Mineral fertilizers have sustained food security for decades, yet the long-term impacts on soil microbial communities underpinning soil health remain virtually unknown. We combine standardized field surveys with a meta-analysis to assemble a global dataset of 501 long-term agricultural experiments (≥5 years, median duration 25 years) to evaluate the impacts of sustained mineral fertilization on soil properties and microbial communities. Long-term mineral fertilization increases soil organic carbon by 14% and decreases soil pH by 0.31 units on average relative to unfertilized controls. Soil organic carbon accumulation largely explains increased microbial biomass carbon and living bacterial biomass. Mineral fertilizer-induced acidification primarily reshapes dominant bacterial taxa, with the relative abundance of Proteobacteria increasing and Firmicutes declining, whereas fungal community composition remains stable. Virulent bacteriophages increase in association with shifts in bacterial hosts. Microbial activities reveal a decoupling of more nitrogen- and phosphorus-acquisition enzymes from the unchanged production of carbon-mineralization enzymes. Microbial communities are taxonomically reorganized without reducing richness or promoting fungal pathogens. These responses are evaluated in the context of agroecosystem type, fertilization regime, and cropping regime. Our findings provide global-scale evidence for the consequences of long-term mineral fertilization on soil health, which is integral to guiding fertilizer management for sustainable agriculture.

The drilosphere, which includes the earthworm body and earthworm-worked soil, is an anoxic hotspot for denitrification that produces nitrous oxide (N2O) as a reaction intermediate and dinitrogen (N2) as the final product. The objective was to document the diversity and activity of denitrifying bacteria in the drilosphere of the earthworm Lumbricus terrestris. Drilosphere components included live earthworms, gut homogenate, fresh and aged casts, middens and burrow lining, with bulk soil from the same field as a control. Denitrifier community in drilosphere components and bulk soil was evaluated by extracting genomic DNA and targeting the nosZ amplicon sequences with 454 pyrosequencing, and basal denitrification rates were determined with the acetylene block assay. Pyrosequencing detected 39 representative OTUs associated with Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and uncultured bacteria. Of these, 20 OTUs were unique to the drilosphere, with 70 % of the nosZ sequences found only in the gut homogenate, several of which belong to an undescribed phylogenetic clade, suggesting a novel group of endemic denitrifiers in the gut of L. terrestris. Basal denitrification rates ranged from 2.67 to 0.07 μg (N2O + N2)-N g soil-1h−1 and ranked as: live earthworms ≥ fresh casts ≥ burrow lining ≥ middens = aged casts ≥ bulk soil ≥ gut homogenate (p < 0.05, Fisher’s LSD test). Complete denitrification in L. terrestris and its drilosphere produced more N2 than N2O. Distinctive nosZ sequences in the gut of L. terrestris point to a clade with different N2O reduction potential than the denitrifiers in the L. terrestris drilosphere and bulk soil.

Trait-mediated interactions across trophic levels drive trophic cascades in macroecological systems, yet their relevance in microbially dominated soil ecosystems remains underexplored. We combined a regional field survey with controlled experiments using a defined 122-strain synthetic bacterial community and bacterivorous nematodes to test whether faunal predation reorganizes root-associated microbiomes to suppress soilborne disease. Field observations showed that sites with stronger nematode-Pseudomonadota associations had lower bacterial wilt incidence. In controlled experiments, nematode predation selectively enriched Pseudomonadota in the rhizosphere and reduced Ralstonia solanacearum populations and disease incidence. Preferential grazing drove this enrichment: Pseudomonadota constituted over 95% of sequences in nematode guts, and focal taxa showed moderate antagonism, small cell size, and high metabolic activity. Together, these results identify Pseudomonadota as key bridging taxa in cross-trophic interactions. Trait-linked responses to predation contribute to pathogen suppression and suggest a biocontrol framework that integrates microbial traits with trophic connectivity.

