average value obtained from MDS is 0.602 ± 0.351. The weighted additive method was employed to compute three SQIs, all of which yielded satisfactory outcomes. And the above evaluation methods indicate that the overall soil quality level of the waste dumps is at a moderate level. The sequence of SQ in various waste dumps was as follows: No.4lower > No.1 > No.2 > No.3 > No.4upper. Specifically, the non-linear membership function indicated that pH, available nitrogen (AN), available phosphorus (AP), surface moisture content (SMC), and bulk density (BD) were crucial in limiting SQIs in total waste dumps. The crucial limiting SQIs in unreclaimed areas were total phosphorus (TP) and total nitrogen (TN). This analysis demonstrates its efficacy in formulating strategies for the SQ evaluation and targeted soil reclamation plans of waste dumps. [ABSTRACT FROM AUTHOR]

Predicted climate warming and prolonged droughts pose a threat to the soil structure as organic carbon losses weaken the stability of soil aggregates. Well-structured soils are important for storage and movement of water, solutes, and air, the development of plant roots, as habitat for soil organisms, and the microbial activity. Structural stability is measured in terms of hydro-mechanical properties. This study compares effects of amorphous silica with those of organic carbon on stability parameters during drying of aggregates from relatively finer- and coarser-textured soils. Silica amendment enhanced the positive effect of organic carbon on structural stability in terms of the tensile strength. Synergistic effects between silica and organic carbon in soil colloids appear to dynamically alter aggregate density and friability (i.e., ability to crumble) during drying. Silica together with organic carbon could help soil management to reduce negative effects of predicted prolonged droughts on soil structure and stability. [ABSTRACT FROM AUTHOR]

This study aims to assess soil organic matter (SOM) humification and changes in molecular structures of humic acids (HAs) induced by long term management practices over soil profile under arid climate in south-eastern Tunisia. Two experimental fields were studied: the first was cultivated with olive tree and tilled for long term (CT) while the second was uncultivated without any management practices and with native vegetation (NC). Soil samples were collected at different depths from (CT) and (NC) profiles to determine chemical properties. Humic acids were isolated and studied by measuring UV-visible ratios (E465/665, E280/664 and E472/664) and fluorescence spectroscopy analysis. Results showed that long-term tillage practices reduced the SOM amount, aromatic condensation, molecular size and humification degree in surface layer of CT confirmed by the decrease in the fluorescence emission areas and UV-visible ratios. Inversely, in deep layers, results showed a greatly humified organic matter and aromatic structures condensation in CT. Long-term tillage leads to a significant decrease in aromatic condensation and OM humification in surface layers. Unmanaged soils provided a favorable environment to maintain OM chemical structures and restore soil quality under long-term management practices. [ABSTRACT FROM AUTHOR]

Background and aims: Monitoring temporal trends in soil properties under rice paddy ecosystems is key for efficient soil management interventions toward sustainable and climate-smart rice production. The objectives of this study were to thoroughly investigate the temporal variations of measured soil properties and evaluate the changes in carbon stocks and soil fertility over a 12-year period under intensively managed rice paddy fields. Methods: A total of 2110 sampling points in paddy rice fields under the same agronomic management were identified. Composite soil samples from the topsoil (0 – 15 cm depth) were collected from each sampling point in each sampling year (2007, 2011, 2015, and 2019) and comprehensively analysed. Results: After 12 years of intensive rice cultivation, soil organic matter significantly increased from 25 g kg−1 to 29.3 g kg−1, with an annual rate of change of 0.33 – 0.34 g kg−1. Within the 12-year period, available phosphorus significantly increased from 130.87 to 140.80 mg kg−1, with a rate of change of 0.83 – 0.95 mg kg−1 year−1. The C stocks increased in the subsequent years with a relative change ratio of 0.94 and 3.91% in 2015 and 2019, respectively. Conclusion: In a span of 12 years, intensive rice cultivation resulted in an increase in soil fertility. Among the identified soil factors, soil pH, organic carbon, exchangeable calcium, and available silicate were positively associated with soil fertility improvement. This study is crucial for the development of sustainable soil management interventions and climate-smart agricultural systems in intensively cultivated rice paddy ecosystems. [ABSTRACT FROM AUTHOR]

