Effect Of Fertilization On Soil Respiration Rate And Greenhouse Gases Flux In The Desert Steppe

In breviflora desert grassland,with the LI-8100 carbon flux measuring instrument and black box method,To study soil respiration rate of the seasonal and interannual variation,and the changes of greenhouse gas emissions in seasonal,and the relationship between the impact factors in the different fertilization levels. Results are as follows:1. The soil respiration rate(1) The soil respiration rate increased under the nitrogen application, Characteristic performance for N10> CK> N5> N2.5;N, P, NP cells, NP Fertilizer significantly increase soil respiration rate, their relationship is that NP>P>CK>N10.(2) With the temperature increases, The soil respiration rate achieved a peak in middle of July and August, The rule of variation of soil respiration rate has’t compared changed with no fertilization village, fertilization has not changed the variation of soil respiration rate.(3) The soil respiration rate have a significantly relationship with soil temperature in 5 cm and 0～10 cm,The main affecting soil respiration are soil temperature and soil moisture in desert steppe.2. Ecosystems greenhouse gas flux(1) In three different nitrogen gradient in the district,CH4 absorb flux relationship is CK>N2.5>N10>N5,CO2 emission flux relationship is N5>CK>N10>N2.5,N2O emission flux relationship is CK>N5>N2.5>N10; N, P, NP within the district, CH4 absorb flux relationship is P>CK>NP>N10,CO2 emission flux relationship is NP>P >CK>N10,N2O emission flux relationship is CK>NP>P>N10.(2) Compared with the fertilization district, fertilization does not change the rule of the greenhouse gas emission flux in the whole growing season;(3) Greenhouse gas flux have a significantly correlation the soil of 5 cm ground temperature and soil water content. The main affecting greenhouse gases flux are soil temperature and soil moisture in desert steppe.