
2543 Agronomy 716 Farm House Ln
(515) 294-7843
rhorton@iastate.edu

2543 Agronomy 716 Farm House Ln
(515) 294-7843
rhorton@iastate.edu
About
Robert Horton is a Distinguished Professor in the Agronomy Department at Iowa State University. His program addresses soil physical processes and soil physical properties, with a focus on coupled heat and mass transfer in soil. His fundamental work on coupled heat and mass transfer in soil has greatly enhanced understanding of the role of soils in the following topic areas: climatology (the importance of surface energy partitioning); water quality (the impacts of soil water and chemical movement); agricultural production (the impact of the soil environment on seed and root functions); ecosystem products and services (the impact of the soil environment on microbial function and gas exchange); and environmental investigations (thermal and mass flow methods for remediation of soil pollution). His singular contributions include a comprehensive theory of coupled heat, water and chemical transfer in soil, quantifying in situ unsaturated soil hydraulic conductivity and dynamic subsurface water evaporation, and devising and validating a method to control fertilizer nitrogen leaching. To reach these goals his program includes laboratory and field measurements, sensor development, theory development, and numerical modeling.
Awards
Graduated Magna cum laude, Texas A&M University (1975)
Outstanding technical reviewer for the Soil and Water Division of the American Society of Agricultural Engineers (1989)
Raymond and Mary Baker Agronomic Excellence Award (1989)
Iowa State University Foundation Award for Mid-Career Achievement in Research (1990)
Elected Chairman of Soil Physics Division of the Soil Science Society of America (1993)
Fellow of the American Society of Agronomy (1993)
Fellow of the Soil Science Society of America (1994)
Appointed Chairman of the Soil Science Faculty Committee at ISU (1995-2002)
Appointed to Agronomy Department Head’s Advisory Council (1995-2002)
Superior Paper Award of the American Society of Agricultural Engineers (1997)
Soil Science Research Award of the Soil Science Society of America (2001)
Don and Betty Kirkham Soil Physics Award of the Soil Science Society of America (2002)
CampbellLecturer, Washington State University (2004)
Frontiers of Hydrologic Sciences Lecturer, American Geophysics Union (2005)
Selected as Distinguished Professor, Iowa State University (2006)
Honorary Professor at China Agricultural University (2007)
Rossmann-Manatt Faculty Development Award, ISU (2009)
People
Publications
Dr. Horton on Google Scholar
Selected publications
1) Woche, S. K., M.-O. Goebel, M. B. Kirkham, R. Horton, R. R. van der Ploeg, and J. Bachmann. 2005. Contact angle of soils as affected by depth, texture, and land management. European J. Soil Sci. 56: 239-251.
2) Ochsner, T. E., R. Horton, G. J. Kluitenberg, and Q. Wang. 2005. Evaluation of the heat pulse ratio technique for measuring soil water flux. Soil Sci. Soc. Am. J. 69: 757-765.
3) Helmke, M.F., W.W. Simpkins, and R. Horton. 2005. Fracture-controlled transport of nitrate and atrazine in four Iowa till units. J. Environ. Qual. 34: 227-236.
4) Ren, T., Z. Ju, Y. Gong, and R. Horton. 2005. Comparing heat-pulse and TDR soil water contents from thermo-TDR probes. Vadose Zone J. 4: 1080-1086.
5) Gaur, A., R. Horton, and D. B. Jaynes. 2006. Measured and predicted solute transport in a tile drained field. Soil Sci. Soc. Am. J. 70: 872-881.
6) Ochsner, T. E., T. J. Sauer, and R. Horton. 2006. Field tests of the soil heat flux plate method and some alternatives. Agron. J. 98:1005-1014.
7) Al-Jabri, S.A., J. Lee, A. Gaur, R. Horton and D.B. Jaynes. 2006. A dripper-TDR method for in situ determination of hydraulic conductivity and chemical transport properties of surface soils. Adv. Water Resour. 29: 239-249.
