Refereed Articles

Refereed journal articles are those papers published by a major journal in the field, but which must first pass through the professional review process. Because these papers are examined by leading authorities in the field, their writing, presentation, and, most importantly, fundamental science are assured.

  1. Daigh, A.L.M., W.A. Dick, M.J. Helmers. R. Lal, J.G. Lauer, E. Nafziger, C.H. Pederson, J. Strock, M. Villamil, A. Mukherjee, and R. Cruse. In Press. Yields and yield stability of no-till and chisel-plow fields in the Midwestern U.S. Corn Belt. Field Crops Research Accepted April 2017.
  2. Anwar, U., L.A. Schulte, M.J. Helmers, and R.K. Kolka. 2017. The effect of five biomass cropping systems on soil saturated hydraulic conductivity across a topographic gradient. Bioenergy Research DOI 10.1007/s12155-017-9843-6.
  3. Schott, L.*, A. Lagzdins, A.L.M. Daigh, C. Pederson, G. Brenneman, and M.J. Helmers. In Press. Impact of drainage water management on the planting date of corn in Southeast Iowa. Journal of Soil and Water Conservation Accepted April 2017.
  4. Grudens-Schuck, N., M.J. Helmers, T.D. Youngquist, and M.S. Johnson. 2017. Prairie strips for sediment and nutrient control and biodiversity. Journal of Extension 55(1) Article 1TOT6. Available at: https://www.joe.org/joe/2017february/tt6.php
  5. Dziubanski, D.J., K.J. Franz, and M.J. Helmers. In press. Effects of spatial orientation of prairie vegetation in an agricultural landscape on curve number values. Journal of the American Water Resources Association Accept January 2017.
  6. Schott, L.*, A. Lagzdins, A.L.M. Daigh, K. Craft, C. Pederson, G. Brenneman, and M.J. Helmers. 2017. Effects of drainage water management on yield, drainage, water table, and volumetric water content in Southeast Iowa. Journal of Soil and Water Conservation 72(3): 251-259.
  7. Han, G., Y.R. Kandel, L.F.S. Leandro, M.J. Helmers, L.R. Schott*, and D.S. Mueller. 2017. Influence of drainage on soybean seedling health. Journal of Soil and Water Conservation 72(3): 266-271.
  8. Du, X. H. Feng, M.J. Helmers, and Z. Qi. In press. Comparing simulated nitrate-nitrogen concentration in subsurface drainage using DRAINMOD N-II and RZWQM2. Irrigation and Drainage Accepted December 2016.
  9. Araldi-Da-Silva G., T. Kaspar, M.J. Helmers, D. Mueller, and L. Leandro. 2016. Study of the influence of winter rye on soybean seedling and root rot diseases. Phytopathology 106:78-78.
  10. Martinez-Feria R.A., R. Dietzel, M Liebman, M.J. Helmers, S.V. Archontoulis. 2016. Rye cover crop effects on maize: A system-level analysis. Field Crops Research 196:145-159. DOI: 10.1016/j.fcr.2016.06.016.
  11. Dietzel, R., M. Liebman, R. Ewing, M.J. Helmers, R. Horton, M. Jarchow, and S. Archontoulis. 2016. How efficiently do corn- and soybean-based cropping systems use water? A systems modeling analysis. Global Change Biology 22(2): 666-681.