We evaluated the farmer's local knowledge and perceptions of sustainable cocoa agroforestry and sustainable soil carbon management in Ghana and Côte d'Ivoire using a social survey research methodology. We employed in-depth interviewing and focus group discussions to solicit information from identified key stakeholders in the cocoa supply chain focusing on the perception of sustainable cocoa agroforestry and soil carbon management. Our results revealed that about 83% and 50.5% of smallholder cocoa farmers from Côte d'Ivoire and Ghana respectively practiced agroforestry on their farms. The respondents, however, had limited knowledge about the term agroforestry and were also not very much aware of soil carbon management. Also, about 53% and 22% of the respondents from Côte d'Ivoire and Ghana perceived agroforestry practice as better than practicing cocoa monoculture. The results further revealed that most of the cocoa farmers in these study areas had limited knowledge of the approaches or strategies to achieve sustainable cocoa agroforestry and soil carbon management on their farms. At the same time, the industry's stakeholders had different perceptions about the approaches or strategies to achieve these. Our results also revealed that educational level was the only socio-economic factor that influenced the farmer's awareness of agroforestry and soil organic carbon. This study thus suggests the need for appropriate training and education for smallholder cocoa farmers, and harmonization of the understanding among different stakeholder groups along the cocoa supply chain of common strategies to adopt to achieve sustainable cocoa production that addresses low productivity, biodiversity loss and carbon emission within the smallholder cocoa production system in West Africa. [ABSTRACT FROM AUTHOR]

In arid and semi-arid regions of China, effective irrigation management and agronomic strategies are essential for enhancing the soil water environment and optimizing water productivity. A three-year (2020–2022) field experiment was conducted in the Ningxia Water Saving Agriculture Science and Technology Park, a semi-arid region in northwest China, to assess the impact of planting patterns, watermelon irrigation quotas and their interaction on soil moisture status, yield and quality. The experiment encompassed: (1) two planting patterns: Apple-watermelon agroforestry and watermelon sole-cropping; and (2) three irrigation quotas (W1: 105 mm, W2: 210 mm, and W3: 315 mm). As the years progress, there is a decreasing trend in the average soil water content (SWC) of the 0–100 cm soil layer within the agroforestry system. During the flowering and fruit setting stage and expansion stage in 2022, the soil water content (SWC) in the agroforestry planting pattern is significantly lower than that in the watermelon sole-cropping pattern. Within the agroforestry planting pattern, the W1 and W2 irrigation quotas increase the average fruit weight, soluble solids content, and sugar content but reduce watermelon yield. The interaction between the W3 irrigation quota and agroforestry planting pattern promotes leaf photosynthesis, and extends the watermelon fruit expansion stage and maturity stage to compensate for the decrease in yield. In summary, the agroforestry planting pattern improves the quality of watermelon fruit, increases soil water utilization, and reduces yield. For those seeking sustainable solutions to enhance land productivity and water use efficiency, apple-watermelon agroforestry emerges as a more promising alternative. [ABSTRACT FROM AUTHOR]

Soil temperature plays a critical role in many soil functions, particularly in arid ecosystems, but is scarcely reported as potential indicator of climate change. Although studies have been conducted worldwide to investigate (both measurements and modeling) temperature changes in the soil profile in response to ambient temperature, no information on soil temperature is available in the state of Kuwait. Hydrological and many bio-geochemical processes are more sensitive to soil temperature than air temperature. In this study, we used observed soil temperature data (2007–2016) from three sites with three soil depth increments (5, 50, 100 cm) and compared to regional climate and regression models' output. The most salient finding of this study is the tight association between observed and simulated soil temperature at shallower soil depths from both the regional climate model (RegCM4) and linear regression model. The RegCM4 model poorly predicted (underestimated) soil temperature at deeper soil layers relative to shallower soil layers. Application of the linear scaling (LS) method has significantly improved the RegCM4 model performance with respect to measured soil temperature, which allows an accurate evaluation of the impact of climate change on the soil temperature under different soil management systems. These findings indicate that RegCM4 can be applied as a reliable predictor of soil temperature under arid ecosystems for which there is a gap in site data availability. [ABSTRACT FROM AUTHOR]

