Soil Ecological Properties In An Arid Area Of West Of China

As we know, ecology problem must be placed at the first in the west development. The experimental plots were located in Shahu of Ningxia autonomous region in order to investigate and analysis this area' soil physical and chemical properties, biological activity and so on. This will be benefit the soil exploitation and utilization of these kinds of regions in the future through providing some basic data and materials. The main results obtained are as follows:1. The soil physical and chemical properties are very different in this region's different plots. As far as soil texture is concerned, the content of silt particles is highest with the average of 45.03% and the content of clay particles is lowest with the average of 24.69% in every soil separates. The content of sandy particles is in middle and it was variation in all different plots and soil layers, so we can mainly dependent in the content of sandy particles to distinguish different soil texture in this region. The soil water content is very low, and the lowest value is less than 1%. The soil water increased from the top layer to the bottom layer with the great variances in different layers. The bulk density is increased from top layer to the bottom layer, meanwhile the soil porosity is decreased. The bulk density and the soil porosity are significant vary in different soil layers and are even in different plots. The soil erodibility presents a increased trend with the deepening of the layers.2. The soil's chemical properties also present theirs distinguishing features. The PH value is very high in this region for all plots' PH value are higher than 8. The top soil layer is lowest in pH value, because there are more trees or grasses' organism that can improve the soil's chemical properties. This region is short of soil organic matter for the average value is less than 1%. The content of soil organic matter is highest in the top layer and decreased from top layer to bottom layer. The soil available P is even in every plot's soil, but the available K is obviously vary in different plots. The soil salinity is very high in this region with the average of 1110.34mS/cm. The highest salinity is discovered in the top layer, and the trend is decreasing with the deepening of soil layer.3. The relationships among all soil physical and chemical properties are very perplexed. pH value, organic matter and clay particles all take great effects on available K. There are significant correlation among porosity, bulk density and available P. The properties that mostly related with soil water content are bulk density, porosity, clay particles and sandy particles. Besides, clay particles, sandyparticles and PH value all exist closer relationship with soil erodibility.4. The soil microorganism amount and soil enzyme activity present diversity in all plots. There is significant discrepancy in different plots' soil microorganism amount. The trend of soil microorganism amount in soil's different layers is the amount decreasing when the layer deepen. The soil micro-organism amount is affected by soil bulk density, porosity and soil organic matter and exist some relationship with available K. The soil water content also affect microorganism amount by a large extent. In this region, different soil enzyme present different activities and principles. The invertase is mostly active, while three kinds of phosphates are all less active than other soil enzyme. Their trend in different soil layers of different plots is identical, they all decrease when the layer deepen. The factors of affecting each kind of soil enzyme are different. Especially, the soil enzyme present the closest relationship with the soil amount of organic matter. This region' soil can be divided by two groups through their characteristics of microorganism amount and soil enzyme.