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Aggregation and stabilization of soil organic C (SOC) and N are highly dependent on soil texture and addition of organic resources (ORs). While OR quality may influence SOC and N stabilization within aggregates, the simultaneous addition of N-fertilizers may enhance OR decomposition resulting in loss of SOC. A mesocosm study was conducted on a clayey soil at Embu and a sandy soil at Machanga in central Kenya to determine the influence of soil texture, OR quality and N-fertilizer on aggregation, SOC and N. Tithonia diversifolia (high quality), Calliandra calothyrsus (medium quality) and Zea mays (maize; low quality) residues, natural abundance or labeled with ¹⁵N, were applied to soil at an equivalent rate of 4MgCha⁻¹ compared to no input control. Each treatment was fertilized with 120kg ¹⁴N or ¹⁵Nha⁻¹ as (NH₂)₂CO, or not fertilized. Soil samples were collected at installation of the mesocosms (start …