Soil Test

“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.”

“A yield-correlated minimum soil dataset — total organic carbon, microbial biomass carbon, active carbon, total nitrogen and aggregate stability — tracked full-dataset soil quality scores closely (R² 0.53–0.93) and beat the usual PCA-selected indicator set. Pairing linear scoring that uses threshold limits with simple additive indexing kept soil quality index values within ±1% of the full dataset, giving farmers and advisers a cheaper, transferable way to rate soil quality across corn–soybean sites in Alabama, Indiana and Ohio.”

“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.”