  12. Schulte, L., A.L. MacDonald, J.B. Niemi, and M.J. Helmers. 2016. Prairie strips as a mechanism to promote land sharing by birds in industrial agricultural systems. Agriculture, Ecosystems, and Environment 220:55-63.
  13. Doudna, J., M.E. O’Neal, J.C. Tyndall, and M.J. Helmers. 2015. Perspectives of Extension agents and farmers toward multifunctional agriculture in the United States corn belt. Journal of Extension 53(6): 6RIB5.
  14. Tomer, M.D., S.A. Porter, K.M.B. Boomer, D.E. James, J.A. Kostel, M.J. Helmers, T.M. Isenhart, and  E. McLellan. 2015. Agricultural Conservation Planning Framework: 1. Developing multipractice watershed planning scenarios and assessing nutrient reduction potential. Journal of Environmental Quality 44:754-767.
  15. Dosskey, M.G., S. Neelakantan, T.G. Mueller, T. Kellerman, M.J. Helmers, and E. Rienzi. 2015. AgBufferBuilder: A geographic information system (GIS) tool for precision design and performance assessment of filter strips. Journal of Soil and Water Conservation 70:209-217.
  16. Andersen, D.S., M.J. Helmers, and R.T. Burns. 2015. Phosphorus sorption capacity of six Iowa soils before and after five years of use as vegetative treatment areas. Applied Engineering in Agriculture 31(4): 611-620.
  17. Goeken, R.*, X. Zhou*, and M.J. Helmers. 2015. Comparison of timing and volume of subsurface drainage under perennial forage and row crops in a tile-drained field in Iowa. Trans. ASABE 58(5): 1193-1200.
  18. Daigh, A.L., X. Zhou, M.J. Helmers, C. Pederson, R. Horton, M. Jarchow, and M. Liebman. 2015. Subsurface drainage nitrate and total reactive phosphorus losses in bioenergy-based praries and corn systems. Journal of Environmental Quality 44(5): 1638-1646.
  19. Qi, Z.*, R. Singh*, M.J. Helmers, and X. Zhou*. 2015. Evaluating the performance of DRAINMOD using soil hydraulic parameters derived by various methods. Agricultural Water Management 155:48-52.
  20. Chen, B., W.F. Krajewski, X. Zhou, and M.J. Helmers. 2015. Organized variability of surface runoff processes across neighboring hillslopes in Iowa. Journal of Hydrology 523: 1-13.
  21. Wang, Z., Z. Qui, L. Xue, M. Bukovsky, and M.J.Helmers.  In press. Modeling the impacts of climate change on nitrogen losses and crop yield in a  subsurface drained field.  Accepted January 2015 to Climate Change.
  22. Iqbal, J., M. Castellano, M.J.Helmers, T. Parkin, and X. Zhou.  In press. Denitrification and N2O emissions in annual croplands, perennial grass buffers and restored perennial grasslands.  Accepted October 2014 to Soil Science Society of America Journal.
  23. Mitchell, D., X. Zhou*, T. Parkin, M.J. Helmers, and M. Castellano. 2015. Comparing nitrate sink strength in perennial filter strips at toeslope of cropland watersheds.  Journal of Environmental Quality 44(1) 191-199.
