Self-developed soil conditioner composites containing fermented chicken manure as a raw material alongside bentonite and super-absorbent polymer in different doses and combinations were tested in a 112 day long soil incubation experiment. This study aimed to determine their effects on soil N mineralization, and the changes in the amount of soil mineralized nitrogen forms, cumulative mineralized nitrogen (Nmin), min ), and C/N ratio in a sandy soil (Lamellic Arenosol) at two different soil water holding capacity (SWHC) levels and soil layers. Potentially mineralized nitrogen (PMN), net mineralization rates (NMR), and nitrification rates (NNR) were also calculated to study the effectiveness of treatments. Soil NH4-N 4-N decreased by 50-70% while NO3-N 3-N increased by 150-200% in the treated soil, so the NO3-N 3-N and NH4-N 4-N ratio changed from 1/3 to 2/1 during the incubation. N min gradually increased and was described by a linear tendency (R >= 0.99) for both soil layers and SWHC levels. Composite treatments increased significantly the PMN, and NMR values by 2-4 times and NNR values by 40-240% compared to the control. Applied composites enhanced the mineralized proportion of total nitrogen content by 2-6%. It was found that the composites were more effective at lower SWHC level and in their application layer than chicken manure alone. Overall, the developed organic-based composites are able to cope with changing soil conditions, which can help mitigate the negative effects of climatic anomalies, especially in arid areas with limited water resources by improving soil nutrient supply, thus contributing to sustainable nutrient management.