Soil Nitrogen Cycling as Influenced by Cover Crops in Saskatchewan

Abstract

This research aims to study the viability of growing cover crops in a field crop rotation in Saskatchewan, and the influence of cover crops on soil N availability, cash crop N use, and its potential for reducing N2O emissions. The experiment was initiated in 2018 on sandy loam soil of a Dark Brown Chernozem of the Asquith association, and comprises a 4-year rotation sequence of wheat-canola-potato-pea grown with shoulder-season cover crops (red clover, berseem/oat, rye and tillage radish, respectively) and without cover crops. A short rotation (wheat-canola) and a perennial alfalfa are included as comparison treatments. The plots are arranged in a randomized complete block design with four replicates. Crop yield and biomass measurements are collected, as well as cover crop measurements (plant counts, heights, ground cover, aboveground biomass); samples are analyzed for %N to determine crop performance and N use. Soil inorganic N dynamics are monitored during fall to determine soil N availability and supply. Preliminary results show cover crops did not have any impact on crop yields, but certain cover crops might influence soil N availability in the fall. However, this study is still in its early stage and will continue in order to obtain substantial evidence.