  24. Kladivko, E.J., M.J. Helmers, L.J. Abendroth, D. Herzmann, R., Lal, M. Castellano, D.S.Mueller, J.E. Sawyer, R.P. Anex, R.W.Arritt, B.Basso, J.V.Bonta, L.Bowling, R.M.Cruse, N.R.Fausey, J.Frankenberger, P.Gassman, A.J.Gassman, C.L.Kling, A.Kravchenko, J.G.Lauer, F.E.Miguez, E.D.Nafziger, N.Nkongolo, M.O'Neal, L.B.Owens, P.Owens, P. Scharf, M.J.Shipitalo, J.S.Strock, and M.B.Villamil.  2014. In press.  Standardized research protocols and database development for transdisciplinary understanding of corn systems and climate.  Accepted to Journal of Soil and Water Conservation.
  25. Necpalova, M., R.P.Anex, A.N.Kravchenko, L.J.Abendroth, S.J.DelGrosso, W.A.Dick, M.J.Helmers, D.Herzmann, E.J.Kladivko, J.G.Lauer, E.D.Nafziger, J.E.Sawyer, P.CScharf, J.Strock, and M.B.Villamil.  2014.  What does it take to detect a change in soil carbon stock?  A regional comparison of minimum detectable difference and experiement duration in the North Central United States.  Jounal of Soil and Water Conservation 69(6):  517-531.
  26. Daigh,A.L., M.J.Helmers, E.Kladivko, X.Zhou*, R.Goeken*, J.Cavadini, D.Barker, and J.Sawyer.  2014   Soil water during the drought of 2012 as affected by rye cover crops in fields in Iowa and Indiana.  Journal of Soil an dWater Conservation 69(6);564-573.
  27. Cox,R., M.O'Neal, R.Hessel, L.Schulte, and M.J.Helmers. 2014.  The impact of prairie strips on aphidophagous predator abundance and soybean aphid predation in agricultural catchments.  Environmental Entomology43(5):  1185-1197.
  28. Smith, T.W., R.K.Kolka, X.Zhou*, M.J.Helmers, R.M.Cruse, and M.D.Tomer. 2014.  Effects of native perennial vegetation buffer strips on dissolved organic carbon in surface runoff from an agricultural landscape.  Biogeochemistry 120(1-3):121-132.
  29. Andersen,D.S.*, R.T.Burns, M.J.Helmers, and L.B.Moody.  2014.  Vegetative treatment systems impacts on groundwater quality. Trans. of ASABE 57(2):417-430.
  30. Gutierrez-Lopez,J.*, H.Asbjornsen, M.J.Helmers, and T.Isenhart.  2014.  Regulation of soil moisture dynamics in agricultural fields using strips of native prairie vegetation.  Geoderma 226: 238-249.
  31. Jordan, N., L. Schulte-Moore, C. Williams, D. Mulla, D. Pitt, C. Schively-Slotterback, R. Jackson, D. Landis, B. Dale, D. Becker, M. Rickenbach, M.J. Helmers, and R. Bringi.  An integrated approach to creating agricultural enterprises that meet the triple bottom line.  2014. Journal of Higher Education Outreach and Engagement 17(4): 155-174.
  32. Perez-Suarez, M., M. Castellano, R.Kolka, H. Asbjornsen, and M.J. Helmers. 2014.  Nitrogen retention and availability in prairie vegetation strips across topographic gradients in mixed annual-perennial agroecosystems in Central Iowa, USA. 2014. Agriculture, Ecosystems and Environment DOI: 10.1016/j.agee.2014.01.023.
  33. Daigh, A.L., X. Zhou, M.J. Helmers, C.H.Pederson, R. Horton, and R. Ewing. 2014. Subsurface drainage flow and soil water dynamics of reconstructed prairies and corn rotations for biofuel production.  Vadose Zone Journal doi:10.2136/vzj2013.10.0177.
  34. Christianson, L.*, J.Tyndall, and M.J. Helmers. 2013. Financial comparison of seven nitrate reduction strategies for Midwestern agricultural drainage. Water Resources and Economics 2-3: 30-56.
     
