摘要：Nitrification has the potential to decrease the efficiency of nitrogen utilization by plants. The use of nitrifying inhibitory chemicals proved to be effective in controlling nitrification, but also affects beneficial soil microbes. Another attempt to inhibit the more environmentally-friendly nitrification is to use plants that have allelochemical nitrification inhibiting compounds such as the grasses of Brachiaria . The aim of this research is to know the effectivity of B.mutica, B.decumbens , and B.humidicola as inhibitors of nitrification rate in soil. The experiment was carried out by pot experimental method based on nondestructive sampling and Complete Randomized Design, consisting of Brachiaria plant types and various doses of N fertilizer, 100 kg/ha, 150 kg/ha, 200 kg/ha. The results of this study show that 1) B.mutica, B.decumbens, and B.humidicola , highly significant to the soil potential nitrification, but the treatment of various doses of N fertilizer is not significant to the soil potential nitrification. 2) the highest soil potential nitrification in B.mutica rhizosphere was 5.160 mg NO2-/g of soil/5h, while the lowest soil potential nitrification in the rhizosphere of B.humidicola plant was 0.414 mg NO2-/g/5h. 3) From the four treatment of Brachiaria plants can be concluded B.humidicola plant more effective in inhibition of nitrification.
