Soil Organic Matter

“Across 24 Oregon tall fescue seed fields (stands 2-20 years), total SOC stocks were unchanged by stand age or straw management, but older stands stored more total field-level carbon from greater root inputs and straw retention boosted the labile (particulate) carbon fraction in topsoil along with microbial biomass and respiration. These grass seed fields held less topsoil carbon than nearby natural grasslands but more than arable crop fields, so keeping stands longer and retaining straw supports soil biology even without measurable SOC gains.”

“Across 41 farm sites and five soil series in Central Ohio, woodland soils had consistently lower bulk density and penetration resistance and higher porosity than cropland or meadow, while no-till and minimum till fields showed no clear physical advantage over conventional tillage even after 15+ years. Soil organic carbon explained a moderate share of variation in porosity, bulk density, and compaction (R² ≥ 0.33), suggesting building SOC is the lever — and that structural gains from reduced tillage may take longer than 15 years to show up.”

“Pairing 13C-labeled tracer incubations across sandy-to-loamy soils (17-67% sand) with Cycles model runs for continuous maize in Nebraska and Illinois shows that soil texture strongly controls whether added carbon is respired as CO2 or retained as soil organic matter, and that texture, precipitation and drying-rewetting frequency together with tillage regime (no-till vs. conventional) determine future soil carbon change. The dataset provides the respiration, soil carbon retention and simulated soil organic carbon and maize yield outputs behind those comparisons.”

“Across 50 commercial corn-belt fields in Ohio and Indiana, manure application rate was the strongest and most consistent driver of better soil health across six indicators (organic matter, respiration, POX-C, protein, aggregate stability, bulk density). Reduced tillage helped soil protein and respiration but lowered POX-C, while living cover and crop diversity showed little measurable effect; soil texture explained much of the field-to-field variation, and using 5 years of management history predicted better than 3.”

“Cutting irrigation to 50% of crop ET over six years in Utah barely changed soil organic matter or aggregate stability, though warmer Cedar City saw ACE protein drop from 1.57 to 1.41 g/kg and Vernal soil respiration was 28% higher under full irrigation. Cover cropping was the standout for infiltration, raising field-saturated hydraulic conductivity to 24.62 cm/h versus 5.55 (tilled) and 3.42 (no-till) cm/h.”

“Across 10 long-term Arkansas row-crop trials, soil health indicators (CO2 respiration, β-glucosidase, POXC, organic matter) and composite scores were highest in the top 0-5 cm and declined with depth, and were higher in summer and winter samples than in spring or fall (fall lowest). Cover crops and fertilized treatments scored better than winter fallow and unfertilized plots, so soil health monitoring needs standardized sampling depth and season to make valid comparisons.”

“Twenty-seven years of organic no-till in central Ohio, comparing compost, manure, cover crop and fallow treatments, produced measurable differences in soil physical quality — bulk density, penetration resistance, water-stable aggregates, saturated hydraulic conductivity, organic carbon and plant-available water — at two depths, combined into a single soil physical quality index. The dataset offers a rare long-term benchmark for how organic amendments and continuous cover shape soil structure and water-holding ability.”

“Across 648 soil profiles in North Carolina, particulate organic matter — the fraction most responsive to management — made up 35% of total soil organic C in the top 10 cm but only 10% at 30–60 cm, and was lower in sandier soils. Poultry litter application raised root-zone particulate organic C and N by 17%–32%, and pastures 30 years old held 4%–20% more than newer pastures, while deeper, stable (nonparticulate) carbon was set by long-term soil formation rather than management.”

“After 27 years of no-till in central Ohio, compost and manure raised topsoil (0-20 cm) carbon stocks about 66%-67% above fallow, with compost sequestering 0.85 Mg C/ha/yr and manure adding the most nitrogen (0.061 Mg N/ha/yr); cover crops alone gave a smaller 21%-27% gain. Higher soil carbon tracked better aggregate stability (R2 = 0.76) and lower bulk density, though compost also pushed up salinity near the surface.”

“Cropping systems with perennial vegetation and livestock integration promote soil health.”

“The effect of irrigation and organic amendments on soil CO2 emissions from a Hawai'ian soil.”

“The potential benefits of different types of soil amendments and mulch ground covers on soil chemical and biological properties, crop development and yield, and disease and pest issues in organic vegetable production were evaluated in a two-year field trial in Maine, USA.”

“Soil carbon maintained by perennial grasslands over 30 years but lost in field crop systems in a temperate Mollisol.”

“Long term influence of alternative corn cropping practices on soil health, yields and forage quality.”

“Elucidating relationships between the soil food web, soil processes, and agroecosystem function is a critical step toward a more sustainable agriculture. Soil and crop management practices can alter these relationships, and their effects can persist even after imposing new management practices.”

“Simulated dryland cotton yield response to selected scenario factors associated with soil health.”

“Soil Water Holding Capacity Mitigates Downside Risk and Volatility in US Rainfed Maize.”

“The effects of dryland cropping system intensity on soil function and associated changes in soil macrofauna communities.”

“Organic Soils Control Beetle Survival while Competitors Limit Aphid Population Growth.”

“Organic amendments like compost can enhance soil health and climate change mitigation in managed grasslands. Here, we examined plant and soil biota responses over three growing seasons to better understand how plant–soil feedbacks support net soil organic carbon sequestration under compost.”