  35. Christianson, L.*, T. Knott, D. Larsen, J.Tyndall, and M.J. Helmers. 2013. An ecosystems services approach to farmer adoption potential of drainage water quality improvement strategies. International Journal of Agricultural Sustainability DOI:  10.1080/14735903.2013.835604.
     
  36. Zhou, X.*, M.J. Helmers, H. Asbjornsen, R. Kolka, M. Tomer, and R. Cruse. 2013. Nutrient removal by prairie filter strips in agricultural landscape. Journal of Soil and Water Conservation 69(1):54-64.
     
  37. Zhou, X.*, M.J. Helmers, Z. Qi. 2013. Field scale modeling of subsurface tile drainage using MIKE SHE. Applied Engineering in Agriculture 29(6):865-873.
     
  38. Tyndall, J.C., L. Schulte, M. Liebman, and M.J. Helmers. 2013. Field-level financial assessment of contour prairie strips for environmental quality enhancement. Environmental Management 52(3):736-747.
     
  39. Zhao, X., X. Chen, J. Huang, P. Wu, and M.J. Helmers. 2013. Effects of vegetation cover of natural grassland on runoff and sediment yield on loess hilly region of China. Journal of the Science of Food and Agriculture DOI: 10.1002/jsfa.6275.
     
  40. Christianson, L.*, R. Christianson*, M.J. Helmers, C. Pederson, and A. Bhandari. 2013. Modeling and calibration of drainage denitrification bioreactor design criteria. Journal of Irrigation and Drainage Engineering 139: 699-709.
     
  41. Andersen, D.S.*, R.T. Burns, L.B. Moody, M.J. Helmers, B. Bond, I. Khanijo, and C. Pederson. 2013. Impact of system management on vegetative treatment system effluent concentrations. Journal of Environmental Management 125: 55-67.
     
  42. Liebman, M., M.J. Helmers, L.A. Schulte, and C.A. Chase. 2013. Using biodiversity to link agricultural productivity with environmental quality: Results from three field experiments in Iowa. Renewable Agriculture and Food Systems 28(2): 115-128.
     
  43. 10. Asbjornsen, H., V. Hernandez-Santana, M. Liebman, J. Bayala, J. Chen, M.J. Helmers, C.K. Ong, and L.A. Schulte-Moore. 2013. Targeting perennial vegetation in agricultural landscapes for enhancing evosystem services. Accepted to Renewable Agriculture and Food Systems DOI: 10.1017/S1742170512000385.
     
  44. Hernandez-Santana, V., X. Zhou*, M.J. Helmers, H. Asbjornsen, R. Kolka, and M. Tomer. 2013. Native prairie filter strips reduce runoff from hillslopes under annual row-crop systems in Iowa, USA. Journal of Hydrology 477:94-103.
     
  45. Christianson, L.*, M.J. Helmers, A. Bhandari, and T. Moorman. 2013. Internal hydraulics of an agricultural drainage denitrification bioreactor. Ecological Engineering 51: 298-307.
     
  46. Zhao, X., P. Wu, X. Chen, M.J. Helmers, and X. Zhou. 2013. Runoff and sediment yield under simulated rainfall on hillslopes in the Loess Plateau of China. Soil Research 51(1): 50-58.
     
  47. Christianson, L.,*, N. Hoover, a. Bhandari, and M.J. Helmers. 2012. Technical note: The potential of municipal yard waste to be denitrification bioreactor fill. Applied Engineering in Agriculture 26(5): 849-854.
     
  48. Christianson, L.*, a. Bhandari, and M.J. Helmers. 2012. A practice-oriented review of woodchip bioreactors for agricultural drainage. Applied Engineering in Agriculture 28(6): 861-874.
     
  49. Christianson, L.*, a. Bhandari, M.J. Helmers, K. Kult, T. Sutphin, and R. Wolf. 2012. Performance evaluation of four field-scale agricultural drainage denitrification bioreactors in Iowa. Trans. ASABE 55(6): 2163-2174.
     
  50. Helmers, M.J., R. Christianson*, g. Brenneman, D. Lockett*, and C. Pederson. 2012. Water table, drainage, and yield response to drainage water management in southeast Iowa. Journal of Soil and Water Conservation 67(6): 495-501.
     
  51. Helmers, M.J., X. Zhou*, H. Asbjornsen, R. Kolka, M.D. Tomer, and R. Cruse. 2012. Sediment removal by perennial filter strips in row-cropped ephemeral watersheds. Journal of Environmental Quality 41(5): 1531-1539.
     
  52. Helmers, M.J., X. Zhou*, J.L. Baker, S.W. Melvin, and D.W. Lemke. 2012. Nitrogen loss on tile-drained Mollisols as affected by nitrogen application rate under continuous corn and corn/soybean rotation systems. Canadian Journal of Soil Science 92: 493-499.
     
  53. Niu, W., Q. Guo, X. Zhou, and M.J. Helmers. 2012. Effect of aeration and soil water redistribution on the air permeability under subsurface drip irrigation. Soil Science Society of America Journal 76(3): 815-820.
     
