Ammonia volatilization and nitrogen runoff losses from moso bamboo forests after different fertilization practices

摘要

Moso bamboo (Phyllostachys edulis (Carriere) J. Houz.) is a major giant bamboo species. Unreasonable fertilization and nitrogen (N) loss is a serious problem. A field experiment was conducted to determine the effects of application methods (furrow and hole) and depths (0-20 and 20-40 cm) on ammonia (NH3) volatilization and N runoff losses from June to December, 2015. Ammonia volatilization was detected as a single peak curve after fertilization. Three weeks later, fluxes of all fertilization treatments were similar to those of the control and remained stable. After the experiment, the cumulative NH3 volatilization was 17.2-21.4 kg.ha(-1). Approximately 90% of NH3 volatilization occurred within the first two weeks. The NH4+-N loss was higher than the NO3--N loss, and the total runoff losses were relatively low. For the same application method, with the increase of application depth, the NH3 volatilization and N runoff losses reduced; for the same application depth, the NH3 volatilization and N runoff losses after furrow application were lower than those after hole application. Therefore, the deep and furrow application methods were effective in reducing N loss through NH3 volatilization and runoff. In the present study, furrow application at a 20-40 cm depth has been appropriate for field practice.