Greenhouse Pot Trials to Determine the Efficacy of Black Urea Compared to Other Nitrogen Sources

Abstract

Two separate pot trials were conducted at the research farm of the University of Pretoria to establish the efficacy of Black Urea as compared to normal urea and limestone ammonium nitrate as sources of nitrogen for maize (corn) fertilization. The aim was two‐fold: first to compare it as a banded nitrogen source, and second to compare it as a source of topdressed nitrogen at planting. In the first trial, the pots were not leached to establish the possible salt effects in the fertilizer band. In the second trial, the pots were leached to simulate normal field conditions. In both trials, Black Urea proved superior to normal urea.