Research Project: Managing Carbon and Nutrients in Midwestern U.S. Agroecosystems for Enhanced Soil Health and Environmental Quality

Location: Soil, Water & Air Resources Research

Publications (Clicking on the reprint icon will take you to the publication reprint.)

Molecular composition and possible transformations of labile soil organic matter fractions in Mediterranean arable soils: Relevance and implications - (Peer Reviewed Journal)
Abdelrahman, H., Hofmann, D., Sleighter, R.L., Olk, D.C., Berns, A.E., Miano, T.M., Shaheen, S.M., Cocozza, C. 2023. Molecular composition and possible transformations of labile soil organic matter fractions in Mediterranean arable soils: Relevance and implications. Environmental Research. 232. https://doi.org/10.1016/j.envres.2023.116315.

Formation efficiency of soil organic matter from plant litter is governed by clay mineral type more than plant litter quality - (Peer Reviewed Journal)
Yuzhi, X., Liu, K., Yao, S., Zhang, Y., Zhang, X., He, H., Feng, W., Ndzana, G.M., Chenu, C., Olk, D.C., Mao, J., Bin, Z. 2022. Formation efficiency of soil organic matter from plant litter is governed by clay mineral type more than plant litter quality. Geoderma. 412. Article e115727. https://doi.org/10.1016/j.geoderma.2022.115727.

Maize growth responses to a humic product in Iowa production fields: An extensive approach - (Peer Reviewed Journal)
Olk, D.C., Dinnes, D.L., Callaway, C.R. 2022. Maize growth responses to a humic product in Iowa production fields: An extensive approach. Frontiers in Plant Science. 12. Article e778603. https://doi.org/10.3389/fpls.2021.778603.

Tree species of wet tropical forests differ in their tissue biochemistry and effects on soil carbon dynamics - (Database / Dataset)
Russell, A.E., Marek, R.F., Olk, D.C. 2021. Tree species of wet tropical forests differ in their tissue biochemistry and effects on soil carbon dynamics. Dryad Digital Repository. https://doi.org/10.5061/dryad.fbg79cntt.

Tree species of wet tropical forests differ in their tissue biochemistry and effects on soil carbon dynamics - (Peer Reviewed Journal)
Russell, A.E., Marek, R.F., Olk, D.C. 2021. Tree species of wet tropical forests differ in their tissue biochemistry and effects on soil carbon dynamics. Frontiers in Forests and Global Change. 4. Article 674213. https://doi.org/10.3389/ffgc.2021.674213.

Maize growth and grain yield responses to a micronized humic product across soil types and annual weather patterns in Central Iowa, United States - (Peer Reviewed Journal)
Olk, D.C., Dinnes, D.L., Scoresby, R.J., Darlington, G.W., Hurburgh, C.R., Rippke, G.R. 2021. Maize growth and grain yield responses to a micronized humic product across soil types and annual weather patterns in Central Iowa, United States. Frontiers in Plant Science. 12. Article 672078. https://doi.org/10.3389/fpls.2021.672078.

Soil texture and straw type modulate the chemical structure of residues during four-year decomposition by regulating bacterial and fungal communities - (Peer Reviewed Journal)
Li, D., Zhao, B., Olk, D.C., Zhang, J. 2020. Soil texture and straw type modulate the chemical structure of residues during four-year decomposition by regulating bacterial and fungal communities. Applied Soil Ecology. 155. Article 103664. https://doi.org/10.1016/j.apsoil.2020.103664.

Formation of char-like, fused-ring aromatic structures from a nonpyrogenic pathway during decomposition of wheat straw - (Peer Reviewed Journal)
Chen, X., Ye, X., Chu, W., Olk, D.C., Cao, X., Schmidt-Rohr, K., Zhang, L., Thompson, M.L., Mao, J., Gao, H. 2020. Formation of char-like, fused-ring aromatic structures from a nonpyrogenic pathway during decomposition of wheat straw. Journal of Agricultural and Food Chemistry. 68(9):2607-2614. https://doi.org/10.1021/acs.jafc.9b06037.

Changes in labile fractions of soil organic matter during the conversion to organic farming - (Peer Reviewed Journal)
Abdelrahman, H.M., Cocozza, C.C., Olk, D.C., Ventrella, D., Montemurro, F., Miano, T. 2020. Changes in labile fractions of soil organic matter during the conversion to organic farming. Journal of Soil Science and Plant Nutrition. https://doi.org/10.1007/s42729-020-00189-y.

