Proceedings - Soil Science Society of America最新文献

Barley (Hordeum vulgare L.) is the primary grain used for malting and brewing in the United States. Idaho accounts for upward of 40% of US production with the largest share grown under irrigation in the Snake River Plain. Cultivar and agronomic advancements occurred in the past century but, N-supply research has lagged behind. We addressed this with N-response trials of historical and modern malt barley cultivars from 2015 to 2019. Six N-supplies (applied fertilizer-N + soil inorganic-N) were tested, allowing critical nitrogen supply (CNS) determination, that is, N-supply at yield plateau. Site-by-site analysis of variance (ANOVA) and linear plateau (LP) models were used to determine ANOVA CNS, which ranged from 110 to 149 kg N ha⁻¹. At ANOVA CNS, modern barley yields were 10%–20% greater than historical cultivars. Combined-site LP and quadratic plateau (QP) models resulted in CNS ranges of 117–152 kg N ha⁻¹ for historical cultivars and 141–170 kg N ha⁻¹ for modern cultivars; both model results are below the current maximum recommendation of 235 kg N ha⁻¹. Grain yields for Klages were 20%–35% greater than reported from research in the 1970s and 1980s; however, CNS were similar. Grain protein was more negatively affected by N-supply for Klages, but all cultivars remained below malting thresholds across their CNS ranges. Our data support lower fertilizer-N applications and expenditures compared to current recommendations and evidence the importance of synergistic enhancement of malt barley production through breeding and agronomic advancement to optimize crop and farm business performance.

Soil aggregate stability is critical for maintaining soil fertility and mitigating environmental issues like erosion, yet the mechanisms by which interparticle interactions (van der Waals attraction, and electrostatic and hydration repulsion) govern stability across aggregate sizes remain unclear. This study investigated the distribution characteristics, influencing factors, and mechanisms of interparticle forces affecting aggregate structure stability for different-sized aggregates (2–5, 1–2, 0.25–1, 0.053–0.25 mm) using the pipette method and soil electrochemical theory. Results revealed that aggregate stability decreases significantly as electrolyte concentration decreases, with larger aggregates exhibiting stronger stability due to net attractive forces dominating interparticle interactions. In contrast, smaller aggregates experienced repulsion-dominated forces, reducing stability. The differential distribution of clay particles within aggregates of varied sizes altered surface charge density, surface potential, and electric field strength. Specifically, the high clay content in larger aggregates increased specific surface area, reducing surface charge density and weakening electrostatic repulsion, thereby enhancing stability. Electrochemical trends aligned with stability patterns, providing a robust explanation for size-dependent behavior. These findings clarify how clay distribution and interparticle forces govern aggregate stability, advancing mechanistic insights into soil structure dynamics. By quantifying the role of internal forces at the mesoscale, this study offers a foundation for targeted management practices to enhance soil resilience against environmental stressors like erosion and nonpoint source pollution.

Filippi, D., Gatiboni, L., Crozier, C., Osmond, D., & Hardy, D. (2025). Effect of model choice on critical soil test value of phosphorus for corn in long-term trials in North Carolina. Soil Science Society of America Journal, 89, e70104. https://doi.org/10.1002/saj2.70104

On the “Plain Language Summary” section, the text “critical p-value” and “critical p-values” were incorrect. This should have read: “critical P value” and “critical P values.”

We apologize for this error.

Land degradation occurs primarily through soil erosion and hydrological instability. The role of vegetation growth stages, specifically germination, greening, flowering, live root, and dead root, in runoff and soil erosion control lacks sufficient investigation. The current research, therefore, examines runoff and soil loss during five successive growth stages of Trifolium pratense, which functions as an essential forage species for rangeland rehabilitation under simulated rainfall conditions. The study executed controlled laboratory experiments using soil collected from the Kojour Watershed, northern Iran. The experiment utilized rainfall simulations (50 mm h⁻¹ intensity, 20% slope, 30-min duration) on vegetated and bare (control) plots to mimic regional rainfall conditions while maintaining statistical control for robust comparative assessments. The experimental data show that vegetated plots yielded more favorable results by generating 1.27–1.65 times less runoff volume and lowering soil loss by factors of 1.15–4.99 times. The flowering stage demonstrated maximum erosion control because its roots and canopy reached their peak developmental stage. The results also showed that the above-ground plant biomass primarily controlled splash erosion, but the roots basically strengthened the soil via binding and bonding effects to achieve stabilization. The research showed that vegetation primarily assists by stopping soil detachment rather than significantly affecting runoff. The study exclusively focused on T. pratense, so additional research should investigate whether these findings apply to other plant species. Research success will improve runoff and soil erosion-controlling strategies and be a starting point for further studies on rangeland species functions.

