黄土高原宁南山区土壤养分空间分布特征.

[Objective] Soil nutrients and their spatial distribution are important ecological factors to ensure ecosystem health. The aim of this study is to analyze the soil nutrients and their spatial characteristics, which is of great significance for soil nutrient management and land sustainable use in this region. [Methods] In this study, different land use types were selected in the semi-arid loess hilly area, and soil nutrients were measured, and analyzed by the geostatistical method. [Results] The results showed that the total soil nutrients of different land uses in the loess hill were at the lower than medium level, and the nutrient content of different land use types in 0—20 cm soil layer was higher than that in 20—40 cm soil layer, showing surface aggregation effect. On the whole, the soil nutrient content showed the order of natural grassland ＞Caragana Korshinskii ＞ apricot ＞bare land ＞terrace ＞grassland, and the soil nutrient content of the natural grassland was significantly higher than that other vegetation types (p＜0.05）. From the spatial distribution of soil nutrients, it can be seen that soil organic carbon content is low in the middle and high in the north and south. Soil available P content was high in the middle and low in the north and south. Soil nitrate nitrogen and ammonium nitrogen contents increased gradually from south to north. [Conclusion] The artificial planting of Caragana Korshinskii and apricot was beneficial to improve the comprehensive level of soil quality in this area. Therefore, land conservation measures such as returning farmland to forest (grass) can continuously improve local soil quality. [ABSTRACT FROM AUTHOR]