Study on spatial and temporal variability for the soil organic of cotton fields in oasis of Xinjiang

The paper studies the temporal-spatial variability and the temporalstability of soil organic matter content in 1997, 2002,2007 through statistical methods to provide theoretical basis for the cotton soil fertility and management in the study area. Oasis cotton area in farmland of the 148th Regimental Farm of the 8th Agricultural Division Xinjiang Production and Construction Corps is the study area. The results show that there is little difference on the coefficient of variation about the soil organic matter during this three periods. The range is 16%~20%, a moderate intensity on variation. These spatial correlations become increasingly weaker over the time,and the variation of the distribution pattern of soil organic matter content display generally increasing trend; the average coefficient of organic matter is 17.22% and the stable region of organic matter account of 24.14% of the total region and mainly distributed in the central part of study area,while the variable region account of 23.44% and distributed mainly in the northeastern part and the western margin of study area. This spatial distribution of the non-uniform over time is probably caused by the development of work about soil testing and fertilizer recommendation, the continuous improvement of tillage measures and the distribution of soil in study area in recent years.