Charles S. Wortmann

Charles S. Wortmann


·Atlas of Sorghum Production in Eastern & Southern Africa

Charles S. Wortmann


B.S. in Agronomy, University of Nebraska, 1972

M.S. in Soil Science, University of Nebraska, 1978

Ph.D. in Crop Science, University of Nebraska, 1987

Area of Focus

Soil Science


Sustainable Land Resource Management

High Yield Soybean Production

Explaining Statistical Analysis to Farmers

TOT in Uganda

Fighting Hunger in Africa

Optimizing Fertilizer Use in Uganda

Nitrogen Loss Assessment Tool (N-LAT)

Land Application of Novozyme Spent Biomass

Research Interests

Improved nitrogen and phosphorus management for improved nutrient use efficiency, water quality protection, and reduced nitrous oxide emissions in Nebraska's agriculture; and improving soil and water management for crop production in sub-Saharan Africa.

Major Project Activities

Research and extension for more profitable and environmentally safe nutrient management in Nebraska, and support to soil fertility management research and extension in sub-Saharan Africa.

Extension Interests

Soil fertility management, nutrient management planning, manure use, water quality protection, climate change issues, and optimizing fertilizer use in Africa.

Other Experience

Twenty years of agricultural research and extension experience in Africa; fluent in Swahili.


