Soil Nutrient Index Characteristics of Relict Plant Gymnocarpos przewalskii Population in Desert Area of Northwest China

Gymnocarpos przewalskii was the experimental material which was a kind of relict plant that collected from 16 populations of soil in main distribution area. Main chemical indexes of different soils and the relationship between environmental factors were analyzed. The soil fertility and soil fertility of different populations were discussed. The results showed that: The variability of soil chemical indexes of different population were different among different regions, and the variation of water content was the largest, and the variation of total phosphorus was the lowest. There were significant differences in the chemical indexes in the population of G.przewalskii in different regions. There were no significant differences in the vertical distribution of soil chemical indexes. There was a significant positive correlation between soil water content and available potassium and total nitrogen and total potassium, but significant negative correlation with soil pH value. The comprehensive soil fertility in Xinjiang is generally higher than in Gansu. Soil fertility at different levels was highest in topsoil, lower in 20-40 cm range. The effects of longitude, altitude and precipitation on the main chemical index were low. The relative temperature index showed highly significant or significant negative correlation with some chemical indicators in the soil, which indicated that the temperature had an effect on the change of these indexes.