The grand challenge for sustainable farming systems is to maintain agricultural productivity in a changing climate with water resource constraints. Here, we present a spatiotemporal footprint framework to optimize agricultural activities in winter wheat systems, based on a 30-year integrated assessment from 1991 to 2020 in China. During this period, agricultural activities in China's winter wheat production system emitted 66.6 x 106 t CO2eq yr-1 and consumed 112 x 109 m3 yr-1 of water annually. The Huang-Huai-Hai Plain had high greenhouse gas emissions and water consumption, yet maintained relatively low product-level footprints. From 2001 to 2020, synergistic reductions in carbon and water footprints were achieved by optimizing fertilizer practices for yield improvement. Scenario-based mitigation analysis revealed that substituting organic alternatives for chemical fertilizers reduced emissions by 12 %, while powering irrigation equipment with renewable energy lowered emissions by 7.0 %, and improving irrigation efficiency reduced water consumption by 3 %, relative to the baseline scenario. Together, precision fertilization and energy-efficient irrigation were highly impactful, reducing carbon emissions by up to 20 % and being a practical strategy to enhance food security and environmental sustainability.

Deep straw incorporation increases carbon (C) inputs in the soil profile of agroecosystems, but the long-term effects on this practice on crop yield and soil organic carbon (SOC) sequestration remain to be quantified. We compared a novel method to achieve deep burial of maize straw (Alternating-furrow Stratified Straw Deep Burial method) with traditional straw mulching in a 14-year maize field experiment in northeast China. Using 1 3C stable isotope tracing, we tracked the migration, and transformation of straw carbon in the soil profile. Under field conditions, the straw deep burial method released more dissolved organic carbon (DOC) from straw carbon, leading to greater mineral-associated organic carbon (MAOC) formation in the 20-60 cm subsoil. At 150 d after adding the straw, the straw deep burial method significantly increased straw-derived MAOC stocks in the 20-40 cm (107%) and 40-60 cm (322%) compared with straw mulching, building a more stable carbon reservoir. In contrast, straw mulching tended to lose MAOC from the 20-60 cm subsoil, potentially due to decomposition activated by rhizodeposits. Crucially, the gain in SOC sequestration was directly linked to an increase in maize yield. Straw return significantly increased maize yield compared to no straw return, with deep burial being the most effective method, yielding 8.2% more than straw mulching. Our study reveals the dual benefits of straw deep burial for SOC sequestration and crop productivity in sustainable maize agroecosystems.

BACKGROUND AND AIMS:Nitrate (NO3-) uptake is primarily driven by soil water flow and varies among maize root types. This study quantified NO3- uptake by embryonic (primary and seminal) and crown roots under contrasting soil water conditions to determine their relative contributions to total plant N acquisition during early vegetative growth. METHODS:Maize was grown in a split-root pot that segregated the embryonic and crown roots. The sandy-loam soil was moistened to water potentials of either -5 kPa (wet) or -30 kPa (relatively dry). A partial N mass balance was made by destructively sampling shoots, roots, and soils after 0, 24, and 48 h following 15N-KNO3 injection at the V3 (three-leaf) and V6 (six-leaf) stages. Root hydraulic conductance was quantified using an osmotic-driven root exudation method. Gross nitrification was assessed using a 15N isotope dilution technique. KEY RESULTS:At the V3 stage, crown roots had 202% more N uptake than embryonic roots in wet soil (-5 kPa). However, in relatively dry soil (-30 kPa), N uptake was similar for embryonic and crown roots, and crown root hydraulic conductance was 80% lower than in wet soil. By the V6 stage, crown roots dominated N uptake, with embryonic roots supplying < 20% of N uptake. Gross nitrification rates did not differ significantly between root types. CONCLUSIONS:Maize NO3- uptake depends primarily on the crown roots, due to their capacity to extract water and NO3- from soil, even under dry conditions.

