UV-B辐射增强下施氮对大麦土壤微生物量碳、氮的影响

通过田间试验，研究了UV-B辐射增强下不同施氮量对大麦土壤微生物量碳、氮的影响。UV-B辐射设对照（CK）和增强（E）2水平，施氮量设高、中、低3水平，分别为30、150和300 kg N/ha。结果表明：与对照相比，无论施氮量高低，UV-B辐射增强对非根际土壤微生物量碳、氮含量有促进作用；除低氮外，UV-B辐射增强对根际土壤微生物量碳、氮含量有抑制作用。在一定UV-B辐射强度下，高施氮量会降低根际土壤微生物量氮和非根际土微生物量碳、氮含量。

Effects of enhanced ultraviolet-B radiation and nitrogen levels on microbial biomass carbon and nitrogen in barley

Field experiment with barley was conducted to investigate the dynamics of soil microbial biomass C and N as affected by enhanced ultraviolet-B radiation and N supply. The experiment was designed with 2 levels of UV-B radiation and 3 levels of N supply, i.e. 30, 150 and 300 kg N ha-1. The results indicated that, compared with control, enhanced UV-B radiation increased microbial biomass C and N in non-rhizospheric soil, regardless of N supply levels; but decreased microbial biomass C and N in rhizospheric soil, except for low N supply level. Irrespective of UV-B radiation, high N supply level depressed microbial biomass N in rhizospheric soil as well as microbial biomass C and N in non-rhizospheric soil.