Abstract: An analysis and comparison between a cultivated grassland and a plot of traditional farmland of China's southern hilly regions on energy and nutrient-material use efficiency shows that the output of energy and nitrogen of the cultivated grassland ecosystem,in the first year of planting forages,was higher than that of the traditional farmland ecosystem.Forages are more efficient in radiation energy use than cereal crops,and could more efficiently use the auxiliary energy,nitrogen and phosphorus as well.The profit of planting forages resembled that of planting peanut and rape.The effects of the cultivated grassland in the second year were still better than those of the first year,witnessed by the higher output of energy,of nitrogen and phosphorus,the energy and material use efficiency,and the ultimate economic benefit compared to those of the farmland ecosystem.

Key words: Cultivated grassland, Farmland, Ecosystem, Energy use efficiency, Material use efficiency, Economic benefit

摘要： 分析比较我国南方丘陵地区人工草地和旱作农田能量和养分物质的利用效率。结果表明:在建植第1年,人工草地的能量和氮的输出量大于旱作农田;牧草可有效提高光能利用率,对辅助能和氮、磷的利用效率也显著高于后者;二者经济效益相近;种草第2年的效益比第1年更好,其能量物质输出量、利用率和经济效益都显著高于旱作农田。

关键词: 人工草地, 农田, 生态系统, 能量利用率, 物质利用率, 经济效益