Nitrogen partitioning and cycling in barley-soil systems under conventional and zero tillage in central Alberta

Abstract

The objectives of this study were: to assess the effects of urea injection on N partitioning in barley-soil systems under conventional (CT) and zero tillage (ZT); and to measure the dynamics of fertilizer and soil N over the growing season. Twelve microplots were installed in each of CT and ZT plots located on a black Chernozemic soil and were fertilized with 15N urea solution and sown to barley and destructively sampled. The recovery of fertilizer N in the soil-plant system was not different between treatments. Microbial N and non-microbial organic N accounted for >80% of residual 15N in both treatments. The study suggests that more 15N from injected urea was converted to organic N under ZT than CT; thus ZT systems have the potential of conserving N. Tillage practices affect the fate of added N. -from Authors