  • Kayuki C.K., J. Byalebeka, O. Semalulu, I. Alou, W. Zimwanguyizza, A. Nansamba, E. Odama, and C.S. Wortmann. 2014. Upland rice response to fertilizer in Uganda. Afr. J. Plant Sci. 8:416-425.
    Merga, F., K. Tesfaye, and C.S. Wortmann. 2014. Dry soil planting of sorghum for Vertisols of Ethiopia. Agron. J. 106:469-474
  • Jansen, J., C.S. Wortmann, M.C. Stockton, and K.C.Kaizzi. 2013. Maximizing net returns to financially constrained fertilizer use. Agron. J. 105:573-578.
  • Kaizzi, C.K., C. Wortmann, J. Byalebeka, O. Semalulu, I. Alou, W. Zimwanguyizza, A. Nansamba, P. Musinguzi, P. Ebanyat, T. Hyuha. 2011. Optimizing smallholder returns to fertilizer use: bean, soybean and groundnut. Field Crops Res. 127:109-119.
  • Abunyewa, Akwasi A., R.B. Ferguson, C. S. Wortmann, D. J. Lyon, S., C. Mason, S. Irmak. and R. N. Klein. 2011. Grain sorghum water use with skip-row configuration in the Central Great Plains of the USA. Afr. J. Agric. Res. 6:5328-5338.
  • Workayehu, T. and C.S. Wortmann. 2011. Maize-bean intercrop suppression of weeds and profitability in southern Ethiopia. Agron J. 104:1058-1063.
  • Wortmann, C.S., D.D. Tarkalson, C.A. Shapiro, A.R. Dobermann, R.B. Ferguson, G.W. Hergert, and D. Walters. 2010. Nitrogen use efficiency for three cropping systems in Nebraska. Agron. J. 103:76-84.
  • Dobermann, A., C.S. Wortmann, R.B. Ferguson, G.W. Hergert, C.A. Shapiro, D.D. Tarkalson, and D. Walters. 2010. Nitrogen Response and Economics for Irrigated Corn in Nebraska. Agron J. 103:67-75.
  • Wortmann, C.S., R. Drijber, and T.G. Franti. 2010. One-time tillage of no-till crop land five years post-tillage. Agron. J. 102:1302-1307.
  • Mesfin, T., G.B. Tesfahunegn, C.S. Wortmann, M. Mamo, and O. Nikus. 2010. Skip-row planting and tie-ridging for sorghum production in semi-arid areas of Ethiopia. Agron J. 102:745-750.
  • Abunyewa, A.A., R.B. Ferguson, C.S. Wortmann, D.J. Lyon, S.C. Mason, and R.N. Klein. 2010. Skip-row configuration and plant population effects on sorghum grain yield and yield stability in the Central Great Plains. Agron J. 102:296-302.
  • Wortmann, C.S., A.J. Liska, R.B. Ferguson, D.J. Lyon, R.N. Klein, and I. Dweikat. 2010. Dryland performance of sweet sorghum and grain crops for biofuel. Agron J 102:319-326.
  • Wortmann, C.S., M. Mamo, C. Mburu, E. Letayo, G. Abebe, K. C. Kayuki, M. Chisi, M. Mativavarira, S. Xerinda, T. Ndacyayisenga. 2009.  Atlas of sorghum (Sorghum bicolor (L.) Moench) production in eastern and southern Africa.
  • Mamo, M. and C. Wortmann, 2009. Phosphorus sorption as affected by soil properties and termite activity in eastern and southern Africa. SSSAJ 73:2170-2176.
  • Mesfin, T., G. B. Tesfahunegn, C.S. Wortmann, O. Nikus, and M. Mamo. 2009. Tie-ridging and fertilizer use for sorghum production in semi-arid Ethiopia. Nutr. Cycl. Agroecosys.
  • Wortmann, C.S., A.R. Dobermann, R.B. Ferguson, G.W. Hergert, C.A. Shapiro, D.D. Tarkalson, D. Walters. 2008. High yield corn response to applied phosphorus, potassium, and sulfur in Nebraska. Agron. J. 101 546-555
  • Brhane, G. and C.S. Wortmann. 2008. Tie-ridge tillage for high altitude pulse production in northern Ethiopia. Agron. J. 100:447-453.
  • Wortmann, C.S. and C.A. Shapiro. 2008. The effects of manure application on soil aggregation. J. Nutr. Cycling Agroecosystems 80:173-180.
  • Tarkalson, D.D., S.D. Kachman, J.M. Knops, J.E. Thies, and C.S. Wortmann. 2008. Decomposition of Bt and non- Bt corn hybrid residues in the field. Nutrient Cycling in Agroecosystems. 80:211-222.
  • Wortmann, C.S., J.A. Quincke, R.A. Drijber, M. Mamo, T. Franti. 2007. Soil microbial change and recovery after one-time tillage of continuous no-till. Agron. J. 100:1681-1686.
  • Wortmann, C.S. and D.A. Walters. 2007. Residual effects of compost and plowing on phosphorus and sediment in runoff. J. Envir. Qual. 36:1521-1527.
  • Quincke, J.A., C.S. Wortmann, M. Mamo, T.G. Franti, R.A. Drijber, and J.P. Garcia. 2007. One-time tillage of no-till systems: soil physical properties, phosphorus runoff, and crop yield. Agron. J. 99:1104-1110.
  • Quincke, J.A., C.S. Wortmann, M. Mamo, T. Franti, and R.A. Drijber. 2007. Occasional tillage of no-till systems: CO2 flux and changes in total and labile soil organic carbon. Agron. J. 99:1158-1168.
  • Garcia, J.P., C.S. Wortmann, M. Mamo, R. A. Drijber, J.A. Quincke, and D. Tarkalson.2007. One-time tillage of no-till: effects on nutrients, mycorrhizae, and phosphorus uptake. Agron. J. 99:1093-1103.
  • Kaizzi, C.K., J. Byalebeka, C.S. Wortmann, and M. Mamo. 2007. Low input approaches for soil fertility management in semi-arid eastern Uganda. Agron. J. 99: 847-853.
  • Wortmann, C.S., M. Mamo, and A. Dobermann. 2007. Nitrogen response of grain sorghum in rotation with soybean. Agron. J. 99:808-813.
  • Wortmann, C.S. 2007. Soil and water summaries for 2005 to 2006. NebGuide G1719, University of Nebraska-Lincoln.
  • Wortmann, C.S., M. Al-Kaisi, J. Sawyer, M. Helmers, D. Devlin, c. Barden, P. Scharf, R. Ferguson, C.A. Shapiro, R. Spalding, D. Tarkalson, W. Kranz, J. Holz, D. Francis, J. Schepers. Agricultural nitrogen management for water quality protection in the Midwest. University of Nebraska RP 189.
  • Wortmann, C. 2006. Phaseolus vulgaris L. (common bean). In: Brink, M. & Belay, G. (Ed). Plant Resources of Tropical Africa 1. Cereals and Pulses. PROTA Foundation, Wageningen, Netherlands / Blackhuys Publishers, Leiden, Netherlands / CTA, Wageningen, Netherlands. Pp 146-151.
  • Wortmann, C.S. and D. Walters. 2006. Phosphorus runoff during four years following composted manure application. J. Environ. Qual. 35: 651-657.
  • Brhane, G., C.S. Wortmann, M. Mamo, H. Gebrekidan, and A. Belay. 2006. Micro-basin tillage for grain sorghum production in semi-arid areas of northern Ethiopia. Agronomy Journal 98:124-128.
  • Wortmann, C.S., S.A. Xerinda, M. Mamo and C.A. Shapiro. 2006. No-till row crop response to starter fertilizer in eastern Nebraska: I. irrigated and rainfed corn. Agronomy Journal 98:156-162.
  • Wortmann, C.S., M. Helmers, A. Mallarino, C. Barden, D. Devlin, G. Pierzynski, J. Lory, R. Massey, J. Holz, C. Shapiro, J. Kovar. 2006. Agricultural phosphorus management and water quality protection in the Midwest. RP 187. University of Nebraska-Lincoln Extension.
  • Wortmann, C.S., A. P. Christiansen, K. L. Glewen, T.A. Hejny, J. Mulliken, J.M. Peterson, D. L. Varner, S. Wortmann, G. L. Zoubek, 2005. Farmer research: project evaluation and guidelines for implementation. Renew Agric. Food Syst. 20:243-251.
  • Benning, J.L. and C.S. Wortmann, 2005. Phosphorus indexes in four Midwestern States: an evaluation of the differences and similarities. J. Soil Water Conserv. 60:221-227.
  • Wilhelm, W. and C.S. Wortmann, 2004. Tillage and rotation interactions for corn and soybean grain yield as affected by precipitation and air temperature. Agron. J. 96:425-432.