不同肥料对连作烟草根际土壤微生物及酶活性的影响

烟草连作障碍是制约烟草产量与品质的关键因素。以连作12年的烟草土壤为对象,通过施用不同肥料, 研究了不同肥料对连作烟草产量、根际土壤微生物量、土壤酶活性的影响。结果表明：不同施肥处理对连作烟草产量及土壤微生物及酶活性的影响存在一定差异,施用农家肥有利于提高连作烟草产量。土壤微生物量分析结果显示,不同施肥处理后烟草根际土壤微生物量碳、氮及微生物呼吸强度依次为：农家肥>有机肥>氮肥>复合肥。与土壤营养循环相关酶活性的分析结果表明,不同施肥处理后烟草根际土壤中性磷酸酶、碱性磷酸酶、脲酶、蔗糖酶活性以有机肥处理后活性最大,而酸性磷酸酶则以农家肥处理后活性最高。与土壤生物抗逆性相关的多酚氧化酶、过氧化物酶、过氧化氢酶、脱氢酶活性分析的结果显示,不同施肥处理后烟草根际土壤抗性相关酶活性大小依次为：农家肥>有机肥>氮肥>复合肥。

Comparative Studies on Comprehensive Economic Cost of Wood-based Biomass-fired and Coal-fired Cogeneration Plant

This paper established a comprehensive economic cost model involving the environmental cost.The economic and environmental performance of biomass-fired and coal-fired cogeneration plant was compared using this model.The reasons which make the biomass energy less competitive in the market,and the development potential of biomass-fired and coal-fired were analized.It is concluded that the economic cost of biomass energy is still too high,due to the expensive material and imported equipment,which make the biomass energy less competitive in the market,while the environmental benefit is still remarkable.Comprehensive economic cost of biomass was superior to coal-fired cogeneration.The biomass combustion heating is more cost and environmental effective than biomass combustion generation at the present.With the decrease of fossil fuel reserve,investments will spontaneous pour into technology development of biomass energy driven by the market,in order to cut down the cost;and the policy support which including raw material supply,technology research and development and market cultivation will accelerate the technology progress of biomass energy.