“Restoring soil health to reduce irrigation demand and buffer the impacts of drought.”

“The effects of biodynamic preparations were tested in the context of comparisons of conventional, organic, and biodynamic systems and diverse crop rotations.”

“We found that mulch groundcover improves soil fertility and water holding capacity in gardens, and that socio-demographic factors may affect people’s access to mulch to affect soil properties.”

“Whole orchard recycling improves climate change adaptation and mitigation potential of almond production systems.”

“A regional soil classification framework to improve soil health diagnosis and management.”

“Stover harvest increases plant macro and micronutrient removal, but does not affect average grain yields.”

“Effects of golf course management on subsurface soil properties in Iowa.”

“Landscape heterogeneity drives contrasting concentration–discharge relationships in shale headwater catchments.”

“A study using a rapid soil respiration assay to assess soil microbial activity in South Dakota.”

“Cover crop composition in longterm notill soils in semiarid environments do not influence soil health measurements after one year.”

“Use of compost as a soil amendment to increase soil health and to improve crop yields.”

“Reanalysis Validates Soil Health Indicator Sensitivity and Correlation with Longterm Crop Yields.”

“Soil biological and physical measurements did not improve the predictability of corn response to phosphorus fertilization.”

“Assessing how cover crops close the soil health gap in onfarm experiments.”

“Comparing Biological and Conventional Chemical Soil Tests in LongTerm Tillage, Rotation, N Rate Field Study.”

“Multivariate Analysis and Visualization of Soil Quality Data for NoTill Systems.”

“Modeled impacts of cover crops and vegetative barriers on corn stover availability and soil quality.”

“Seasonal Changes of Soil Quality Indicators in Selected Arid Cropping Systems.”

“Bioenergy cropping systems could help offset greenhouse gas emissions, but quantifying that offset is complex.”

“Soil geochemistry as a driver of soil organic matter composition: insights from a soil chronosequence.”

“A common idea of soil carbon processes is that litter decomposition rates and soil carbon stocks are inversely related. To test this overall hypothesis, simultaneous studies were conducted of the relationship of environmental gradients to leaf, wood, buried cloth and percent soil organic matter in Taxodium distichum swamps across the Mississippi River Alluvial Valley and northern Gulf of Mexico of the US.”

“Organic cropping systems enhance soil health indicators in a Mollisol of the US Corn Belt.”

“Positive associations of soil organic matter and crop yields across a regional network of working farms.”

“Cropping system and rotational grazing effects on soil fertility and enzyme activity in an integrated organic crop-livestock system.”

“Prairie restoration on reclaimed mine land was effective in establishing a native plant community, with the associated ecosystem benefits.”

“Effects of Spatial Variability and Drainage on Extracellular Enzyme Activity in Coastal Freshwater Forested Wetlands of Eastern North Carolina, USA.”

“A conceptual framework that advances our understanding of the nexus between plant litter decomposition and SOM formation and leads to improved models of C and N cycling in terrestrial ecosystems is developed and utilized in this study.”

“Crop Residue Management Challenges: A Special Issue.”

“Land Suitability Evaluation for Organic Agriculture of Wheat Using GIS and Multicriteria Analysis.”

“Trends in soil organic matter and topsoil thickness under regenerative practices at the University of Washington student farm.”

“A weighted soil health index approach for refined assessment of soil health in cropping systems.”

“Legume Cover Crop Contributions to Ecological Nutrient Management in Upper Midwest Vegetable Systems.”

“Synergy between compost and cover crops in a Mediterranean row crop system leads to increased subsoil carbon storage.”

“Cereal rye (Secale cereale L.) cover crop improves soil physico-chemical properties with no influence on soybean root growth parameters.”

“Cover crop monocultures and mixtures affect soil health indicators and crop yield in the southeast United States.”

“Soil protein: a key indicator of soil health and nitrogen management.”

“SHAPEv1.0 Scoring curves and peer group benchmarks for dynamic soil health indicators.”

“Interaction of soil health indicators to different regenerative farming practices on mineral soils.”

“Linking soil health indicators to management history and soybean yield.”

“Hemp biochar impacts on selected biological soil health indicators across different soil types and moisture cycles.”

“Regenerative almond production systems improve soil health, biodiversity, yield, and profit.”

“Midinfrared spectroscopy for prediction of soil health indicators in the United States.”

“Farmers’ insights on soil health indicators and adoption.”

“Cover crop functional types differentially alter the content and composition of soil organic carbon in particulate and mineralassociated fractions.”

“Cover crops and reduced tillage did not alter soil chemistry in first 3 years.”

“Reduced tillage and rotational diversity improve soil health in Missouri.”

“Cover cropping and conservation tillage improve soil health in the southeastern United States.”

“The long-term effect of crop rotation and tillage on soil microbial community composition.”

“Iron-mediated organic matter decomposition in humid soils can counteract protection.”

“Lowintensity frequent fires in coniferous forests transform soil organic matter in ways that may offset ecosystem carbon losses.”

“White clover living mulch enhances soil health vs. annual cover crops.”

“This study evaluated the effect of variable natural lighting on the accuracy of soil color determination using the Munsell color charts.”