  54. Qi, Z.*, L. Ma, M.J. Helmers, L.R. Ahuja, and R.W. Malone. 2012. Simulating nitrate-nitrogen concentration from a subsurface drainage system in response to nitrogen application rates using RZWQM2. Journal of Environmental Quality 41: 289-295. [Short Communication]
     
  55. Qi, Z.*, s. Feng, and M.J. Helmers. 2012. Modeling cadmium transport in neutral and alkaline soil columns at various depths. Pedosphere 22(3): 273-282.
     
  56. Lammers, P.J., M.D. Kenealy, J.B. Kliebenstein, J.D. Harmon, M.J. Helmers, and M.S. Honeyman. 2012. energy use in pig production: an examination of current Iowa systems. Journal of Animal Science 90(3): 1056-1068.
     
  57. Schilling, K., P. Jindal, N. Basu, and M.J. Helmers. 2011. Impact of artificial subsurface drainage on groundwater travel times and baseflow discharge in an agricultural watershed, Iowa (USA). Hydrological Processes 26(20): 3092-3100.
     
  58. Andersen, D.S.*, R.T. Burns, L.B. Moody, and M.J. Helmers. 2011. Using total solids concentration to estimate nutrient content of feedlot runoff effluent from solid settling basins, vegetative infiltration basins, and vegetative treatment areas. Applied Engineering in Agriculture 27(5): 803-810.
     
  59. Lawlow, P.A.*, M.J. Helmers, J.L. Baker, S.W. Melvin, and d.W. Lemke. 2011. Comparison of liquid swine manure and ammonia nitrogen applicaiton timing on subsurface drainage water quality in Iowa. Trans. ASABE 54(3): 973-981.
     
  60. Qi, Z.*, M.J. Helmers, R. Malone, and K. Thorp. 2011. Simulating long-term impacts of winter rye cover crop on hydrologic cycling and nitrogen dynamics of a corn-soybean crop system. Trans. ASABE 54(5): 1575-1588.
     
  61. Dosskey, M.G., Z. Qi, M.J. Helmers, and D.E. Eisenhauer. 2011. Improved indexes for targeting placement of buffers of Hortonian runoff. Journal of Soil and Water Conservation 66(6): 362-372.
     
  62. Qi, Z.*, M.J. Helmers, R.D. Christianson, and C.H. Pederson, 2011. Nitrate-nitrogen losses through subsurface drainage under various agricultural land covers. Journal of Environmental Quality 40: 1578-1585.
     
  63. Dosskey, M.G., M.J. Helmers, and D.E. Eisenhauer. 2011. A design aid for sizing filter strips using buffer area ratio. Journal of Soil and Water Conservation 66(1): 29-39.
     
  64. Qi, Z.*, M.J. Helmers, and A. Kaleita. 2011. Soil water dynamics under various land covers in Iowa. Agricultural Water Management 98(4): 665-674.
     
  65. Stenback, G., W. Crumpton, K. Schilling, and M.J. Helmers. 2011. Rating curve estimation of nutrient loads in Iowa rivers. Journal of Hydrology 396: 158-169.
     
  66. Christianson, L., a. Bhandari, and M.J. Helmers. 2011. Pilot-scale evaluation of denitrification drainage bioreactors: Reactor geometry and peformance. Journal of Environmental Engineering 137(4): 213-220.
     
  67. Bond, B.J.*, R.T. Burns, C.G. Henry, T.P. Trooien, S.H. Pohl, L.B. Moody,M.J. Helmers, and J.D. Lawrence. 2011. Comparison of construction costs for vegetative treatment systems in the Midwestern United Stated. Applied Engineering in Agriculture 27(3): 413-423.
     
  68. Lammers, P.J., M.S. Honeyman, J.D. Harmon, and M.J. Helmers. 2010. Energy and carbon inventory of Iowa swine production facilities. Agricultural Systems 103:551-561.
     
  69. Zhous, X*, M.J. Helmers, H. Asbjornsen, R. Kolka, and M. Tomer. 2010. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion. Journal of Environmental Quality 39(6): 2006-2015.
     
