Santosh Shiwakoti

Ph.D Candidate

Office: 541-224-6766

Crop Science Building

Crop Science Building 417

3050 SW Campus Way

3050 SW Campus Way
Corvallis, OR 97331

Profile Field Tabs

Affiliated with: 
Crop Science
Major Professor: 
Academic Interests: 

My research is focussed on some of the long-term experiments (LTEs) at Columbia Basin Agriculture Research Center (CBARC), Pendleton, OR. I am studying the long-term effects of agricultural practices (crop residue incorporation, organic and inorganic amendments,  tillage types, and tillage intensities on plant and soil nutrients (nitrogen, phosphorus, potassium, sulfur, carbon, magnesium, calcium, manganese, copper, iron, boron, and zinc) in dryland winter wheat cropping system of Pacific Northwest. I will be analyzing soil and wheat (grain and straw) samples from 1995, 2005, and 2015 and compare it with the undisturbed grassland plots' soil samples from those years. My primary research question is whether all the above-mentioned practices are sustainable for a long term winter wheat production or not. Nutrients are one of the prime indicators of a good soil quality, and hence it is necessary to elucidate the dynamics of nutrients over the time influenced by the different agricultural practices.

I started my Ph.D. degree at University of Wyoming (UW) in 2013 and transferred to OSU in 2015. During my brief UW time, I conducted a field research on mints (spearmints, peppermints, Japanese corn mints). My another research was on three different types of season extension methods (low tunnel, high tunnel and low tunnel in a high tunnel) of vegetables and herbs production for Wyoming conditions.

During my MS at Auburn University, AL, I did a field and greenhouse research on American skullcap (Scutellaria lateriflora) and its flavonoid contents under the supervision of Dr. Dennis A. Shannon

Beyond OSU


  • Shiwakoti S., V. D. Zheljazkov, H. T. Gollany, B. Xing, and M. Kleber. 2019. Micronutrient Concentrations in Soil and Wheat Decline by 52 Years of Tillage and Winter Wheat-Pea Rotation . Agronomy. 9: 359. Full text link.
  • Shiwakoti S., V. D. Zheljazkov, H. T. Gollany, M. Kleber, B. Xing. 2019. Effect of tillage on macronutrients in soil and wheat of a long-term dryland wheat-pea rotation. Soil & Tillage Research. 190: 194-201. Pdf.
  • Shiwakoti S., V. D. Zheljazkov, H. T. Gollany, B. Xing, and M. Kleber. 2019. Macronutrients in Soil and Wheat as Affected by a Long-term Tillage and Nitrogen Fertilization in Winter Wheat-Fallow Rotation. Agronomy. 9: 178. Pdf.
  • Semerdjieva, I., S. Shiwakoti, C. Cantrell, V. D. Zheljazkov, T. AStatkie, V. Schlegel, and T. Radoukova. 2019. Hydrodistillation extraction kinetics regression models for essential oil yield and composition in Juniperus virginiana, J. excelsa, and J. sabina. Molecules. 24: 986. Pdf
  • Shiwakoti S., V. D. Zheljazkov, V. Schlegel. 2018. Influence of winter stress and plastic tunnels on yield and quality of spinach, pak choi, radish, and carrot. Emirates Journal of Food and Agriculture. 30: 357-363. Pdf
  • Shiwakoti, S., O. Saleh, S. Poudyal, A. Barka, Y. P. Qian, and V.D. Zheljazkov. 2016.  Yield, composition and antioxidant capacity of the essential oil of sweet basil and holy basil as influenced by distillation methods. Chemistry and Biodiversity. 14 (4) e1600417.  Pdf.
  • Shiwakoti, S., V. D. Zheljazkov, V. Schlegel, and C. L. Cantrell. 2016. Growing spearmint, thyme, oregano, and rosemary in northern Wyoming using plastic tunnels. Industrial Crops and Products. 94: 251-258. Pdf. 
  • Shiwakoti S., D. Shannon, C. W. Wood, N. Joshee, K. Lawrence and A. Rimando. 2016. Nitrogen, phosphorus and potassium effects on biomass yield and flavonoid content of American skullcap (Scutellaria lateriflora). Journal of Plant Nutrition.39:120-1249. Pdf.
  • Shiwakoti S., V. D. Zheljazkov, S. Poudyal, O. Saleh, V. Schlegel. 2016. Method for attaining caraway seed oil fractions with different composition. Chemistry and Biodiversity. 13: 695-699. Pdf.
  • Zheljazkov, V.D., S. Shiwakoti, T. Astatkie, I. Salamon, D. Grulova, S. Mudrencekova, and V. Schlegel. 2015. Yield, composition, and antioxidant capacity of ground cumin seed oil fractions obtained at different time points during the hydrodistillation. HortScience. 50: 1213-1217. Pdf.
  • Shiwakoti, S., H. Y. Sintim, S. Poudyal, J. Buffalo, C.L. Cantrell, T.Astatkie, E. Jeliazkova, L. Ciampa, and V. D. Zheljazkov. 2015. Diurnal effects on Mentha Canadensis oil yields and composition. HortScience. 50: 85-89.Pdf.
  • Zheljazkov, V.D., T. Astatkie, S. Shiwakoti, S. Poudyal, T. Horgan, N. Kovatcheva, A. Dobreva. 2014. Essential oil yield and composition of garden sage as a function of different steam distillation times. HortScience. 49: 785-790. Pdf.
  • Shiwakoti S., D. Shannon, C. W. Wood, N. Joshee, K. Lawrence and A. Rimando. 2013. Harvesting number and timing effects on shoot yield and flavonoid content in organically grown american skullcap (Scutellaria lateriflora). Journal of Herbs, Spices & Medicinal Plants19:248–261. Pdf.


Zheljazkov, V. D., S. Shiwakoti, E. A. Jeliazkova, and T. Astatkie. 2016. Chemical profile and bioactivity of essential oil fractions as a function of distillation time, p. 145-166. In: Jeliazkov (Zheljazkov), V.D. and C.L. Cantrell (eds.). Medicinal & Aromatic Crops: Production, Phytochemistry, & Utilization. American Chemical Society Symposium Series. ACS publications. Washington D.C. U.S.A. Link.

My Publications