Soil is one of the largest reservoirs of microbial diversity in nature. Although soil management is vital for agricultural purposes, intensive practices can have a significant impact on fertility, microbial community, and resistome. Thus, the aim of this study was to evaluate the effects of an intensive soil management system on the chemical attributes, composition and structure of prevalent bacterial communities, and presence and abundance of antimicrobial resistance genes (ARGs). The chemical characterization, bacterial diversity and relative abundance of ARGs were evaluated in soils from areas of intensive vegetable cultivation and forests. Results indicate that levels of nutrients and heavy metals were higher in soil samples from cultivated areas. Similarly, greater enrichment and diversity of bacterial genera was detected in agricultural areas. Of the 18 target ARGs evaluated, seven were detected in studied soils. The oprD gene exhibited the highest abundance among the studied genes and was the only one that showed a significantly different prevalence between areas. The oprD gene was identified only from soil of the cultivated areas. The blaSFO, erm(36), oprD and van genes, in addition to the pH, showed greater correlation with in soil of cultivated areas, which in turn exhibited higher contents of nutrients. Thus, in addition to changes in chemical attributes and in the microbial community of the soil, intensive agricultural cultivation systems cause a modification of its resistome, reinforcing the importance of the study of antimicrobial resistance in a One Health approach. [ABSTRACT FROM AUTHOR]

Investigating the mineralogical compositions of soils under different geological formations becomes imperative for maximizing agricultural productivity and ensuring the long-term viability of agricultural practices. Therefore, studies were carried out on mineral compositions and diversities of soils developed over the Basement complex rock, Coastal plain sands and Ewekoro formations in Ogun state Nigeria. A total of nine profile pits (three per location) of 2 m × 1 m × 2 m size were dug in all the three locations. Soil samples were collected from the pedogenic horizons of each profile pits in replicates into a well labeled polyethylene bag. Using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) the mineral contents and their relative abundance, elemental compositions and morphologies of the fine sand, coarse silt and clay fractions of the soils at different topographic positions were identified, described and compared. Results obtained from XRD and SEM analyses exhibited similarities. The most abundant elements in the basement complex and Ewekoro pedon were oxygen, carbon and silicon whereas in the coastal plain sand pedon, oxygen, carbon and aluminum were the most abundant element. The presence of mixed-layer illite, mica, kaolinite, quartz, hematite, anatase, goethite, and chlorite at varying degrees was observed in the pedons developed on these geological formations, although kaolinite and quartz dominated the soil matrix. The mineralogical complexity of the pedons followed the order of basement complex > coastal plain sand > Ewekoro formation. Profiles developed on the Ewekoro formation exhibited the highest degree of weathering, as evidenced by their chemical properties and mineralogical compositions. The petrographic evaluation of the three geological formations revealed that all pedons were rich in quartz and exhibited varying degrees of mineral complexity and maturation. The overlapping and distinct characteristics among the geologies indicated different stages of weathering. By using the mineral maturity index, profiles developed over the basement complex rock and the coastal plain sand could be regarded as sub-matured and this could have contributed significantly to the native fertility of these soils and profiles from the Ewekoro formation were the most weathered. The use of Ewekoro formation for agriculture would necessitate significant investments in agro-inputs and sound principles of soil management through integrated soil fertility management. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbon (PHC) contamination is a widespread and severe environmental issue affecting many countries' resource sectors. PHCs are mixtures of hydrocarbon compounds with varying molar masses that naturally attenuate at different rates. Lighter fractions attenuate first, followed by medium-molar-mass constituents, while larger molecules remain for longer periods. This results in significant regulatory challenges concerning residual hydrocarbons in long-term contaminated soils. This study examined the potential risks associated with residual PHC and its implications for risk-based management of heavily contaminated soils (23,000–26,000 mg PHC/kg). Ecotoxicological properties, such as seedling emergence and growth of two native plant species—small Flinders grass (Iseilema membranaceum) and ruby saltbush (Enchylaena tomentosa)—and earthworm survival tests in PHC-contaminated soils, were assessed. Additionally, the effects of aging on the attenuation of PHC in contaminated soils were evaluated. Toxicity responses of plant growth parameters were determined as no-observed-effect concentrations: 75%–100% for seedling emergence, < 25%–75% for plant shoot height, and 75%–100% for earthworm survival. After 42 weeks of aging, the total PHC levels in weathered soils decreased by 14% to 30% and by 67% in diesel-spiked soil due to natural attenuation. Dehydrogenase enzyme activity in soils increased during the initial aging period. Furthermore, a clear shift of bacterial communities was observed in the soils following aging, including enrichment of PHC-resistant and -utilizing bacteria—for example, Nocardia sp. This study underscores the potential of natural attenuation for eco-friendly and cost-effective soil management, underlining that its success depends on site-specific factors like water content and nutrient availability. Therefore, we recommend detailed soil assessments to evaluate these conditions prior to adopting a risk-based management approach. [ABSTRACT FROM AUTHOR]