UV-B辐射增强对大麦田土壤呼吸的影响

目的]通过在典型晴天和阴天利用LI-8100对拔节期大麦田土壤呼吸速率的测定,研究UV-B辐射增强20%对土壤呼吸速率的影响。方法]采用田间试验,人工增加和控制UV-B辐射的强度。结果]UV-B辐射增强显著抑制大麦田的土壤呼吸。晴天时正常大麦田（B）的土壤平均呼吸速率比UV-B辐射增强20%处理的麦田（BU）高1.02μmol/（m2.s）,在阴天无外源UV-B辐射强迫的情况下,B处理的土壤平均呼吸速率则比BU处理低0.71μmol/（m2.s）。晴天UV-B辐射增强导致大麦田土壤呼吸的Q10值减小,而阴天无UV-B辐射胁迫时土壤呼吸的Q10值增加,导致了土壤呼吸速率的不同变化。结论]UV-B辐射增强会显著抑制大麦田的土壤呼吸速率,从而影响作物产量的增加。

Effects of Enhanced UV-B Radiation on Soil Respiration of Barley Field

Objective] The aim was to study the effects of enhanced UV-B radiation on field soil respiration in clear day and cloudy day in jointing stage of barley,LI-8100 was used to measure soil respiration under 20% UV-B radiation increase.Method] The research was made by using field experiment to increase and control intensity of UV-B radiation.Result] The results showed that:enhancing UV-B radiation obviously inhibited soil respiration rate of barley field.In clear day,average soil respiration rate of normal barley field(B)is 1.02 μmol/(m2·s)higher than enhanced 20% UV-B radiation barley field(BU).In cloudy day under non-UV-B radiation force situation,average soil respiratory rate of B treatment is 0.71 μmol/(m2·s)less than BU treatment.Enhancing UV-B radiation caused the Q10 value of barley field soil respiration to reduce in clear day,but in cloudy day under non-UV-B radiation force situation,Q10 value increased,that is the reason for different change of the soil respiration rate.Conclusion] Supplemental UV-B radiation will inhibit the soil respiration rate on barley filed obviously and affect the increase in crop yields.