Soil Health Under No-till Termination of Green Manure in an Organic Grain Rotation.

While there has been an increase in agronomic research focused on no-till termination of green manures (GMr) in organic agriculture as it affects weed control and the following cash crop, the impact on soil health has received little attention. The benefits to soil in no-till conventional agriculture are well known, but no-till GMr management is unique because it leaves a substantial mulch layer on the soil surface. A four-year organic grain rotation (full season hairy vetch – wheat – fall rye – soybean) was established in Truro, NS in 2013. Three levels of GMr termination intensity are being employed; fall tillage (tilled in the fall and spring), spring tillage (rolled in fall and tilled in spring), and no-till using a crop-roller to terminate the hairy vetch. Soil was sampled from two depths (0-5cm and 5-15cm) four times throughout each phase of the rotation in 2013, 2014, and 2015. Data from the green manure, wheat, and the spring of the fall rye phase will be presented. Data describing the impact of GMr tillage intensity on constituents of soil health (particulate organic matter, microbial biomass, and mineral nitrogen) along with wheat nitrogen uptake and yield will be presented.