Whole-profile soil organic matter content, composition, and stability under cropping systems that differ in belowground inputs - (Peer Reviewed Journal)
Poffenbarger, H.J., Olk, D.C., Cambardella, C.A., Kersey, J., Liebmann, M., Mallarino, A., Six, J., Castellano, M.J. 2020. Whole-profile soil organic matter content, composition, and stability under cropping systems that differ in belowground inputs. Agriculture, Ecosystems and Environment. 291. https://doi.org/10.1016/j.agee.2019.106810.

Long-Term benefits of humic product application to soil organic matter and physical properties in Iowa corn-soybean rotations - (Abstract Only)
Olk, D.C., Dinnes, D.L., Abdelrahman, H.M., Scoresby, R.J. 2019. Long-Term benefits of humic product application to soil organic matter and physical properties in Iowa corn-soybean rotations. In proceedings of ASA-SSSA-CSA Annual Meeting, Nov 10-13,2019, San Antonio, Texas. Available: https://scisoc.confex.com/scisoc/2019am/meetingapp.cgi/Paper/120820.

Soil health assessment: Past accomplishments, current activities, and future opportunities - (Peer Reviewed Journal)
Karlen, D.L., Veum, K.S., Sudduth, K.A., Obrycki, J.F., Nunes, M.R. 2019. Soil health assessment: Past accomplishments, current activities, and future opportunities. Soil & Tillage Research. 195(104356). https://doi.org/10.1016/j.still.2019.104365.

Corn root and soil health indicator response to no-till production practices - (Peer Reviewed Journal)
Nunes, M.R., Karlen, D.L., Denardin, J.E., Cambardella, C.A. 2019. Corn root and soil health indicator response to no-till production practices. Agriculture, Ecosystems and Environment. 285. https://doi.org/10.1016/j.agee.2019.106607.

Potential alterations in the chemical structure of soil organic matter components during sodium hydroxide extraction - (Peer Reviewed Journal)
Chen, X., Jin, M., Xu, Y., Chu, W., Olk, D.C., Hu, J., Jiang, Y., Mao, J., Gao, H., Thompson, M.L. 2019. Potential alterations in the chemical composition of soil organic matter during NaOH extraction. Journal of Environmental Quality. 48(6):1578-1586. https://doi.org/10.2134/jeq2019.02.0077.

Demonstration of chemical distinction among soil humic fractions using quantitative solid-state 13C NMR - (Peer Reviewed Journal)
Xu, J., Zhao, B., Li, Z., Chu, W., Mao, J., Olk, D.C., Zhang, J., Xin, X., Wei, W. 2019. Demonstration of chemical distinction among soil humic fractions using quantitative solid-state 13C NMR. Journal of Agricultural and Food Chemistry. 67(29):8107-8118. https://doi.org/10.1021/acs.jafc.9b02269.

Application of a formulated humic product can increase soybean yield - (Peer Reviewed Journal)
Lenssen, A.W., Olk, D.C., Dinnes, D.L. 2019. Application of a formulated humic product can increase soybean yield. Crop, Forage & Turfgrass Management. 5(1):1-6. https://doi.org/10.2134/cftm2018.07.0053.

Developments in agricultural soil quality and health: Reflections by the Research Committee on soil organic matter management - (Peer Reviewed Journal)
Wander, M.M., Cihacek, L.J., Coyne, M., Drijber, R.A., Grossman, J.M., Gutknecht, J.L., Horwath, W.R., Jagadamma, S., Olk, D.C., Ruark, M., Snapp, S.S., Tiemann, L.K., Weil, R., Turco, R.F. 2019. Developments in agricultural soil quality and health: Reflections by the Research Committee on soil organic matter management. Frontiers in Environmental Science. https://doi.org/10.3389/fenvs.2019.00109.

Using humic fractions to understand natural organic matter processes in soil and water: Selected studies and applications - (Peer Reviewed Journal)
Olk, D.C., Bloom, P.R., De Nobili, M., Chen, Y., McKnight, D.M., Wells, M.J.M., Weber, J. 2019. Using humic fractions to understand natural organic matter processes in soil and water: Selected studies and applications. Journal of Environmental Quality. 48(6):1633-1643. https://doi.org/10.2134/jeq2019.03.0100.

