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The dynamic nature of N cycling dictates that soil N capital useful for supplying N for plant growth must be equated with short‐ to medium‐term, rolling capital (the monthly or annual salary), rather than long‐term reserves (gold in the bank). Thus building of soil N capital necessitates a focus on the capacity of soils to store organic matter (the principal reserve of N in the soil) and on management strategies to replenish N reserves. For a given climate, the capacity of a soil to store organic matter is directly related to its texture through both direct effects of clays adhering to organic matter and indirect effects on soil aggregation, which render the organic matter protected from decomposition. Some African soils can contain up to 300 to 400 kg N ha⁻¹ in free mineral form within the top 2 m of soil, which represents a form of vulnerable capital susceptible to leaching. Large amounts of organic inputs are required to build up …