Effects of various fertilization depths on ammonia volatilization in Moso bamboo (Phyllostachys edulis) forests

The objective of this study was to investigate the effects of various fertilization depths on NH3 volatilization loss in Moso bamboo forests in the Huanshan county, Anhui province, China. A complete randomized block design with five treatments was used, including 0 (T0); 10 (T10); 20 (T20) and 30 (T30) cm application depths and no fertilizer treatment (control). Results showed that NH3 volatilization was detected in a single peak curve after fertilization, peaking at the third day for T0 and T10 treatments, and the sixth day for T20 and T30 treatments, respectively. Twelve days later, the fluxes declined to a low level similar to the control. The mean NH3 volatilization flux decreased with the increase of fertilization depth, ranged from 0.71 kg/ha/day for T30 treatment to 1.68 kg/ha/day for T0 treatment. More than 80% of total NH3 volatilization occurred within the first eight days. After the experiment, the cumulative NH3 volatilization of T0 treatment was 26.8 kg/ha, accounting for 20.8% of the total nitrogen (N) application. Compared with the surface application, deep application of N fertilizer was effective in reducing N loss through NH3 volatilization. T20 treatment is recommended in terms of increasing N absorption, diminishing N leaching loss and labor cost.