Abstract:

Using soil column incubation method, the effect of salt covering (CK, no salt covering; T1; T2; T3 and T4: salt covering with 1, 2, 3 and 4 times amount of salt in soil) on soil respiration was studied with a Li-8100 automated soil CO2 flux system in Balikun Saline Lake. The diurnal variation of soil respiration showed a single peak curve, with the peak value increased with amount of covered salt. The time of peak value showed in 15:00 under T4 treatment, but 17:00 under other treatments. The flux of soil respiration was negative from 0:00 to 6:00. Soil respiration showed a trend that first increase then decrease with incubation time after salt covering. Change of daily average soil respiration rate during incubation time and Q10 value showed an increase trend with amount of covered salt, with daily average soil respiration rate under T4 treatment significantly higher than that under CK treatment. Our study suggested that not only temperature, but also salt covering and its influence on Q10 value should be considered when study saline soil respiration under climate warming condition.

Key words: soil respiration, surface salt covering, Balikun Saline Lake