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- Author:
- M. D. Tomer, et al. ; D. E. James; L. A. Schipper; S. A. Wills; Show all 4 Authors
- Source:
- Soil Science Society of America journal 2017 v.81 no.6 pp. 1463-1474
- ISSN:
- 0361-5995
- Subject:
- A horizons; Alfisols; Mollisols; Natural Resources Conservation Service; agricultural soils; basins; cropland; databases; farming systems; soil organic carbon; soil profiles; soil surveys; total nitrogen; Corn Belt region
- Abstract:
- ... Recently, the USDA–NRCS National Cooperative Soil Survey Soil Characterization Database (NSCD) was reported to provide evidence that total nitrogen (TN) stocks of agricultural soils have increased across the Mississippi basin since 1985. Unfortunately, historical changes in methods used to measure TN were not fully accounted for in that report. We used NSCD archives to calibrate between wet (pre-1 ...
- Handle:
- 10113/6592651
- DOI:
- 10.2136/sssaj2017.06.0198
- https://doi.org/10.2136/sssaj2017.06.0198
- Author:
- M. D. Tomer, et al. ; G. H. Merten; H. L. Welch; Show all 3 Authors
- Source:
- Journal of soil and water conservation 2016 v.71 no.3 pp. 267-278
- ISSN:
- 0022-4561
- Subject:
- agricultural watersheds; alluvial plains; anthropogenic activities; basins; conservation tillage; conventional tillage; overland flow; rain; rivers; sediment yield; sediments; soil; suspended sediment; tile drainage; topographic slope; Iowa; Mississippi
- Abstract:
- ... The specific sediment yield (SSY) from watersheds is the result of the balance between natural, scale-dependent erosion and deposition processes, but can be greatly altered by human activities. In general, the SSY decreases along the course of a river as sediments are trapped in alluvial plains and other sinks. However, this relation between SSY and basin area can actually be an increasing one whe ...
- Handle:
- 10113/6757206
- DOI:
- 10.2489/jswc.71.3.267
- https://doi.org/10.2489/jswc.71.3.267
- Author:
- M. D. Tomer, et al. ; J. L. Hatfield; R. M. Cruse; Show all 3 Authors
- Source:
- Marine & freshwater research 2013 v.64 no.5 pp. 423-435
- ISSN:
- 1323-1650
- Subject:
- crop production; soil conservation; anaerobic conditions; world markets; agricultural land; ecosystem services; soil degradation; soil; agricultural industry; climate change; food availability; hydrology; food production; grains; soil management; soil resources; climate; Midwestern United States; Gulf of Mexico
- Abstract:
- ... Society faces substantial challenges to expand food production while adapting to climatic changes and ensuring ecosystem services are maintained. A convergence of these issues is occurring in the Midwestern United States, i.e. the ‘cornbelt’ region that provides substantial grain supplies to world markets but is also well known for its contribution to hypoxic conditions in the Gulf of Mexico due t ...
- DOI:
- 10.1071/MF12164
- https://doi.org/10.1071/MF12164
- Author:
- M. D. Tomer, et al. ; X. Zhou; M. J. Helmers; H Asbjornsen; R. Kolka; Show all 5 Authors
- Source:
- Journal of soil and water conservation 2014 v.69 no.1 pp. 54-64
- ISSN:
- 0022-4561
- Subject:
- Glycine max; Zea mays; agricultural land; agricultural watersheds; corn; cropping systems; filter strips; landscapes; losses from soil; nitrogen; nitrogen content; nutrients; phosphorus; pollution load; prairies; runoff; soil nutrient dynamics; Iowa
- Abstract:
- ... Nitrogen (N) and phosphorus (P) from agricultural landscapes have been identified as primary sources of excess nutrients in aquatic systems. The main objective of this study was to evaluate the effectiveness of prairie filter strips (PFS) in removing nutrients from cropland runoff in 12 small watersheds in central Iowa. Four treatments with PFS of different spatial coverage and distribution (No-PF ...
