土壤反硝化是流域土壤氮损失的重要途径之一。利用乙炔抑制培养法对五川流域内表层土壤的反硝化进行测定,研究发现,闽南农业小流域土壤具有较强的反硝化作用强度,在种植季节土壤平均反硝化作用强度为N 0.1 kg/(hm2.d),最高达到N 0.6 kg/(hm2.d),其中蔬菜地反硝化作用强于其他土地利用类型。反硝化作用同土壤的含水量、温度以及NO3-含量都存在有正相关关系,温度是流域土壤反硝化作用的最主要影响因子。五川流域土壤经由反硝化作用氮损失量占流域施肥量的16%,稍高于国内其他地区。Denitrification from soils is the main pathway of gaseous loss for nitrogen in the catchments.We measured the denitrification rate from the top-soil in Wuchuan catchment by using the acetylene inhibition technique.The result of this experiment indicated that denitrification of the soil had the temporal and spatial variance.The rate of denitrification that occurred in uplands of the catchment was higher than any other places,and denitrification was enhanced when there were many rains and when the soil temperature was high.The flux of denitrification was mostly related with fertilization,soil moisture and air temperature.Air temperature was top-dressed affected denitrification significantly.The gaseous N loss rate through denitrification represent about 16% of the fertilizer applied in the catchment scale.国家自然科学基金(40301045
