College of Agriculture and Bioresources

Research Area(s)

  • Nitrogen fixing plants in cropping systems
  • Legumes
  • Selection of rhizobial strains for legume species

Brief Biography

Diane is a Saskatchewan Ministry of Agriculture co-chair of the Strategic Research Program (SRP) in Soil Biological Processes.  The overall focus of the program is to develop innovative solutions to the problems facing today’s producers—focusing on biological aspects of the soil/water/plant continuum as they relate to nutrient cycling and the efficient use of nutrients by plants.


Soil Science

Research Interests

My research focuses on optimizing the benefits of biological nitrogen fixation in agroecosystems, examining the role of nitrogen fixing plants (trees and shrubs, perennial legumes and annual pulse crops) in agricultural landscapes.  We use stable isotope labeling (13C and 15N) to track the fate of nitrogen and carbon residues and rhizodeposits into subsequent crops in a rotation and into soil organic matter fractions.  A second line of research examines microbial inoculant strain selection and carrier development.

Areas of specialization

  • Nitrogen movement, turnover, availability and efficiency of use by crops in rotation
  • stable isotopes (13C and 15N)
  • nitrogen fixation
  • selection of rhizobial strains for legume species new to Saskatchewan agriculture
  • carrier development for rhizobia


  • Ph.D., University of Saskatchewan
  • M.Sc., University of Saskatchewan
  • B.Sc., University of Calgary

Selected Publications

J.D. Knight, A.J. Cessna, D. Ngombe and T.M. Wolfe.  2016.  Mineralisation and degradation of 2,4-dichlorophenoxyacetic acid dimethylamine salt in a biobed matrix and in topsoil. Pesticide Management Science.  Accepted for publication, 28 January 2016. [AAFC]

J.D. Knight.  2015.  Delayed inoculation of alfalfa with Sinorhizobium meliloti and Penicillium bilaiae.  Canadian Journal of Plant Science 95: 205-211. [SMA]

N. Bazghaleh, C. Hamel, Y. Gan, B. Tar’an and J.D. Knight.  2015. Genotype-specific variation in the structure of root fungal communities is related to chickpea plant productivity.  Applied and Environmental Microbiology 81: 2368-2377. [AAFC]

G. Issah, A.A. Kimaro, J. Kort and J. D. Knight.  2015.  Nitrogen transfer to forage crops from a caragana shelterbelt.  Forests 6: 1922-1932. [AAFC]

M.M. Arcand, J.D. Knight and R.E. Farrell. 2014. Differentiating between the supply of N to wheat from above and belowground residues of preceding crops of pea and canola. Biology and Fertility of Soils 50: 563-570.

P. Leinweber, J. Kruse, C. Baum, M.M. Arcand, J.D. Knight, R. Farrell, K. Eckhardt, K. Kiersch, and G. Jandl. 2013. Advances in Understanding Organic Nitrogen Chemistry in Soils Using State-of-the-art Analytical Techniques, In: D. Sparks (Ed.), Advances in Agronomy 119: 83-151.