Can humic products substantially improve ecosystem quality and economic yield? - (Peer Reviewed Journal)
Olk, D.C., Dinnes, D.L., Scoresby, J.R., Callaway, C.R., Darlington, J.W. 2019. Can humic products substantially improve ecosystem quality and economic yield? Silva Balcanica. 20(1):95-110.

Nitrogen fertilizer suppresses mineralization of soil organic matter in maize agroecosystems - (Peer Reviewed Journal)
Mahal, N.K., Osterholz, W.R., Miguez, F.E., Poffenbarger, H.J., Sawyer, J.E., Olk, D.C., Archontoulis, S.V., Castellano, M.J. 2019. Nitrogen fertilizer suppresses mineralization of soil organic matter in maize agroecosystems. Frontiers in Ecology and Evolution. https://doi.org/10.3389/fevo.2019.00059.

Reanalysis confirms soil health indicator sensitivity and correlation with long-term crop yields - (Peer Reviewed Journal)

Environmental and agricultural relevance of humic fractions extracted by alkali from soils and natural waters - (Peer Reviewed Journal)
Olk, D.C., Bloom, P.R., Perdue, E.M., McKnight, D.M., Chen, Y., Farenhorst, A., Senesi, N., Chin, Y.P., Schmitt-Kopplin, P., Hertkorn, N., Harir, M. 2019. Environmental and agricultural relevance of humic fractions extracted by alkali from soils and natural waters. Journal of Environmental Quality. 48:217-232. https://doi.org/10.2134/jeq2019.02.0041.

Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil’s bioenergy industry? - (Peer Reviewed Journal)

The role of hydraulic connectivity and management on soil aggregate size and stability in the Clear Creek Watershed, Iowa - (Peer Reviewed Journal)
Wacha, K.M., Papanicolaou, A.N.T., Giannopoulos, C.P., Abban, B.K., Wilson, C.G., Zhou, S., Hatfield, J.L., Filley, T.R., Hou, T. 2018. The role of hydraulic connectivity and management on soil aggregate size and stability in the Clear Creek Watershed, Iowa. Geosciences. 8(12). https://doi.org/10.3390/geosciences8120470.

Chemical nature of soil organic carbon under different long-term fertilization regimes is coupled with changes in the bacterial community in a Calcaric Fluvisol - (Peer Reviewed Journal)
Li, D., Chen, L., Xu, J., Ma, L., Olk, D.C., Zhao, B., Zhang, J., Xin, X. 2018. Chemical nature of soil organic carbon under different long-term fertilization regimes is coupled with changes in the bacterial community in a Calcaric Fluvisol. Biology and Fertility of Soils. 54:999-1012. https://doi.org/10.1007/s00374-018-1319-0.

Soil health assessments: How and why? - (Popular Publication)
Karlen, D.L., Obrycki, J.F. 2019. Soil health assessments: How and why?. Crops and Soils. 52(2):22-57. https://doi.org/10.2134/cs2019.52.0210.

Ten-year assessment encourages no-till for corn grain and stover harvest - (Peer Reviewed Journal)
Obrycki, J.F., Kovar, J.L., Karlen, D.L., Birrell, S.J. 2018. Ten-year assessment encourages no-till for corn grain and stover harvest. Agricultural and Environmental Letters. 3:1800034. https://doi.org/10.2134/ael2018.06.0034.

Legacy effects of long-term nitrogen fertilizer application on the fate of nitrogen fertilizer inputs in continuous maize - (Peer Reviewed Journal)
Poffenbarger, H.J., Sawyer, J.E., Barker, D., Olk, D.C., Six, J., Castellano, M.J. 2018. Legacy effects of long-term nitrogen fertilizer application on the fate of nitrogen fertilizer inputs in continuous maize. Agriculture Ecosystems and the Environment. 265:544-555. https://doi.org/10.1016/j.agee.2018.07.005.

Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter - (Peer Reviewed Journal)
Cordova, S.C., Olk, D.C., Dietzel, R., Mueller, K., Archontouilis, S., Castellano, M. 2018. Plant litter quality affects the accumulation rate, composition, and stability of mineral-associated soil organic matter. Soil Biology and Biochemistry. 125:115-124. https://doi.org/10.1016/j.soilbio.2018.07.010.

Subsoil potassium in central Iowa soils: Status and future challenges - (Peer Reviewed Journal)
Obrycki, J.F., Kovar, J.L., Karlen, D.L. 2018. Subsoil potassium in central Iowa soils: Status and future challenges. Agrosystems, Geosciences & Environment. https://doi.org/10.2134/age2018.07.0018.

