Fate and Form of Nitrogen under Different Soil Redox Status

Abstract

The experiment sets out to investigate the effect of oxidation-reduction on nitrogen formsin soil. The trial was a 3 x 2 factorial experiment laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Treatment consisted of two variables which are poultry manure at three levels (0t/ha, 6t/ha and 8t/ha) and water regime at two levels (field capacity and waterlogged).The combinations resulted into six (6) treatments resulting into three oxidation-reduction potential range [oxidized (>300), moderately reduced (-100 to 300), reduced (<-100)]. Data collected pH, Eh, Total nitrogen, Organic matter,NO3—N and NH4+-N. Data collected were subjected to Analysis of variance (ANOVA) while mean were separated using Tukey Honesty Significant Difference (HSD) Test. Graphs were generated using Microsoft excel. The result showed that nitrogen under oxidize condition is majorly in nitrate form while under reduced condition is ammonia. However, moderately reduced soil had the highest total nitrogen content. This is attributed to the fact that both forms of nitrogen are present in the soil as a result of accumulation of NH4+ and progress of nitrification process. It was concluded that the forms and fate of nitrogen in soil also depends on the oxidation-reduction status of the soil.