Biodegradable plastic mulches (BPMs) are effective in moderating climate change and water shortage impacts on rice production. A three-year field experiment in Northeast China assessed the performance of BPMs-based on rice productivity, greenhouse gas (GHG) emissions and the synchronization index of water-saving and carbon mitigation. The BPMs-based control irrigation (MCI) and continuous flooding (MCF) enhanced grain yield by 9% and 16%, while reducing CH4 emissions by 42% and 15%, global warming potential by 39% and 14%, and GHG intensity by 44% and 25%, compared with traditional continuous flooding. BPMs used less irrigation water (MCI: 34%; MCF: 19%) and had better water productivity (MCI: 21%; MCF: 33%), resulting in greater net profit (MCI: 10%; MCF: 32%) than the rice with traditional continuous flooding. With GHG mitigation, it also reflected in an improved synchronization index, with MCI being superior in this regard than MCF. Thus combining BPMs with water-saving irrigation holds promise for lowering water consumption and climate impacts, whilst supporting higher grain yields and economic benefits in sustainable rice productivity.

Organic substrates from plants and animals are crucial for sustainable agriculture, yet their effects on agroecosystem multifunctionality remain underexplored at the global scale. Using a meta-analysis of 8509 field observations, we examined how plant-based carbon inputs (legume cover crops) and animal-based carbon inputs (vermicompost) influence nine ecological functions. Both carbon inputs significantly improved agroecosystem multifunctionality, with legume cover crops increasing it by 17% and vermicompost by 31%. These improvements were concentrated in supporting and provisioning services. Soil biota abundance was strongly linked to multifunctionality and showed more frequent win-win relationships with other functions than species richness. Across agroecosystems, soil biota abundance was primarily associated with local soil properties, followed by climate factors. Our findings highlight soil biota abundance as a community attribute complementary to species richness that contributes to agroecosystem multifunctionality. We further propose site-specific management strategies that align plant- and animal-based carbon inputs with local environmental conditions in global croplands to enhance multifunctionality.

Management improves the growth and fruit yield of cultivated lowbush blueberries, but it remains to be seen how the pruning method, fertilizers, and fungicide applications affect soil fertility. This study investigates the impact of pruning, fungicide, and fertilization management practices on key soil parameters related to soil fertility, namely: soil organic matter (SOM) content, soil pH, nitrogen and phosphorus mineralization, nitrification, and phosphorus saturation index (PSI). A split-split-plot experiment was established, including two pruning methods (mechanical and thermal), two fungicide regimes (with or without), and three types of fertilizer applications (mineral, organic, or none). Mineral fertilizer applications significantly and strongly affected most soil fertility indicators, with increased nitrogen (+77 kg ha(-1)) and phosphorus (+117 kg ha(-1)) mineralization and SOM (+34 g kg(-1)), while reducing soil pH (-0.18) and nitrification (-46 kg ha(-1)). Thermal pruning decreased nitrification (-26 kg ha(-1)), soil pH (-0.12), and SOM concentration (-29 g kg(-1)). Fungicide applications showed no significant impact on soil fertility. While mineral fertilizer improves soil fertility, repeated application of organic fertilizer increases soil pH (+0.34), nitrification (+53 kg ha(-1)), phosphorus mineralization (+161 kg ha(-1)), and the soil phosphorus saturation index at undesirable levels (PSI > 2.8%) in lowbush blueberry production systems. The loss of SOM with thermal pruning is noteworthy and highlights the management impact and need for regular monitoring to maintain soil fertility in such fields.