- Handle:
- 10113/58238
- DOI:
- 10.2489/jswc.69.1.54
- https://doi.org/10.2489/jswc.69.1.54
- Author:
- M. D. Tomer, et al. ; K. M. B. Boomer; S. A. Porter; B. K. Gelder; D. E. James; E. McLellan; Show all 6 Authors
- Source:
- Journal of environmental quality 2015 v.44 no.3 pp. 768-779
- ISSN:
- 0047-2425
- Subject:
- buffers; classification; digital elevation models; ecosystem services; groundwater; landforms; lidar; planning; pollution load; riparian areas; riparian buffers; runoff; sediments; streambank stability; streams; vegetation; water table; watersheds; Illinois; Iowa
- Abstract:
- ... A watershed’s riparian corridor presents opportunities to stabilize streambanks, intercept runoff, and influence shallow groundwater with riparian buffers. This paper presents a system to classify these riparian opportunities and apply them toward riparian management planning in hydrologic unit code 12 watersheds. In two headwater watersheds from each of three landform regions found in Iowa and Il ...
- Handle:
- 10113/60766
- DOI:
- 10.2134/jeq2014.09.0387
- https://doi.org/10.2134/jeq2014.09.0387
- Author:
- M. D. Tomer, et al. ; P. C. Beeson; C. S. T. Daughtry; E. R. Jr. Hunt; B. Akhmedov; A. M. Sadeghi; D. L. Karlen; Show all 7 Authors
- Source:
- Journal of soil and water conservation 2016 v.71 no.5 pp. 385-395
- ISSN:
- 0022-4561
- Subject:
- Glycine max; Landsat; Zea mays; conservation practices; conservation tillage; corn; crop residues; glacial till; labor; protocols; remote sensing; roadsides; soil; soybeans; surveys; thematic maps; watersheds; Iowa
- Abstract:
- ... Quantifying crop residue cover is crucial for identifying tillage intensity and evaluating effectiveness of conservation management practices across large geographic areas. Current assessment protocols are labor intensive, time consuming, and costly. Our objective was to assess crop residue cover and soil tillage intensity in a watershed in central Iowa for three years (2009 to 2011) using multisp ...
- Handle:
- 10113/6472234
- DOI:
- 10.2489/jswc.71.5.385
- https://doi.org/10.2489/jswc.71.5.385
- Author:
- M. D. Tomer, et al. ; Michael W. Van Liew; Charles S. Wortmann; Daniel N. Moriasi; Kevin W. King; Dennis C. Flanagan; Tammie L. Veith; Gregory W. McCarty; David D. Bosch; Show all 9 Authors
- Source:
- Transactions of the ASABE 2017 v.60 no.1 pp. 123-146
- ISSN:
- 2151-0032
- Subject:
- Agricultural Research Service; agricultural policy; agricultural watersheds; crop yield; cropping systems; data collection; land management; models; nitrogen; nutrients; pastures; phosphorus; sediments; soil; statistics; stream flow; topography; water quality; United States
- Abstract:
- ... To better understand the Agricultural Policy Environmental Extender (APEX) model’s strengths and limitations in simulating streamflow and water quality, we evaluated its performance under a diverse range of climatic, topographic, soil, cover, and land management conditions using three parameter settings: best professional judgment (BPJ), partially calibrated, and fully calibrated. A total of 18 ca ...
- Handle:
- 10113/6558888
- DOI:
- 10.13031/trans.11903
- https://doi.org/10.13031/trans.11903
- Author:
- M. D. Tomer, et al. ; J. D. Garbrecht; M. A. Nearing; F. Douglas Shields; E. J. Sadler; J. V. Bonta; C. Baffaut; Show all 7 Authors
- Source:
- Journal of soil and water conservation 2014 v.69 no.5 pp. 374-392
- ISSN:
- 0022-4561
- Subject:
- Conservation Effects Assessment Project; agricultural management; agricultural watersheds; bank erosion; climate; climate change; conservation practices; energy; funding; planning; plant cultural practices; rain; rangelands; rivers; runoff; sediment transport; sediment yield; sediments; soil; soil conservation; streams; watershed hydrology; Arizona; Iowa; Mississippi; Missouri; Oklahoma
- Abstract:
- ... Selected watershed studies of the Conservation Effects Assessment Project (CEAP) are reviewed and findings are interpreted from the perspective of potential conservation outcomes due to climate change scenarios. Primary foci are runoff, soil erosion, sediment transport, and watershed sediment yield. Highlights, successes, and challenges with regards to climate change impacts on soil erosion, runof ...
