Nitrogen supplying power of canola versus pea stubble under zero and conventional tillage systems
Flaten, B. and K. Greer. 1998. In Proc. of the Wheat Protein Symposium. Univ. Saskatchewan
Abstract
Plant Root Simulator (PRS™)-probes were used to measure the nutrient supplying power of soil of unfertilized canola and pea stubble under both zero and conventional tillage systems. Nutrient supplying power measuring nitrate was taken over three, two week periods. Ammonium was measured in the first two time periods only. Early in the growing season, soils under canola stubble had 14% higher nitrate supplying power as compared to those under peas stubble. However, later in the season, soils under pea stubble supplied almost twice as much nitrate as canola stubble. Differences in nitrate supplying power between tillage treatments only showed up during mid June, when zero tillage has significantly higher nitrate supplying power than conventional tillage. Nitrate supplying power of canola stubble under zero tillage was significantly higher than under conventional tillage, reflecting greater N immobilization by decomposing canola residue. Conversely, land under pea stubble was not affected by reside incorporation. Pea stubble under the two tillage systems showed no significant differences buy trended towards slightly higher nitrate supplying power under conventional tillage as compared to zero tillage. Wheat yield and protein response are looked at in another report.