Plant litter, the dominant source of soil organic carbon (SOC), enters as aboveground plant residues or belowground as rhizodeposition, forming hotspots of microbial SOC formation within the detritusphere and rhizosphere. The knowledge of microbial metabolism in these two hotspots help to reconcile much of the debate and contradictory evidence about litter effects on SOC stabilization. To investigate how rhizosphere-detritusphere interactions impact SOC formation, we quantified the particulate organic C (POC) and mineral-associated organic C (MAOC) pools in a field experiment receiving aboveground litter additions from six plant species varying in their litter quality. Rhizosphere effects, defined here as the activity around living roots compared to the soil with decomposing litter (detritusphere), on microbial biomass and activity increased with decreasing litter quality (high C:N ratio), reflecting a strategy in which plant roots acquire nutrients through interactions with rhizosphere microbes. Low-quality (high C:N) litter decreased the POC content in rhizosphere by 21 % but raised the MAOC content by 17 % relative to detritusphere, increasing the MAOC portion in SOC by 13 %. The rhizosphere effect on POC and MAOC pools was absent when high-quality (low C:N) litter was applied, presumably because the microbially-mediated nutrient release by mineralization matched the plant demands. These results indicate that rhizosphere effect contributed to more stable SOC than corresponding detritusphere under low-quality litter inputs, partly due to the efficient MAOC formation by rhizosphere microorganisms. Consequently, the interactive effects between rhizosphere and detritusphere on SOC pools crucially depend on litter traits, directing soil microbial efficiency and nutrient cycling.

Every year, soil microbial-mediated hydrogen (H2) oxidation removes about 80 % of the global atmospheric H2, an indirect greenhouse gas. Soil-dwelling high-affinity H2 oxidizing bacteria use this trace gas as an energy source to persist when other substrates are limited or to meet their maintenance energy requirements during dormancy. However, there is limited knowledge of the distribution, composition, diversity, and functions of this group of bacteria, particularly their ecological traits (i.e., characteristics that influence their interactions with the environment and other organisms). This is because the high-affinity H2-oxidizing bacteria are not phylogenetically conserved, potentially due to the horizontal transfer of their functional gene, which still needs to be demonstrated. This makes it difficult to answer ecological questions related to the distribution, functional role, and ecological contribution of H2-oxidizing bacteria in the soil H2 cycle, as well as their responses to environmental factors. Such information is needed to estimate the contribution of the H2-oxidizing bacteria to the global H2 cycle. Although many H2-oxidizing bacteria are not culturable, they may share similar ecological traits when responding to environmental changes, such as pH, moisture content, and H2 concentrations. Therefore, a community or guild-level trait-based approach (defined as the analysis of functional traits shared by groups of bacteria (guilds) that perform similar ecological roles) could be useful to synthesize complex genomic and phylogenetic information. This review discusses the impact of soil environmental factors on soil H2 uptake (by oxidation), and identifies ecological response traits under controlled conditions. Our approach connects the biological activity of the H2-oxidizing bacteria to their resident environment, for scaling up and estimating the capacity of soil microbial communities to mitigate global warming linked to increased atmospheric H2.

Increasing carbon (C) sequestration and stability in agricultural soils is a key strategy to mitigate climate change towards C neutrality. Crop diversification is an initiative to increase C sequestration in fields, but it is unclear how legume-based crop diversification impacts the functional components of soil organic carbon (SOC) in dryland, including the formation and transformation of particulate organic carbon (POC) and mineral-associated organic carbon (MAOC). We investigated the decomposition of straw residues, the fate of photosynthesized C, as well as the formation of MAOC and POC fractions using an in situ13C labeling technique in the soybean-wheat intercropping, soybean-maize intercropping and their respective monocropping systems, with and without cover crops. After 4-year treatments, the total SOC content in bulk soil remained unchanged, while MAOC content increased significantly by 5.6% with intercropping. Moreover, the in situ13C labeling results confirmed that more photosynthesized C was transferred to MAOC, and less was retained in the POC fraction. Intercropping significantly increased total soil N and mineral N content by 15.3% and 13.4%, respectively, and decreased soil and microbial C/N ratio by 11.3% and 17.4%, respectively. This outcome, therefore, relieved microbial N limitation and accelerated straw residue decomposition. Accordingly, the potential of MAOC formation was strengthened for better SOC persistence. Our study suggests that legume-based crop diversification can effectively enrich N and support POC transformation to MAOC, accordingly contributing to the persistent SOC pool and thus potentially achieving C neutrality under climate change in dryland agroecosystems.