  70. Perez-Bidegain, M.*, M.J. Helmers, and R. Cruse. 2010. Modeling phosphorus transport in an agricultural watershed using the WEPP model. Journal of Environmental Quality 39(6): 2121-2129.
     
  71. Christianson, L., A. Castello, R. Christianson, A. Bhandari, and M.J. Helmers. 2010. Hydraulic property determination of denitrifying bacteria fill media. Applied Engineering in Agriculture 26(5): 849-854.
     
  72. Andersen, D.S., R.T. Burns, L.B.Moody, M.J. Helmers, R. Horton, and C. Pederson. 2010. Use of the Soil-Plant-Air-Water model to predict hydraulic performance of vegetative treatment areas for controlling open lot runoff. Trans. ASABE 53(2): 537-543.
     
  73. Arora, K., S.K. Mickeson, M.J. Helmers, and J.L. Baker. 2010. Review of pesticide retention process occurring in buffer strips receiving agricultural runoff. Journal of the American Water Resources Association 46(3): 618-647.
     
  74. Gassman, P.W., J.Tisl, E. Palas, C.L. Fields, T.M. Isenhart, K. Schilling, C. F. Wolter, L.S. Seigley, and M. J. Helmers. 2010. Conservation practice establishment in two northeast Iowa watersheds: Strategies, water quality implications, and lessons learned. Journal of Soil and Water Conservation 65(6): 381-392.
     
  75. Qi, Z.* and M.J. Helmers. 2010. The conversion of permittivity as measured by a PR2 capacitance probe into soil moisture values for Des Moines Lobe soils in Iowa. Soil Use and Management 26(1): 82-92.
     
  76. Andersen, D.S., R.T. Burns, L.B. Moody, M.J. Helmers, and R. Horton. 2010. Comparison of the Iowa State University-Effluent limitation guidelines model with the Soil-Plant-Air-Water model for evaluating containment basin performance. Trans. ASABE 53(1): 207-217.
     
  77. Lammers, P.J., M.D. Kenealy, J.B. Kleibenstein, J.D. Harmon, M.J. Helmers, and M.S. Honeyman. 2010. Non-solar energy use and 100-year global warming potential of Iowa swine feedstuffs and feeding strategies. Journal of Animal Science 88:1204-1212.
     
  78. Qi, Z.* and M.J. Helmers. 2010. Soil water dynamics under winter rye cover crop in central Iowa. Vadose Zone Journal 9(1): 53-60.
     
  79. Zhou, X.*, M. Al-Kaisi, and M. J. Helmers. 2009. Environmental and economic benefits of conservation practices in Iowa: Soil formation an darea specific evaluation study. Soil and Tillage Research 106(1): 71-78.
     
  80. Lammers. P.J., M.S. Honeyman, J.D. Harmon, J.B. Kliebenstein, and M.J. Helmers. 2009. Construction resource use of different types and scales of pig production facilities. Applied Engineeering in Agriculture 25(4): 585-593.
     
  81. Riley, K.D.*, M.J. Helmers, P.A. Lawlor, and R. Singh. 2009. Water balance investigation of controlled drainage in non-weighing lysimeters. Applied Engineering in Agriculture 25(4): 507-514.
     
  82. Zhou, X.*, M.J. Helmers, M. Al-Daisi, and H.M. Hann. 2009. Cost-benefit analysis of conservation management practices for sediment reduction in an Iowa agricultural watershed.Journal of Soil and Water Conservation 64(5): 314-323.
     
  83. Roberts, A., M.J. Helmers, I. Fillery. 2009. the adoptability of perennial-based farming systems for hydrologic and salinity control in dryland farming systems in Australia and the United States. Crop & Pasture Science 60: 83-99.
     
  84. Singh, R.*, M.J. Helmers, A.L. Kaleita, and E.S. Takle. 2009. Potential impact of climate change on subsurface drainage in Iowa's subsurface drained landscapes. Journal of Irrigation and Drainage Engineering 135(4): 459-466.
     