In this study, an electron shuttle, anthraquinone-2,6-disulfonate (AQDS), was employed to construct quinone group modified sludge-based biochar (AQDS-SBC). The graft of quinone functional groups brought a higher level of aromatic structure and the effect of AQDS-SBC on the biodegradation of naphthalene was explored. The removal of naphthalene was improved by 80.67% with the addition of AQDS-SBC, and the degradation of naphthalene follows the pseudo-first-order kinetic. Furthermore, the results of electrochemical measurements suggested that the presence of quinone-like groups in AQDS-SBC as redox-active centers might play an important role in mediating extracellular electron transfer (EET), thereby accelerating the degradation of naphthalene. The microbial community analysis indicated that naphthalene-degrading bacteria (Phanerochaete chrysosporium and Pleurotus ostreatus) and EET-functional bacteria (Geobacter) were enriched in the presence of AQDS-SBC, which promoted the synergistic effect of multiple microorganisms and provided multiple modes of electron transfer to degrade naphthalene. In conclusion, this experiment verified that EET mediated by AQDS-SBC enhanced the degradation of naphthalene and provided a reference for the bioremediation of petrochemical-contaminated soil.

Characterizing field-saturated hydraulic conductivity (K_fs) in soil is important because K_fs data are needed for a variety of applications. However, different K_fs measurement methods often yield vastly different results. This study aimed to evaluate the ability of five methods to detect variations in measured K_fs across land use in glacial till soils. We compared the lab intact core method with four in-field methods, including the compact constant head well permeameter (Amoozemeter) and three single-ring infiltrometers: Cornell sprinkle infiltrometer, dual-head infiltrometer (SATURO), and a consistent head single-ring infiltrometer. Ten plots were established along a transect in six field sites with varying land uses (forest, corn [Zea mays L.], hay, vegetable, and turf). One measurement was taken per plot for each method. Overall, K_fs estimates from the Amoozemeter were consistently lower than those from field infiltrometers. All methods revealed higher surface K_fs in the forest than the intensively cultivated sites; however, the Amoozemeter and the ring-based methods revealed different K_fs patterns among managed sites. Despite differences in water application procedures, the field infiltrometers produced similar K_fs estimates, suggesting their interchangeability in applications for assessing land use and management impacts on surface K_fs in glacial till soils.

This study evaluates the feasibility of storing phosphogypsum (PG) on lime-stabilized red soils (RS) and quantifies the synergistic stabilization capacity of PG-hydraulic lime (L) blends. Mortar specimens with variable RS/L/PG ratios underwent comprehensive physicochemical (pH, electrical conductivity [EC], X-ray fluorescence [XRF]), geotechnical (Atterberg limits), mineralogical (X-ray diffraction [XRD], Fourier transform infrared [FTIR]), microstructural (scanning electron microscopy [SEM]/energy dispersive spectroscopy [EDS]), thermogravimetric (differential thermal analysis coupled with thermogravimetric analysis [DTA-TG]), and mechanical (unconfined compressive strength [UCS]) characterization. Box–Behnken design (BBD) was applied to delineate the influence of varying proportions of RS, L, and PG on the mechanical performance of stabilized soil composites. The results establish that 10 wt% L with ≤32 wt% PG significantly enhances soil performance. The UCS increased from 1.67 MPa (RS + 2%L) to 4.48 MPa (RS + 10%L + 32%PG), and the plasticity index decreased from 17.47% (untreated RS) to 12.64% (RS + 10%L + 10%PG). Critically, PG addition did not induce ettringite formation despite available sulfate ions (SO₄²⁻), aluminol/silicate groups, Ca²⁺, and OH⁻ ions, eliminating the risks of sulfate-induced expansion. Scanning electron microscopy (SEM) revealed rod-shaped gypsum microcrystals (CaSO₄·2H₂O) on particle surfaces, accelerating hydration kinetics and strengthening mechanical performance through microstructural densification. This study establishes PG as a sustainable co-additive that concurrently mitigates industrial waste liabilities and enhances geotechnical performance in marginal red soils. Component synergies rigorously quantified via BBD provide a mechanistic blueprint for eco-engineered infrastructure and circular waste management strategies.

