The use of different species of cover plants and irrigation levels can affect the availability of nitrogen (N) and forms of N in the soil. In this study, total N and its inorganic forms in the soil were evaluated in the experiment with banana cultivation associated with cover plants and irrigation levels. The experiment was conducted in the state of Ceará in the Brazilian semiarid region with the design of randomized blocks and split plot with four replications. In the plots were evaluated four

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... irrigation levels (50, 75, 100 and 125% of evapotranspiration of banana plants), were evaluated in the subplots four cover plants (Pueraria phaseoloides Benth, Calopogonium muconoides Desv., spontaneous vegetation and residue of banana plants) and sub-subplots two soil layers (0-5 cm and 5-10 cm) were evaluated. In general, the result of the leguminous Pueraria phaseloides Benth showed a higher content of total N and its inorganic forms throughout the evaluation period in comparison to the other types of coverage. As for the effects of irrigation levels, it was found that the highest levels led to the lowest content of nitrate (N-NO 3 -), compared to the levels of ammonium (N-NH 4 +). Regarding the depth, was observed higher levels of total N and N-NO 3in the most superficial layer and higher NH 4 + levels in the subsurface layer of the soil. Thus, the use of Pueraria phaseoloides Benth as a cover plant can improve the availability of N for a crop of agronomic interest, mainly in the most superficial layer of soil, with most of this N being in the form of NO 3 -.