Tillage Effects On Water Flow, Soil Mineral Nitrogen and Corn Yield In Tile Drained Fields Amended with N-Viro SoilŪ.

Tillage is an important agricultural practice affecting soil water flow, soil nutrient dynamics and crop yield.  A 3-year (2008-2010) soybean-corn-corn experiment was conducted to study water flow, seasonal soil mineral nitrogen dynamics and corn (Zea mays L.) yield in a long-term conventional tillage (CT) versus zero tillage (ZT) field site in Nova Scotia, Canada.  Alkaline stabilized biosolids, N-Viro Soil^®, at a rate of 14 Mg ha^-1 were applied in the spring of 2009 and again in 2010 as both an N source and lime substitute.  The volume of surface runoff and subsurface drainage was monitored by Campbell Scientific CR10X Datalogger.  Soil samples were collected multiple times during crop growing seasons to determine soil moisture, soil inorganic N  and soil pH.  During the corn growing season from May to Sep. 2009, surface runoff was comparable between the CT treatment (22 mm ha^-1) and ZT treatment (24 mm ha^-1); however, subsurface drainage was 22% lower in the CT (47 mm ha^-1) treatment than in the ZT (60 mm ha^-1) treatment.  The annual water flow, the sum of surface runoff and subsurface drainage, was 110 mm yr^-1 ha^-1 lower in the CT treatment than in the ZT treatment.  During most sampling periods, tillage treatment had no significant effects on soil mineral N or soil pH, but the CT decreased soil moisture content when compared with the ZT treatment.  In both years, corn grain yield was relatively low and averaged 4.9 t ha^-1 in 2009 and 3.1 t ha^-1 in 2010. Corn yield in the ZT treatment was 9% higher in 2009 and 7% higher in 2010 relative to the CT treatment.