Coastal environments face a growing number of challenges as a result of a changing climate (e.g., sea level rise, flooding, and erosion). In response, intertidal and subaqueous soils (SAS) are being mapped to provide a soil resource inventory for use and management decisions. An essential part of any soil resource inventory is particle size distribution (PSD) analysis. Coastal soils have elevated levels of salts and sulfides that can complicate PSD analysis, requiring time-intensive pretreatments. We tested a regression model to reduce reliance on labor-intensive methods for PSD analysis. Analysis of 257 SAS samples revealed a strong sand–silt relationship (p < 0.0001; r² = 0.975), allowing for accurate silt and clay prediction from sand content. For samples with >40% sand (70% of the 257 samples), average absolute residuals of predicted silt ranged from 0.80% to 3.58%. Randomized iterative testing (10,000 iterations) showed that as few as 50 samples of the original 257 could be used to develop a model to provide PSD data with <4% absolute error for predicting silt for samples with >40% sand. Accuracy of the model declined for samples with ≤40% sand, especially <20% sand where average absolute residuals ranged from 7% to 8%. We hypothesized that diatom skeletons disrupted the sand–silt relationship in the silt-dominated samples, which contained as many as 9% diatoms. The regression model developed in this study offers a faster, more time- and cost-effective alternative for determining PSD analysis in SAS with >40% sand, aiding large-scale soil survey efforts.

The availability of low-cost and renewable electricity in Finland has encouraged practitioners to explore electroosmosis for consolidating soft clay. However, the shrinkage and soil water retention characteristics of soft sensitive clays after application of electroosmosis remain underexplored. Current study presents the laboratory electroosmotic dewatering experiments conducted on meticulously sampled undisturbed Finnish clays. The hydraulic properties, consolidation potential, shrinkage curves, and soil water retention characteristics, along with the electro-chemical changes, were evaluated at 10, 20, and 30 V. Electroosmotic treatment resulted in a two-order magnitude (10²) increase in dewatering rate and up to 22% settlement, outperforming conventional incremental loading methods. Significant pH variations induced near electrodes altered clay microstructure: dispersed nature increased the minimum void ratio (e_min) near the 10 V cathode (up to 35%), while flocculated nature near the 30 V anode reduced it by 5% as compared to undisturbed sample. The effect of pH on the shrinkage limit (SL) was evident, as acidification reduced the SL, while it increased under alkaline conditions at each voltage. The air-entry value decreased near cathodes and increased near anodes at each voltage, reflecting voltage-dependent alterations in soil water retention curves at both ends. Additionally, the degradation of Si–O functional groups near the anode (up to 27%) and their enrichment near the cathode (up to 70%) indicate mineralogical reorganization induced by electroosmotic treatment. The preliminary findings from this study encourage exploring electroosmosis to self-consolidate soft sensitive clay in field conditions.

Tobacco–rice rotation cropping (TRRC) can optimize the physical and chemical properties of the soil, improve soil fertility, and increase yields of tobacco (Nicotiana tabacum) and rice (Oryza sativa). However, there is a lack of attention to the quality of rice affected by TRRC. This study aims to investigate the effects of TRRC on rice quality and soil nutrient availability. Comparative analysis was conducted between TRRC and single-season rice (R mode) areas over 2 years, assessing rice quality metrics and soil nutrient profiles. The results indicated that rice quality significantly improved in TRRC areas, evidenced by an increase of 0.3%–1650% in metrics such as protein content and amylose content, with a notable reduction in cadmium (Cd) levels. Comparing with R mode, the content of organic matter and the available nitrogen (N) was respectively reduced 1.3%–73.3% and 3.8%–84.6% in soils of TRRC mode, while the content of available potassium (K) and available phosphorus (P) was respectively increased 4.0%–84% and 6.8%–95%. Pesticide residue detection of rice in TRRC area and R mode area meets the national pesticide residue standards for rice in China. These findings suggest that TRRC can optimize rice production and safety in Cd-contaminated regions.