| Summary: | The mineralization of soil organic nitrogen (N) is the key process in the cycling of N in terrestrial ecosystems. Land-use change to bamboo (<i>Phyllostachys praecox</i>) cultivation that later entails organic material mulching combined with chemical fertilizer application will inevitably influence soil N mineralization (N<sub>min</sub>) and availability dynamics. However, the soil N<sub>min</sub> rates associated with various N fractions of <i>P. praecox</i> in response to land-use change and mulching are not well understood. The present study aimed to understand the effects of land-use change to <i>P</i><i>. praecox</i> bamboo cultivation and organic material mulching on soil N<sub>min</sub> and availability. Soil properties and organic N fractions were measured in a <i>P. praecox</i> field planted on former paddy fields, a mulched <i>P. praecox</i> field, and a rice (<i>Oryza sativa</i> L.) field. Soil N<sub>min</sub> was determined using a batch incubation method, with mathematical models used to predict soil N<sub>min</sub> kinetics and potential. The conversion from a paddy field to <i>P. praecox</i> plantation decreased the soil pH, soil total N, and soil organic matter (SOM) content significantly (<i>p</i> < 0.05); the mulching method induced further soil acidification. The mulching treatment significantly augmented the SOM content by 7.08% compared with the no-mulching treatment (<i>p</i> < 0.05), but it decreased soil hydrolyzable N and increased the nonhydrolyzable N (NHN) content. Both the N<sub>min</sub> rate and cumulative mineralized N were lowest in the mulched bamboo field. The kinetics of N<sub>min</sub> was best described by the ‘two-pool model’ and ‘special model’. The Pearson’s correlation analysis and the Mantel test suggested soil pH was the dominant factor controlling the soil cumulative mineralized N and mineralization potential in the bamboo fields. These findings could help us better understand the N cycling and N availability under mulching conditions for shifts in land use, and provide a scientific basis for the sustainable management of bamboo plantations.
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