  85. Tomer, M.D., M.G. Dosskey, M.r. Burkart, d.e. James, M.J. Helmers, and D.E. Eisenhauer. 2009. Methods to prioritize placement of riparian buffers for improved water quality. Agroforestry Systems 75(1): 17-25.
     
  86. Asbjornsen, H., G. Shepherd*, M.J. Helmers, and G. Mora. 2008. Seasonal patterns in depth of water uptake under contrasting annual and perennial systems in the Corn Belt Region of the Midewestern U.S. Plant and Soil 308: 69-92.
     
  87. Schilling, K.E., and M.J. Helmers. 2008. effects of subsurface drainage tiles on streamflow in agricultural watershed: exploratory hydrograph analysis. Hydrological Processes 22(23): 4497-4506.
     
  88. Lawlor, P.A.*, M.J. Helmers, J.L. Baker, S.W. Melvin, and D.W. Lemke. 2008. Nitrogen application rate effects on nitrate-nitrogen concentrations and losses in subsurface drainage.Trans. ASABE 51(1): 83-94.
     
  89. Dosskey, M.D., M.J. Helmers, and D.E. Eisenhauer. 2008. A design aid for determining widths of filter strips. Journal of Soil and Water Conservation 63(4): 232-241.
     
  90. Schilling, K.E., and M.J. Helmers. 2008. Tile drainage as Karst: Conduit flow and diffuse flow in a tile-drained watershed. Journal of Hydrology 349: 291-301.
     
  91. M.J. Helmers, T.M. Isenhart, C.L. Kling, T.B. Moorman, W.W. Simpkins, and M. Tomer. 2007. Theme overview: Agriculture and water quality in the Corn Belt: Overview of issues and approaches. Choices 22(2): 79-84.
     
  92. Singh, R.*, M.J. Helmers, W.G. Crumpton, and D. W. Lemke. 2007. Predicting effects of drainage water management in Iowa's subsurface drained landscapes. Agricultural Water Management 92: 162-170.
     
  93. Asbjornsen, H., G. Mora, and M.J. Helmers. 2007. Variation in depth of water uptake in contrasting perennial an dannual ecosystems in central Iowa: Application of a multiple-source mass-balance isotope approach. Agriculture, Ecosystems, and Environment. 121: 343-356.
     
  94. Dosskey, M.G., M.J. Helmers, D.E. Eisenhauer, T.G. Franti, and K.D. Hoagland. 2006. An approach for using soil surveys to guide the placement of water quality buffers. Journal of Soil and Water Conservation 61(6): 344-354.
     
  95. Singh, R.*, M.J. Helmers, and Z. Qi. 2006. Calibration and validation of DRAINMOD to design subsurface drainage systems for Iowa's tile landscapes. Agricultural Water Management 85: 221-232.
     
  96. Helmers, M.J., and D.E. Eisenhauer. 2006. Overland flow modeling in a vegetative filter considering non-planar topography and spatial variability of soil hydraulic properties and vegetation density. Journal of Hydrology 328: 267-282.
     
  97. Dosskey, M.G., d.E. Eisenhauer, and M.J. Helmers. 2005. Establishing conservation buffers using precision information. Journal of Soil and Water Conservation 60(6): 349-354.
     
  98. Helmers, M.J., D.E. Eisenhauer, M.G. Dosskey, T.G. Franti, J. Brothers, and M.C. McCullough. 2005. flow pathways and sediment trapping in a field-scale vegetative filter. Trans ASAE 48(3): 955-968.
     
  99. Helmers, M.J., D.e. Eisenhauer, T.G. Franti, and M.G. Dosskey. 2005. Modeling sediment trapping in a vegetative filter accounting for converging overland flow. Trans. ASAE 48(2): 541-555.
     
  100. Dosskey, M.G., M.J. Helmers, D.E. Eisenhauer, T.G. Franti, and K.D. Hoagland. 2002. Assessment of concentrated flow through riparian buffers. Journal of Soil and Water Conservation 57(6): 336-343.

*MS, Ph.D., Post Doc, or Research Associate supervised by Helmers