Rajan Ghimire

Rajan Ghimire
  • Post-Doctoral Researcher
  • Oregon State Univ (CBARC)
  • Crop and Soil Sciences


Stephen Machado

Research Focus: 

Soil organic matter dynamics in dryland cropping systems

Research Abstract: 

I am a soil science student interested on soil organic matter, nutrients, and microbial dynamics in disturbed systems. My postdoctoral research focuses on soil organic carbon (SOC) and nitrogen (N) dynamics under diverse management practices to address existing and emerging challenges in sustainable crop production. Loss of SOC and N from agroecosystems is a major challenge in sustainable crop production in Pacific Northwest (PNW). Climate change and variability has posed additional challenges on agronomic, economic, and ecological efficiency of existing management practices. I am evaluating long-term trend of SOC, N, and crop yield, and monitors seasonal and inter-annual dynamics of labile (less than a year turnover time) SOC and N pools in the existing long-term experiments as well as in recently established experiments. Organic residue addition, including legume-crops in rotation, and minimum soil disturbance increases SOC accrual and improves sustainability of winter wheat based production systems in this dry region. Pendleton Long-term Experiments provided me a great platform to understand impact of historic changes in management practices, technologies, and production environment to shape the present day agriculture, and helped me to postulate the future trends of dryland farming in PNW.


I grew up in a farm family in mountains of Nepal and received my undergraduate and graduate (M.Sc.) education from Tribhuvan University, Nepal. I worked at Tribhuvan University Institute of Agriculture and Animal Sciences for three years (2006-2009) as a Lecturer of Soil Science. I received my Ph.D. in soils science from University of Wyoming in spring 2013and continued as a Postdoctoral Research Associate during summer and fall 2013. I taught graduate/undergraduate split level courses, soil microbiology and soil fertility, and a special topic (sustainable mountain agriculture) on agroecology capstone course, at University of Wyoming, USA, and several soil science courses at Tribhuvan University, Nepal. My current research as a Postdoctoral Scholar at OSU-CBARC focuses on seasonal and inter-annual dynamics of soil organic carbon (SOC) and nitrogen (N), and their relationship with crop production in the existing long-term experiments and recently established experiments. I am very excited to be part of REACCH project and to understand how alternative management practices and cropping systems influence crop production in PNW and how agricultural systems respond to climate change and variability in this region.

Publications and Presentations: 

Ghimire, R., Machado, S., Rhinhart, K. 2014. Long-term crop residue and nitrogen management effects on soil profile carbon and nitrogen in wheat-fallow systems. Agronomy Journal. 107(6): 2230-2240.
Ghimire, R., Machado, S. Long-Term Trend of Soil Organic Carbon Influenced By Crop Residue and Nitrogen Management Practices. ASA-CSSA-SSSA Annual Meeting, Nov. 3, 2014, Long Beach, CA (oral).