Healthy, fertile soil helps reduce nitrogen surpluses, increase carbon sequestration and is the foundation of a nutritious food supply for healthy people on a healthy planet.

Soil high‐affinity H 2 uptake activity can be affected by many factors, including the soil pH. However, the method to determine how pH affects high‐affinity H 2 uptake activity should be updated. The effect of pH on the biological high‐affinity H 2 uptake in agricultural soils was compared using three pH buffer systems in the pH 4–8 range. Soil pH was adjusted to the target pH using a buffer system (1 g soil/5 mL pH buffer). Soil slurries were treated with heat (autoclaving) or a chemical (25% v/w of toluene addition, microbial inhibitor) to inhibit biological activity. Sterile pH buffer was used as a negative control. The sterile soil slurry (heat sterilization) was the optimal reference control for measuring biological high‐affinity H 2 uptake activity. Biological H 2 uptake activity was resistant to toluene, particularly at extreme pH levels. Overall, soil pH ( p = 0.95) and pH buffer systems ( p = 0.46) did not affect the high‐affinity H 2 uptake activity in the tested agricultural soils. We provide an updated method to accurately measure the potential high‐affinity H 2 uptake activity in soil, with an emphasis on the importance of controlling the soil pH.

Soil salinity is a major constraint to soil health and crop productivity, especially in arid and semi-arid regions. The most accurate measurement of soil salinity is considered to be the electrical conductivity of saturated soil extracts (ECe). Because this method is labor-intensive, it is unsuitable for routine analysis in large soil sampling campaigns. This study aimed to identify the best models to estimate soil salinity based on ECe in relation to a rapid electrical conductivity (EC) measurement in soil/water (referred to as S:W henceforward) extracts. We evaluated the relationship between ECe and the ECS:W extract ratios (1:1, 1:2, and 1:5) in salt-affected soils from the semi-arid Sehb El Masjoune region of Morocco. The soil salinity in this region is 0.5 to 235 dS/m, as determined by the ECe method. A total of 125 soil samples, from topsoil (0–15 cm) and subsoil (15–30 cm) with mainly fine to medium textures, were analyzed using linear, logarithmic, and second-order polynomial regression models. The models included all samples or grouped samples according to soil texture (fine, medium) or specific textural classes. The mean ECe values were 2.6, 3.1, and 7.9 times greater than the EC of 1:1, 1:2, and 1:5 S:W extracts, respectively. Polynomial regression models had the best predictive accuracy, R2 = 0.98, and the lowest root mean square error of 10.6 to 10.7 dS/m for the ECS:W extract ratios of 1:5 and 1:2. The polynomial models could represent the non-linear relationships between ECe and salinity indicators, especially in the 80–170 dS/m salinity range, where other models typically underestimate the salinity. These results confirm that advanced regression techniques are suitable for predicting soil salinity in a salt-affected semi-arid region. The site-specific models outperformed previously published models, because they consider the spatial variability and heterogeneity of the salinity in the study area explicitly. This confirms the importance of calibrating soil salinity models according to the local soil and environmental conditions. Consequently, we can undertake soil salinity assessments in hundreds of samples by using the simple, rapid ECS:W extraction method as a direct indicator of EC and extrapolate to ECe with a polynomial regression model. Our approach enables the widespread soil salinity assessments that are needed for land-use planning, irrigation management, and crop selection in salt-affected landscapes.

