Soil nitrification as affected by Brachiarias

摘要

The nitrification process in soil may result in substantial losses of applied nitrogen through nitrate leaching and N20 emission to the atmosphere. Nitrification control could be a key strategy in improving nitrogen recovery and agronomic N-use efficiency. This study aimed to evaluate the ability of species of Brachiaria in inhibiting nitrification process in the soil. The treatments consisted of growing three pasture species (Brachiaria brizantha, Brachiaria ruziziensis and Brachiaria decumbens) fertilized with doses of nitrogen (0,100, 200 and 300 mg/pot) plus a control (without plants). The experiment was carried out in a greenhouse in pots containing 10/dm~3 of soil. In the absence of the brachiarias, soil NO_3~- increased with N rates. B. ruziziensis, when grown with 60 kg/ha of N, resulted in the lower soil nitrate concentration (an evidence of nitrification inhibition), but B. decumbens and B. brizantha had no effect on the nitrification process.