- Handle:
- 10113/60551
- DOI:
- 10.2489/jswc.69.5.374
- https://doi.org/10.2489/jswc.69.5.374
- Author:
- M. D. Tomer, et al. ; S. A. Porter; K. M. B. Boomer; D. E. James; J. A. Kostel; M. J. Helmers; T. M. Isenhart; E. McLellan; Show all 8 Authors
- Source:
- Journal of environmental quality 2015 v.44 no.3 pp. 754-767
- ISSN:
- 0047-2425
- Subject:
- buffers; computer software; conservation practices; cover crops; cropland; databases; drainage water; environmental quality; geographic information systems; hypoxia; land use; landscapes; nitrate nitrogen; planning; pollution load; prioritization; simulation models; soil properties; spatial data; streams; subsurface drainage; topography; vegetated waterways; watersheds; wetlands; Gulf of Mexico; Illinois; Iowa
- Abstract:
- ... Spatial data on soils, land use, and topography, combined with knowledge of conservation effectiveness, can be used to identify alternatives to reduce nutrient discharge from small (hydrologic unit code [HUC]12) watersheds. Databases comprising soil attributes, agricultural land use, and light detection and ranging–derived elevation models were developed for two glaciated midwestern HUC12 watershe ...
- Handle:
- 10113/60765
- DOI:
- 10.2134/jeq2014.09.0386
- https://doi.org/10.2134/jeq2014.09.0386
- Author:
- M. D. Tomer, et al. ; C. G. Wilson; T. B. Moorman; K. J. Cole; D. Heer; T.M. Isenhart; Show all 6 Authors
- Source:
- Journal of environmental quality 2010 v.39 no.3 pp. 882-895
- ISSN:
- 1537-2537
- Subject:
- sediment yield; water pollution; Escherichia coli; water quality; stormwater; sheet erosion; agricultural runoff; nitrate nitrogen; streams; nonpoint source pollution; rain; watershed hydrology; tile drainage; pollution load; phosphorus; rill erosion; agricultural watersheds; Iowa
- Abstract:
- ... A watershed's water quality is influenced by contaminant-transport pathways unique to each landscape. Accurate information on contaminant-pathways could provide a basis for mitigation through well-targeted approaches. This study determined dynamics of nitrate-N, total P, Escherichia coli, and sediment during a runoff event in Tipton Creek, Iowa. The watershed, under crop and livestock production, ...
- Handle:
- 10113/43845
- DOI:
- 10.2134/jeq2009.0289
- PubMed:
- 20400584
- https://doi.org/10.2134/jeq2009.0289
- Author:
- M. D. Tomer, et al. ; D. E. James; Show all 2 Author
- Source:
- Soil Science Society of America journal 2004 v.68 no.6 pp. 1905-1915
- ISSN:
- 0361-5995
- Subject:
- topography; soil surveys; watersheds; conservation practices; soil erosion; Iowa
- Abstract:
- ... Terrain analyses may help target conservation practices, but soil survey is the traditional basis for conservation planning. This study's objective was to identify correspondence between terrain and soil survey attributes. Iowa's South Fork (78000 ha) and West Nishnabotna (64000 ha) watersheds provided example datasets. Major resource concerns are soil wetness in the South Fork's glacial terrain, ...
- Handle:
- 10113/2490
- DOI:
- 10.2136/sssaj2004.1905
- https://doi.org/10.2136/sssaj2004.1905
- Author:
- M. D. Tomer, et al. ; D. W. Meek; L. A. Kramer; Show all 3 Authors
- Source:
- Journal of environmental quality 2005 v.34 no.5 pp. 1547-1558
- ISSN:
- 1537-2537
- Subject:
- Zea mays; agricultural watersheds; base flow; conservation practices; conventional tillage; corn; drought; hills; infiltration (hydrology); loess; models; ridge tillage; runoff; statistical analysis; streams; terraces; terracing; variance; watershed hydrology; Iowa
- Abstract:
- ... Agricultural tillage influences runoff and infiltration, but consequent effects on watershed hydrology are poorly documented. This study evaluated 25 yr (1971–1995) hydrologic records from four first-order watersheds in Iowa's loess hills. Two watersheds were under conventional tillage and two were under conservation (ridge) tillage, one of which was terraced. All four watersheds grew corn (Zea ma ...