Optimizing Iowa land use: Past perspectives for current questions - (Peer Reviewed Journal)
Obrycki, J., Karlen, D.L. 2018. Optimizing Iowa land use: Past perspectives for current questions. Journal of Soil and Water Conservation. 73(6):693-704. https://doi.org/10.2489/jswc.73.6.693.

An Iowa on-farm carbon and soil health indicator assessment study - (Peer Reviewed Journal)
Karlen, D.L., Obrycki, J.F. 2018. An Iowa on-farm carbon and soil health indicator assessment study. Agronomy Journal. https://doi.org/10.2134/agronj2018.02.0113.

Corn stover harvest, tillage, and cover crop effects on soil health indicators - (Peer Reviewed Journal)
Obrycki, J.F., Karlen, D.L., Cambardella, C.A., Kovar, J.L., Birrell, S.J. 2018. Corn stover harvest, tillage, and cover crop effects on soil health indicators. Soil Science Society of America Journal. 82(4):910-918. https://doi.org/10.2136/sssaj2017.12.0415.

Distinct changes in composition of soil organic matter with length of cropping time in subsoils of a Phaeozem and Chernozem - (Peer Reviewed Journal)
Zhang, Y., Li, L., Mao, J., Yao, S., Schmidt-Rohr, K., Olk, D.C., Cao, X., Cui, J., Zhang, B. 2018. Distinct changes in composition of soil organic matter with length of cropping time in subsoils of a Phaeozem and Chernozem. European Journal of Soil Science. https://onlinelibrary.wiley.com/doi/pdf/10.1111/ejss.12688.

Contributions of residue-C and -N to plant growth and soil organic matter pools under planted and unplanted conditions - (Peer Reviewed Journal)
Li, Z., Zhao, B., Olk, D.C., Jia, Z., Mao, J., Cai, Y., Zhang, J. 2018. Contributions of residue-C and -N to plant growth and soil organic matter pools under planted and unplanted conditions. Soil Biology and Biochemistry. 120:91-104. https://doi.org/10.1016/j.soilbio.2018.02.005.

Is corn stover harvest predictable using farm operation, technology, and management variables? - (Peer Reviewed Journal)
Obrycki, J.F., Karlen, D.L. 2018. Is corn stover harvest predictable using farm operation, technology, and management variables? Agronomy Journal. 110:749–757. https://doi.org/10.2134/agronj2017.08.0504.

Humic products in agriculture: Potential benefits and research challenges-a review - (Peer Reviewed Journal)
Olk, D.C., Dinnes, D.L., Scoresby, R., Callaway, C.R., Darlington, J.W. 2018. Humic products in agriculture: Potential benefits and research challenges-a review. Journal of Soils and Sediments. 18:2881-2891. https://doi.org/10.1007/s11368-018-1916-4.

Nitrogen cycling under alternate wetting and drying cycles in Arkansas rice - (Abstract Only)

Forages for conservation and improved soil quality - (Book / Chapter)

Healthy soils healthy people: Unraveling the complexity - (Book / Chapter)
Cherubin, M.R., Souza, T.P., Karlen, D.L. 2017. Healthy soils healthy people: Unraveling the complexity. In: Monteiro, I., Iguti, A.M. editors. Work, Health and Sustainability: An Interdisciplinary International Dialogue South – North. Campinas, Brazil: UnicampBFCM. p. 187-192.

Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil - (Peer Reviewed Journal)
Xu, J., Zhao, B., Chu, W., Mao, J., Olk, D.C., Xin, X., Zhang, J. 2017. Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil. Science of the Total Environment. 601-602:356-364. doi: 10.1016/j.scitotenv.2017.05.205.

Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil - (Peer Reviewed Journal)
Xu, J., Zhao, B., Chu, W., Mao, J., Olk, D.C., Xin, X., Zhang, J. 2017. Altered humin compositions under organic and inorganic fertilization on an intensively cultivated sandy loam soil. Science of the Total Environment. 601-602:356-364. https://doi.org/10.1016/j.scitotenv.2017.05.205.

On-farm soil health evaluations: Challenges and opportunities - (Peer Reviewed Journal)
Karlen, D.L., Goeser, N., Veum, K.S., Yost, M.A. 2017. On-farm soil health evaluations: Challenges and opportunities. Journal of Soil and Water Conservation Society. 72(2):26A-31A. doi: 10.2489/jswc.72.2.26A.