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Grazed pastures supporting ruminant livestock have not been well characterized for soil health condition. However, growing interest in holistic management of compromised watersheds suggests that grazing lands deserve more attention for their capacity to provide ecosystem services. Relatively little is known about how grazing management affects soil aggregation and other surface‐soil properties on private lands in the eastern United States. This study investigated the effects of land use (conventional‐till cropland, no‐till cropland, grassland, and woodland) and pasture management characteristics on soil aggregation, bulk density, sieved soil density, total soil N, and soil‐test biological activity on 31 private farms distributed across the western half of Virginia. Soil stability index followed the order (p < 0.05): conventional‐till cropland (0.60 mm mm−1) < no‐till cropland (0.78 mm mm−1) < woodland (0.85 mm mm−1) = grassland (0.89 mm mm−1). Surface soil characteristics improved with pasture age due to organic matter recycling from residual forage mass and animal excreta. Increases in total soil N and soil‐test biological activity helped create water‐stable aggregation and reduce soil bulk density. Soil stability index was optimized with moderate stocking rate of 0.5–1.1 Mg live weight ha−1. Stocking method did not affect soil aggregation or bulk density. Soil stability index declined with increasing N fertilization rate. Soil aggregation characteristics were generally not affected by organic amendment, quantity of hay fed on farm, or occasional hay harvest from pastures, likely because aggregation was high across management variables. Well‐managed grazed pastures in Virginia are creating desirable conservation agricultural land uses to protect watershed quality. Core Ideas: Soil aggregation under grazed pastures was stable and at a higher level than under cropland.Soil bulk density at 0‐ to 10‐cm depth declined with increasing level of conservation land use.Water‐stable mean‐weight diameter of soil aggregates had stronger association with soil‐test biological activity than with sand fraction.High soil stability index under mature grazed pastures may help mitigate against soil erosion and nutrient loss.Evidence was not supportive of rotational stocking as a practice to improve surface‐soil characteristics. [ABSTRACT FROM AUTHOR]

Biologically active and intermediately labile fractions of soil organic matter are important features of conservation agricultural management systems. Depth distribution of soil‐test biological activity (STBA) and particulate organic carbon (C) and nitrogen (N) were characterized under cropland, grassland, and woodland across 25 research stations in North Carolina. Most (87%) of the 310 fields sampled were on Ultisols (udults or aquults). Variation in STBA in the surface 30‐cm of soil was controlled primarily by land use and to a lesser extent by soil texture and physiographic region. Baseline concentrations of STBA and particulate organic C and N at 30‐cm depth were relatively narrowly constrained compared with contents in the 0‐ to 10‐cm depth. Root‐zone enrichment (i.e., total minus baseline contents) of STBA (mean ± standard error; kg CO2–C ha−1 3 d−1) followed the order: conventional‐till cropland (194 ± 17) < no‐till cropland (274 ± 26) < woodland (421 ± 17) < grassland (537 ± 15) across locations. Proportion of root‐zone enrichment of soil organic C as particulate organic C was 43 ± 2%. Root‐zone enrichment of particulate organic C (Mg C ha−1) followed the order: conventional‐till cropland (3.8 ± 0.6) < no‐till cropland (8.7 ± 0.8) < grassland (14.1 ± 0.5) < woodland (16.3 ± 0.6) across locations. The C:N ratio of root‐zone‐enriched particulate organic matter was greater under woodland than under other land uses likely because of N input limitations. Conservation land uses increased root‐zone enrichment of these active and intermediately labile fractions independent of soil types and regions in the state. Core Ideas: Root‐zone enrichment calculations were sensitive to conservation land uses.As a proportion of total root‐zone enrichment of soil‐test biological activity (STBA), 68 ± 7% occurred in the 0‐ to 10‐cm depth.Grasslands and woodlands had greater root‐zone enrichment of particulate organic C and N than croplands.No‐till cropland had greater root‐zone enrichment of STBA and particulate organic C and N than conventional‐till cropland.Greater C:N ratio of root‐zone‐enriched particulate organic matter under woodlands may have been from lack of N input. [ABSTRACT FROM AUTHOR]

Conservation agricultural systems have a long history of development and use in the southeastern United States, but they are still not the norm on the landscape. Literature from the region suggests that a diversity of soil properties can be improved with cover cropping and conservation tillage, but results are not always consistent. Our objectives were to (a) review recent research on conservation tillage and cover cropping in the region and (b) compile and synthesize recent data from a diversity of farms along a conventional to conservation gradient. As part of recent on‐farm trials focused on soil N availability, we analyzed soil organic C and N fractions and routine soil nutrient characteristics from a total of 196 fields in corn (Zea mays L.), wheat (Triticum aestivum L.), and barley (Hordeum vulgare L.) production in three physiographic regions of the Coastal Plain (n = 71 fields), Piedmont (n = 77 fields), and Appalachians (n = 48 fields) in North Carolina, South Carolina, Pennsylvania, and Virginia. These data allowed us to establish first estimates of threshold optima for soil organic C and N fractions and other inorganic nutrients. On‐farm data confirmed the literature review that conservation tillage resulted in greater stratification of soil organic C and N and nutrient concentrations. Soil health improvement could be inferred along the gradient from inversion tillage to no tillage without cover cropping to no tillage with cover cropping. This collection of recent literature and on‐farm data can be a useful starting point for establishing target limits and assessing soil health conditions on farms in the region. Core Ideas: There was significant improvement in soil organic C and N and inorganic nutrients with no‐till and covers.Soil health improved with adoption of no‐till compared with inversion tillage.There was weak evidence for soil health improvement with multi‐species covers compared to single species.Soil‐test biological activity and net N mineralization are effective indicators of soil health. [ABSTRACT FROM AUTHOR]