Abstract

Little is known about the activity of soil microbes towards the utilization of organic substrates in the rhizosphere of crops during the growing season. Deficiencies in key macro nutrients, Phosphorous (P) and Nitrogen (N), trigger alterations in gene cell structure of both plant and microbes in a spatial-temporal manner. A redox technique in the form of Biolog® EcoPlates was used to measure the utilization patterns of 31 organic substrates by microbes in canola (Brassica napus) rhizosphere under 4 treatments. Discriminant analyses presented 9 substrates that were most significant to fertilizer treatment and 21 most significant to WOS(Week of sampling, or crop growth stage). Factorial analyses determined these substrates are categorized by their chemical nature and crop growth stage.