8) Zhou, J., J. L. Heitman, R. Horton, T. Ren, T. E. Ochsner, L. Prunty, R. P. Ewing and T. J. Sauer. 2006. Method for maintaining one-dimensional temperature gradients in unsaturated, closed soil cells. Soil Sci. Soc. Am. J. 70:1303-1309.
9) Bachmann, J., G. Arye, M. Deuer, S. K. Woche, R. Horton, K. H. Hartge, and Y. Chen. 2006. Universality of a surface tension – contact angle relation for hydrophobic soils of different texture. J. Plant Nutr. Soil Sci. 169: 745-753.
10) Ilsemann, J., R.R. van der Ploeg, R. Horton, and D. Hermsmeyer. 2006. A semi-analytical model for solute transport in layered dual-porosity media. J. Plant Nutr. Soil Sci. 169: 754-761.
11) Ochsner, T. E., T. J. Sauer, and R. Horton. 2007. Soil heat storage measurements in energy balance studies. Agron. J. 99:311-319.
12) Sauer, T. J., T. E. Ochsner, and R. Horton. 2007. Soil heat flux plates: heat flow distortion and thermal contact resistance. Agron. J. 99:304-310.
13) Lu, S., T. Ren, Y. Gong, and R. Horton. 2007. An improved model for predicting room temperature soil thermal conductivity versus water content. Soil Sci. Soc. Am. J. 71:8- 14.
14) Kluitenberg, G. J., T. E. Ochsner, and R. Horton. 2007. Improved analysis of heat pulse signals for soil water flux determination. Soil Sci. Soc. Am. J. 71:53-55.
15) Heitman, J.L., A. Gaur, R. Horton, D.B. Jaynes, and T.C. Kaspar. 2007. Field measurement of soil surface chemical transport properties for comparison of management zones. Soil Sci. Soc. Am. J. 71:529-536.
16) Gaur, A., D. B. Jaynes, R. Horton, and T. E. Ochsner. 2007. Surface and subsurface solute transport properties at row and inter-row positions. Soil Sci. 172:419-431.
17) Heitman, J.L., R. Horton, T. Ren, and T.E. Ochsner. 2007. An improved approach for measurement of coupled heat and water transfer in soil cells. Soil Sci. Soc. Am. J. 71:872-880.
18) Wang, Q. and R. Horton. 2007. Boundary layer theory description of solute transport in soil. Soil Sci. 172:835–841.
19) Ewing, R.P. and R. Horton. 2007. Thermal conductivity of a cubic lattice of spheres with capillary bridges. J. Phys. D: Applied Physics 40: 4959–4965.
20) Liu, G., B. Li, T. Ren, and R. Horton. 2007. Analytical solution of heat pulse method in a parallelepiped sample space. Soil Sci. Soc. Am. J. 71: 1607-1619.
21) Heitman, J.L., R. Horton, T. Ren, I.N. Nassar, and D. Davis. 2008. A test of coupled soil heat and water transfer prediction under transient boundary conditions. Soil Sci. Soc. Am. J. 72: 1197–1207.
22) Gieselman, H., J.L. Heitman, and R. Horton. 2008. Effect of a hydrophobic layer on the upward movement of water under freezing conditions. Soil Sci. 173:297-305.
23) Liu, X., T. Ren, and R. Horton. 2008. Determination of soil bulk density with thermo-TDR sensors. Soil Sci. Soc. Am. J. 72: 1000-1005.
24) Heitman, J.L., R. Horton, T.J. Sauer, and T.M. DeSutter. 2008. Sensible heat observations reveal soil-water evaporation dynamics. J. Hydromet. 9:165-171.
25) Liu, G., B. Li, T. Ren, R. Horton, and B. C. Si. 2008. Analytical solution of heat pulse method in a parallelepiped sample space with inclined needles. Soil Sci Soc Am J. 72: 1208–1216.
26) Gao, Z., R. Horton, L. Wang, H. Liu, and J. Wen. 2008. An improved force-restore method for soil temperature prediction. European J. Soil Sci. 59: 972–981.
