Evaluating nitrate leaching potential for two different hydrological soil groups using a conservative tracer
This research examined field measurements and the HYDRUS 1-D (version 4.12) model to quantify annual movement of NO3-N through two soils of different HSG groups (B and C) using a Cl tracer and examine leaching losses attributed to the winter months (November 2007 – April 2008). Field and model data confirmed potential leaching losses ~ 72% (Cl mass recovery) over these months. Differences in Cl and nitrate-N mass recovery indicated potential N losses via other processes such as denitrification and/or immobilization. The 200 kg N ha-1 treatment was most indicative; site’s B and C had 1% and 9% losses, respectively. Both sites exhibited ~ 96-99 % loss of soil nitrate-N and Cl of the fall-applied N and Cl by September 2008. Monthly crop sampling demonstrated ~ 1% soil mineral-N remained at harvest (November 2008). These findings further support the effectiveness of applying N in the spring than the fall.