The Effects Of Experimental Warming And Nitrogen Addition On Soil In Desert Steppe

To study the effect of warming, nitrogen fertilizer and the compound effect of the warming and the nitrogen fertilizer on the communities of the Breviflora+ Artemisia frigida + Cleistogenes songorica desert steppe in Inner Mongolia and the production ability of the plain, the sample plot was heat by the MSR-2420 infrared radiators while being processed by the nitrogen fertilizer. In a simulated global warming condition, we research the effect of warming and N addition on soil and explore the desert grassland ecosystems to global climate change response mechanism for our Global Change and Terrestrial Ecosystems provide long-term research platform. The result of paper showed:1)During the experiment (form on June 24, 2006 to on October 11, 2008), comparison with CK (0cm,7.5cm,15cm,30cm and 50cm), the temperature of soil increased 1.42℃,0.98℃,0.94℃,0.81℃and 0.71℃in warming plot, respectively. The variability of soil temperature was larger in upper than in lower, especially in 2008, the signature (P<0.05) was observed in the same treatment layer both between warming treatment and CK.2)Warming and N addition have a certain impact on the soil of desert steppe. Although elevated soil temperature has caused increased of soil moisture (0-30cm), no signature variable was observed (P>0.05).3)Warming improved the content of soil organic matter, total nitrogen, total phosphorus, nitrogen speed, speed P, Speed K, ammonium nitrogen. Among of them, warming of the organic matter, fertilizer, rate of phosphorus, ammonium nitrogen fertilizer was higher than warming plus N supply. In 2007, soil organic matter, phosphorus-speed in 2007 with 10 ~ 20cm is significantly (P<0.05) in warming plots higher than in warming plus N addition plots, N addition plots and CK plots.The content of total phosphorus, total nitrogen, speed nitrogen, speed potassium was higher in warming plus N addition plots than warming plots. Compared with warming, N addition and CK, the content of total nitrogen with 10-20cm was higher (P<0.05) in warming plus N addition plots. Both two years (in 2007 and 2008), the content of speed nitrogen and speed potassium with 0-30cm was higher (P<0.05) in warming plus N addition than other treatments (warming, N addition and CK). 4)Effectively increase content of nitrate nitrogen in N addition. The content of soil nitrate nitrogen was higher in warming plus nitrogen supply plots than in warming plot. Compared with other treatments (warming, N addition and CK), warming and N addition was significantly increased (P<0.05) the content of nitrate nitrogen with 0-10cm in both two years.5)With the deepening of soil, the content of soil organic matter, total nitrogen, total phosphorus, and speed nitrogen, speed P and Speed K was decreased in warming and N addition plots, whereas the content of soil organic matter, total nitrogen and total phosphorus were higher (P<0.05) in 0-10cm than in 10-20cm and 20-30cm.6)Through analyzing parameters the correlation between simulated experiment (include warming and N addition) and soil chemical properties, we obtained that among of soil organic matter, total nitrogen, total phosphorus, nitrogen and ammonium-speed have a positive correlation of each other.7)Warming and N addition increased soil respiration but no signature (P>0.05) was found. The extent of the impact on warming and N addition to soil respiration was closely related to soil surface temperature, soil temperature in 7.5cm, and water content with 0-10cm (P<0.01).