Corn utilization of ammoniacal nitrogen from pig slurry in no-tillage and reduced tillage

The objective of this work was to evaluate corn (Zea mays) utilization of ammoniacal N from pig slurry (PS). A field experiment was carried out in a typic Hapludalf. The treatments consisted of the application or not of PS on oat straw, in no-tillage and reduced tillage planting systems. In order to quantify the destination of applied ammoniacal N from the PS, the ammoniacal fraction was enriched with ((NH4)-N-15)(2)SO4. The utilization of ammoniacal N from pig slurry by corn crop was of 15.3% and did not differ between no-tillage and reduced tillage soil systems. At corn physiological maturity, the amount of N-15 recovered from the soil, at 120-cm depth, and from the plant (grain+shoot+roots) was 49.6% of the N-15 applied with pig slurry. The organic N fractions from pig slurry and from soil organic matter were the main sources of N for corn.