The Spatial Distribution Of Soil Organic Matter And The Relationship With The Land-use In Gansu Province

Soil organic matter is considered an important indicator to measure one of soil fertility, which is the source of plant nutrients and improve soil structure.physical and chemical properties and enhance the capacity of soil protection and buffer properties of fat with physical activity, can promote the growth and development of crops with a complex role,contribute to the elimination of soil pollution. Soil organic matter is mainly terrestrial carbon storage library, the stability of organic carbon to the greenhouse effect and global changes, such as China due to deforestation, soil erosion caused by persistent, severe loss of soil carbon sinks. Therefore, the study of soil organic matter is an important basic science issues.Based on the surface(0-20cm)of the 81 counties, the determination of soil organic matter .Analysis of soil organic matter of Gansu Province, the space changes and with the climatic factors, land-use changes in the type of trend. Give the following findings:1. Soil organic matter from south to north as the latitude there was a downward trend in Gansu, Soil organic matter in surface and latitude significant negative correlation. soil organic matter is Non-significant change in longitude. Gansu Province, north and south with a flat east-west strip of the terrain, south-west north-eastern low-lying high and complex characteristics of a variety of landforms. Counties in Gansu Province of the average levels of soil organic matter with a clear vertical distribution, with the increase in altitude polar surface soil organic matter significantly increased, y=0.0015x-0.9414,R~2=0.3836,and a correlation coefficient of 0.619 **.2. Climate directly affects the soil hydrothermal condition and the physical, chemical process, the nature and intensity of soil organic matter by the impact of climate change significantly in Gansu. Soil organic matter in 81 counties with the annual average temperature decreased, both were highly significant negative correlation, y=-0.2636x+4.279,R~2=0.1651,a correlation coefficient of -0.406 **. The content of soil organic matter decreased with increasing rainfall trend, y=0.0023x+1.2045,R~2=0.063, a correlation coefficient of 0.251 *.3. Different land use patterns of soil organic matter in Gansu is grassland > forest land > farmland> unused land. Grassland, woodland was significantly higher than that of cultivated land and unused land. This is the type of soil, temperature and humidity, light intensity, vegetation type, microbial activity, such as the relationship between great4. The exception of six eco-regions in the Loess Plateau of East Gansu Hexi Corridor and soil organic matter were Non-significant differences, the other ecological regions of soil organic matter have a significant difference.Gannan plateau significantly higher than the remaining five regions, and 5.2 times of Hexi Corridor,4.9 times of Loess Plateau of Longdong; Qilian Mountains is 4.5 times of Hexi Corridor and the and 4.4 times of the Loess Plateau of Longdong.Ecological region in six different land use types of soil organic matter status: Longnan mountain forest was significantly higher than that of arable land; the Hexi Corridor, Gansu Longdong plateau of the Loess Plateau and soil organic matter was significantly higher than that of arable land, grassland and unused land ; Longxi Loess Plateau of grassland soil organic matter was significantly higher than that of arable land, forest land and unused land, but cultivated land and unused land were Non-significant differences between; Qilian Mountains to the four kinds of land-use types of soil organic matter no significant difference.