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The fate of the added N on a sandy loam soil was determined in an improved fallow - maize sequence field experiment in Zimbabwe. Pre-season mineral N was determined in 20 cm sections to 120 cm depth by soil auguring in seven land use systems. Thereafter, sequential soil auguring was done at two-week intervals in plots that previously had 2-year fallows of Acacia angustissima, Sesbania sesban and unfertilized maize to determine mineral N dynamics. Using the static chamber technique, N₂O fluxes were also determined in the same plots. Pre-season NH₄-N concentrations were >12 kg N ha⁻¹ in the 0–20 cm layer for treatments that had a pronounced litter layer. NO₃-N concentrations below 60 cm depth were <3 kg N ha⁻¹ layer⁻¹ for Sesban, Acacia, Cajanus cajan and natural woodland compared with >10 kg N ha⁻¹ layer⁻¹ in the control plots where maize had been cultivated each year. There …