27) Sauer, T.J., O.D. Akinyemi, P. Thery, J.L. Heitman, T.M. DeSutter, and R. Horton. 2008. Evaluation of a new, perforated heat flux plate design. International Com. Heat Mass Transfer 35:800–804.
28) Lu, S., T. Ren, and Y. Gong, and R. Horton. 2008. Evaluation of models for describing soil water retention curve from saturation to oven dryness. Soil Sci. Soc. Am. J. 72:1542–1546.
29) Heitman, J. L., X. Xiao, R. Horton, and T. J. Sauer. 2008. Sensible heat measurements indicating depth and magnitude of subsurface soil water evaporation. Water Resour. Res., 44, W00D05, DOI 10.1029/2008WR006961.
30) Gao, Z., D. H. Lenschow, R. Horton, M. Zhou, L. Wang, and J. Wen. 2008. Comparison of two soil temperature algorithms for a bare ground site on the Loess Plateau in China. J. Geophys. Res., 113, D18105, DOI 10.1029/2008JD010285.
31) Ju, Z., T. Ren, and R. Horton. 2008. Influences of dichlorodimethylsilane treatment on soil hydrophobicity, thermal conductivity, and electrical conductivity. Soil Sci. 173: 425– 432.
32) Huo, Z., M.A.Shao, and R. Horton. 2008. Impact of gully on soil moisture of shrubland in wind-water erosion crisscross region of the Loess Plateau. Pedosphere 18: 674–680.
33) Wei, X., M. Shao, R. Horton, and X. Han. 2009. Humic acid transport in water-saturated porous media. Environ. Model. Assess. DOI 10.1007/s10666-008-9186-y.
34) Hu, W., M. Shao, Q. Wang, J. Fan, and R. Horton. 2009. Temporal changes of soil hydraulic properties under different land uses. Geoderma 149:355-366.
35) Lu, S., Z. Ju, T. Ren, and R. Horton. 2009. A general approach to estimate soil water content from thermal inertia. Agric. Forest Meteorol., DOI 10.1016/j.agrformet.2009.05.011.
36) Fu, X., M. Shao, X. Wei, and R. Horton. 2009. Effects of two perennials, fallow and millet on distribution of phosphorous in soil and biomass on sloping loess land, China. Catena 77:200–206.
37) Wei, X., M. Shao, X. Fu, R. Horton, Y. Li, and X. Zhang. 2009. Distribution of soil organic C, N and P in three adjacent land use patterns in the northern Loess Plateau, China. Biogeochemistry DOI 10.1007/s10533-009-9350-8.
38) Davis, D.D., R. Horton, J.L. Heitman, and T. Ren. 2009. Wettability and hysteresis effects on water sorption in relatively dry soil. Soil Sci. Soc. Am. J. 73:1947–1951.
39) Wang, Q., R. Horton, and J. Fan. 2009. An analytical solution for one-dimensional water infiltration and redistribution in unsaturated soil. Pedosphere 19:104–110.
40) Li , Y., R. Horton, T. Ren and C. Chen. 2009. Investigating time scale effects on reference evapotranspiration from Epan data in north China. J. Appl. Meteor. Climatol., DOI: 10.1175/2009JAMC2130.1.
41) Andersen, D.S., R.T. Burns, L.B. Moody, M.J. Helmers, and R. Horton. 2009. Comparison of the Iowa State University – effluent limitation guidelines model with the soil-plantair-water model for evaluating containment basin performance. Transactions ASAE. (in press).
42) Fu, X., M. Shao, X. Wei, and R. Horton. 2009. Soil organic carbon and total nitrogen as affected by vegetation types in Northern Loess Plateau of China. Geoderma (in press).
43) Wei, X., M. Shao, X. Fu, and R. Horton. 2009. Changes in soil organic carbon and total nitrogen after 28 years grassland afforestation: Effects of tree species, slope position and soil order. Plant and Soil (in press).
44) Wang, L., R. Horton, and Z. Gao. 2009. Comparison of six algorithms to determine the soil apparent thermal diffusivity at a site in the Loess Plateau of China. Soil Sci. (in press).