UV-B辐射增强下施氮对大麦根际土壤酶活性的影响.doc

  UV-B 辐射增强下施氮对大麦根际土壤酶活 性的影响# 娄运生1，程焕友1，韩艳2* 5 10 15 （1. 南京信息工程大学应用气象学院，南京 210044； 2. 河南大学环境与规划学院，开封 475000） 摘要：大田条件下，研究了 UV-B 辐射增强及不同施氮水平下，大麦不同生育期根际和非根 际土壤纤维素酶、碱性磷酸酶和脲酶活性的动态变化。UV-B 辐射设 2 水平，即对照（CK， 自然光，12.0 kJ m -2 d -1），增强 20% (Elevated, 14.4 kJ m -2 d -1)。施氮量设 3 水平，即 30、 150 和 300 kg hm-2。结果表明：与对照相比，UV-B 辐射增强对大麦根际土壤纤维素酶、碱 性磷酸酶和脲酶活性的影响，因生育期和施氮量而异。中高氮下，UV-B 辐射增强可降低根 际土壤纤维素酶、碱性磷酸酶和脲酶活性，而低氮下 UV-B 辐射增强则提高相应酶活性，但 UV-B 处理间差异大多不显著。在 UV-B 辐射增强下，随施氮量增加，根际土壤纤维素酶活 性下降，而碱性磷酸酶和脲酶活性呈先降后升趋势，但施氮量处理间差异大多不显著。根际 土壤酶活性与非根际土壤相比，既有升高也有下降。研究认为，UV-B 辐射增强尚不足以对 大麦根际土壤纤维素酶、碱性磷酸酶和脲酶酶活性产生显著影响，这可能与设定的 UV-B 辐 射强度、试验方法及采样方法有关。 关键词：应用气象学；UV-B 辐射；大麦；根际土；土壤酶活性 中图分类号：请查阅《中国图书馆分类法》 20 Effect of enhanced UV-B radiation and N levels on enzymatic activities in barley rhizosphere soil LOU Yunsheng1, CHENG Huanyou1, HAN Yan2 (1. College of Applied Meteorology, Nanjing University of Information Science and 25 30 35 40 45 Technology,Nanjing China 210044； 2. College of Environment and Plan, Henan University,Kaifeng China 475000 ) Abstract: The stratospheric ozone layer formed a protective atmospheric filter against biologically harmful solar ultraviolet (UV) radiation. Anthropogenic emissions of chlorofluorocarbons and nitrogen oxides resulted in depletion of ozone layer. Consequently, enhanced levels of UV-B radiation (280~320nm) had been detected in the world. Enhanced UV-B radiation had been confirmed to negatively affect plant growth and development in higher plants. Barley is the forth most important worldwide cereal crop, after wheat, maize and rice, but very few studies have been conducted concerning its response to enhanced UV-B radiation. Field experiment with barley was conducted to investigate the dynamics of enzyme activities as affected by elevated ultraviolet-B radiation and N supply. The experiment was designed with two UV-B radiation levels, i.e. ambient (A, control, 12.0 kJ m -2 d -1) and elevated by 20% (E, 14.4 kJ m -2 d -1), 3 levels of N supply, i.e. 30, 150 and 300 kg N hm-2and