Agricultural soil is a major sink for microplastics, which accumulate as a consequence of plastic mulching, wastewater irrigation, and the application of organic materials containing plastic residues as soil amendments. Soil organisms like earthworms are sensitive to microplastic exposure. However, a global regulatory gap currently exists regarding small plastic fragments (< 2 mm) in agricultural soils, and there is limited information on the influence of size-dependent microplastics on the direct cellular immune responses of earthworms, particularly under in vitro conditions. In this paper, we conducted an in vitro investigation of the cytotoxicity of polyethylene microplastics in Eisenia fetida coelomocytes, which revealed size-dependent differences in phagocytosis. Coelomocytes engulfed 85

Macroplastics (plastic debris > 2 cm) represent an understudied but increasingly prevalent pollutant in agricultural soils, where they may disrupt nitrogen (N) cycling through physical interference with soil structure, altered microbial communities, and changes in nutrient dynamics. While extensive research has focused on microplastics (< 5 mm), the impacts of macroplastics remain poorly understood in maize cultivation. Hence, this study aimed to investigate how macroplastics (> 2 cm) impact soil-plant N variations, maize performance, and microbial-mediated N transformations in the globally promoted maize-based (maize-soybean) intercropping systems through mesocosm and field experiments. While macroplastics minimally affected aboveground maize morphology and yield, they significantly inhibited root development. Soil NO3--N concentrations reduced, while nitrite reductase activity and 15N retention increased, indicating reduced N uptake by maize and accumulation of unused fertilizer in the macroplastic-treated soils. Notably, denitrifying bacteria and functional genes in the denitrification pathway became more abundant, suggesting heightened potential for N loss. Overall, macroplastics exposure did not alter intercropped maize growth but created soil conditions that could stimulate N loss from the soil-maize system via denitrification. Controlling the denitrification reaction should improve N use efficiency and enhance crop yield in macroplastic-polluted agroecosystems.

The socioeconomic value of content presented at the ASA‐CSSA‐SSSA (where ASA‐CSSA‐SSSA is American Society of Agronomy–Crop Science Society of America–Soil Science Society of America) Annual Meetings from 2014 to 2023 is estimated at $64.2 billion and is presented in this commentary as a thought exercise, highlighting the potential scale of research dissemination in scientific meetings. Scientific meetings are instrumental for propelling the quality and advancement of research via fostering timely feedback, knowledge dissemination, fresh perspectives, stimulation for networking and new collaborations, preparing scientists for public engagement, and addressing contemporary challenges of cultural accessibility and opportunity. Additionally, the broader impacts include near‐term benefits to agricultural and environmental scientists that can transform careers and perspectives on the world, especially for students and early career members. The benefits from these impacts on scientists are then anticipated to propagate into broader and longer term positive impacts on humanity worldwide. In this commentary, we offer the above as a provocation to spark peer discussion on evaluating scientific meetings’ contributions, alongside a working list of broader impacts to inspire philosophical and methodological innovations for quantifying their value.

Understanding how soil biodiversity, especially of macrofauna like earthworms, responds to land-use intensity is crucial for developing sustainable land-use strategies. This work is a two-year field investigation of earthworm community responses to increasing land-use intensity, from undisturbed fallow land to actively cultivated agricultural lands (including fallow land, tea plantation, orange plantation, camphora plantation, synthetic fertilizer-amended cropland, compost-amended cropland, and vermicompost-amended cropland) in a subtropical region. Earthworm abundance and diversity increased with land-use intensity, likely due to the compensatory effects of organic amendments, which improve the habitat and resource availability, thereby alleviating the potential negative impacts of tillage and harvesting. Notably, earthworm abundance was higher in cropland (70 ind. m-2) than in other land-use types, such as fallow (4 ind. m-2) and plantation (22 ind. m-2). Greater earthworm abundance was associated with higher soil pH and more food resources, as indicated by high microbial biomass carbon (C), the humification index, and the particulate organic C fraction. Anecic and endogeic earthworms increased more than epigeic earthworms from fallow lands to plantations and croplands, reflecting their ecological adaptability to the soil conditions in managed lands with higher land-use intensity. This suggests that soil ecological restoration practices may enhance the role of earthworms related to soil structure dynamics and carbon sequestration. Our study provides empirical evidence that soil macrofauna have ecological adaptations to cope with agricultural intensification across landscapes.