In order to explore the current status and influencing factors of soil organic matter in Northwest China

this paper used ArcGIS and geostatistics to study the spatial distribution of soil organic matter and its influencing factors in Northwest China. The results showed that:(1) The overall soil organic matter content in the study area is at a relatively low level

with grade 3 and below accounting for 68.94%

the organic matter variation range is 1.10~107.5 g/kg

and the average value is 20.13 g/kg; the organic matter is obtained by semivariance function model analysis. The optimal theoretical model was the spherical model. (2) By drawing the spatial distribution map of soil organic matter in the entire northwestern region

it could be seen that the organic matter content in the eastern part of the study area from Ningxia

northern Shaanxi to southern Gansu and southern Shaanxi shows a gradual increase. The central area of the Tarim Basin was distributed in concentric circles increasing to the boundary. The high-value areas of organic matter were distributed in the eastern part of Qinghai and the Tianshan Mountains in Xinjiang; the low-value areas were distributed in Ningxia

northern Shaanxi

and the Tarim Basin in Xinjiang. Such a distribution trend was somewhat similar to the distribution of large topographical areas in Northwest China. (3) There was a positive correlation between soil organic matter content and altitude and precipitation. (4) There were significant correlations between organic matter and soil types and land use patterns. The content of soil organic matter in grassland and woodland was significantly higher than that of cultivated land and unused land

but there was no significant difference between grassland and woodland. Altitude and precipitation were the main factors affecting organic matter

which can explain 49% of changes in soil organic matter. The results of this study will not only help qualitatively and quantitatively understand the spatial distribution of organic matter in Northwest China

but also provide a reference for soil texture for the construction of ecological agriculture and ecological environment protection in this region.