- DOI:
- 10.2134/jeq2004.0199
- https://doi.org/10.2134/jeq2004.0199
- Author:
- M. D. Tomer, et al. ; M. R. Burkart; Show all 2 Author
- Source:
- Journal of environmental quality 2003 v.32 no.6 pp. 2158-2171
- ISSN:
- 1537-2537
- Subject:
- agricultural watersheds; nitrogen fertilizers; fertilizer application; application rate; long term experiments; groundwater contamination; nitrate nitrogen; leaching; base flow; groundwater flow; Iowa
- Abstract:
- ... Changes in agricultural management can minimize NO₃–N leaching, but then the time needed to improve ground water quality is uncertain. A study was conducted in two first-order watersheds (30 and 34 ha) in Iowa's Loess Hills. Both were managed in continuous corn (Zea mays L.) from 1964 through 1995 with similar N fertilizer applications (average 178 kg ha⁻¹ yr⁻¹), except one received applications a ...
- Handle:
- 10113/47973
- DOI:
- 10.2134/jeq2003.2158
- PubMed:
- 14674538
- https://doi.org/10.2134/jeq2003.2158
- Author:
- M. D. Tomer, et al. ; E. J. Sadler; R. E. Lizotte; R. B. Bryant; T. L. Potter; M. T. Moore; T. L. Veith; C. Baffaut; M. A. Locke; M. R. Walbridge; Show all 10 Authors
- Source:
- Journal of soil and water conservation 2014 v.69 no.5 pp. 365-373
- ISSN:
- 0022-4561
- Subject:
- Agricultural Research Service; Conservation Effects Assessment Project; agricultural watersheds; agrochemicals; climate; conservation practices; cover crops; cropland; ecosystem services; ecosystems; farm management; hydrologic models; land use; nutrient retention; nutrients; phosphorus; pollution load; risk; runoff; sediment yield; sediments; soil quality; stream channels; water conservation; water quality; watershed hydrology; watershed management; winter
- Abstract:
- ... Ten years ago, the USDA Agricultural Research Service (ARS) began a series of watershed assessment studies as part of the Conservation Effects Assessment Project (CEAP). In this overview, a decade of research progress in 14 watersheds dominated by rain-fed croplands is reviewed to introduce a special section of this journal issue containing papers describing multiwatershed syntheses. The papers ev ...
- Handle:
- 10113/60550
- DOI:
- 10.2489/jswc.69.5.365
- https://doi.org/10.2489/jswc.69.5.365
15. Surface-Soil Properties and Water Contents across Two Watersheds with Contrasting Tillage Histories
- Author:
- M. D. Tomer, et al. ; C. A. Cambardella; D. E. James; T. B. Moorman; Show all 4 Authors
- Source:
- Soil Science Society of America journal 2006 v.70 no.2 pp. 620-630
- ISSN:
- 0361-5995
- Subject:
- ridge tillage; Zea mays; soil organic carbon; no-tillage; soil water content; conventional tillage; corn; bulk density; water holding capacity; spatial variation; soil texture; altitude; soil water potential; soil density; agricultural watersheds; Iowa
- Abstract:
- ... Soil properties and water contents (θ) vary spatially, but management effects on spatial patterns are poorly understood. This study's objective was to compare surface-soil properties and θ in two small watersheds (30–43 ha) in Iowa's loess hills. Both watersheds were in continuous corn (Zea mays L.) from 1972 through 1995, one (CW1) under conventional tillage and the other (RW3) under ridge tillag ...
- Handle:
- 10113/4149
- DOI:
- 10.2136/sssaj2004.0355
- https://doi.org/10.2136/sssaj2004.0355
- Author:
- M. D. Tomer, et al. ; D. W. Meek; D. B. Jaynes; J. L. Hatfield; Show all 4 Authors
- Source:
- Journal of environmental quality 2003 v.32 no.2 pp. 642-653
- ISSN:
- 1537-2537
- Subject:
- autocorrelation; best management practices; constructed wetlands; denitrification; nitrate nitrogen; temperature; water quality; watersheds; Iowa; Mississippi River
- Abstract:
- ... Nitrate N fluxes from tile-drained watersheds have been implicated in water quality studies of the Mississippi River basin, but actual NO₃–N loads from small watersheds during long periods are poorly documented. We evaluated discharge and NO₃–N fluxes passing the outlet of an Iowa watershed (5134 ha) and two of its tile-drained subbasins (493 and 863 ha) from mid-1992 through 2000. The cumulative ...
- DOI:
- 10.2134/jeq2003.6420
- PubMed:
- 12708689
- https://doi.org/10.2134/jeq2003.6420
- Author:
- M. D. Tomer, et al. ; B. E. Clothier; I. Vogeler; S. Green; Show all 4 Authors
- Source:
- Soil Science Society of America journal 1999 v.63 no.4 pp. 777-781
- ISSN:
- 0361-5995
- Subject:
- air drying; bulk density; dielectric properties; equations; liquids; loamy sand soils; sandy loam soils; soil profiles; soil texture; soil water; soil water content; statistical models; tephra; time domain reflectometry; volcanic soils; New Zealand
- Abstract:
- ... To measure soil water content (θ) by time domain reflectometry (TDR), one must know the relationship between the soil's dielectric constant (K ₐ) and θ. Our objective was to determine K ₐ–θ calibrations for sandy volcanic soils on the North Island of New Zealand. We collected samples from 24 horizons and 6 soil profiles. The soils were sandy loam and loamy sand textured, with bulk densities betwee ...
- DOI:
- 10.2136/sssaj1999.634777x
- https://doi.org/10.2136/sssaj1999.634777x
- Author:
- M. D. Tomer, et al. ; J. L. Anderson; Show all 2 Author
- Source:
- Soil Science Society of America journal 1995 v.59 no.4 pp. 1091-1100
- ISSN:
- 0361-5995
- Subject:
- upland soils; topography; soil heterogeneity; soil water; storage; soil profiles; layered soils; Minnesota
- Abstract:
- ... Although landscape variations in soil properties and productivity are often attributed to soil water conditions, landscape-scale studies of soil water are rare. This study describes variability of soil layering and soil water storage on a sand plain hillslope. According to a nested grid (with spacings from 2 to 16 m), soil cores were collected by horizon, and soil water profiles were measured with ...
- DOI:
- 10.2136/sssaj1995.03615995005900040021x
- https://doi.org/10.2136/sssaj1995.03615995005900040021x
- Author:
- M. D. TOMER, et al. ; J. L. ANDERSON; Show all 2 Author
- Source:
- Soil science 1995 v.159 no.2 pp. 90-98
- ISSN:
- 0038-075X
- Subject:
- sandy soils; neutron probes; soil water content; capacitance; soil water; sand; measurement
- Abstract:
- ... A soil water capacitance probe (C-probe) and a neutron probe (N-probe) were calibrated for a fine sand. Data obtained with both probes and by time domain reflectometry (TDR) were compared. Calibrations were linear for the N-probe (R = 0.97), and quadratic for the C-probe (R = 0.92), based on 30 samples varying from 0.03 to 0.30 volumetric water content. N-probe-measured water contents were better ...
- DOI:
- 10.1097/00010694-199502000-00002
- https://doi.org/10.1097/00010694-199502000-00002
- Author:
- M. D. Tomer, et al. ; A. H. Ferguson; Show all 2 Author
- Source:
- Soil Science Society of America journal 1989 v.53 no.1 pp. 305-308
- ISSN:
- 0361-5995
- Subject:
- cement; concrete; desorption; disturbed soils; drainage; evaporation; latex; liquids; poly(vinyl chloride); rubber; soil sampling; vermiculite; water flow
- Abstract:
- ... A method of collection of minimally disturbed soil cores for use in laboratory studies is described. Cores were obtained with a standard soil sampling tube. The cores were then centered in a larger diameter PVC tube and covered with a liquid rubber latex molding compound that dries to a form fitting layer around the sample. The latex was covered with a thin layer of wax to prevent evaporation and ...
- DOI:
- 10.2136/sssaj1989.03615995005300010058x
- https://doi.org/10.2136/sssaj1989.03615995005300010058x