扬黄灌区土壤颗粒组成与盐分离子的分布特征及其对应关系

Distribution Characteristics and Corresponding Relation Between Soil Particle Composition and Salt Ion Composition in Ningxia Pumping Irrigation Area

以扬黄灌区不同地类的土壤颗粒组成与盐分离子分布特征为分析对象,采用RDA方法研究了不同等级颗粒和不同盐分离子间的对应关系。结果表明：细砂粒、粉粒和粘粒系土壤颗粒的主要成分,研究区土壤质地以沙壤土为主。具有潜在沙化趋势的地块集中在沙化玉米地和5年玉米地表层土壤。枸杞地盐离子含量显著高于玉米地,潜在盐渍化风险较高;随种植年限的延长,各种盐离子的含量有所降低。基于冗余分析（RDA）分析,0~10cm和20~40cm土层,粘粒和粉粒均对土壤盐离子响应有显著性解释（P=0.002）,其解释量分别占所有土壤粒径参数解释量的63.64%、33.77%和69.12%、27.94%。60~80cm土层,

Based on the distribution of soil particle composition and salt ions among different land use types in Yellow River irrigation area,the RDA method analysis was used to analysis their relationships.The results showed that,soil texture in the study area was sandy loam,including fine sand,silt,and clay particles as the main.Reclamation had significantly changed vertical distribution patterns of soil texture,as the effect by cultivation methods and cropping duration.There was a risk of desertification for corn lands under transitional utilization.Overall,sandy corn salt ions content,unused salt ions content,medlar was significantly higher than that of corn.Unused land of the accumulation of salt ions were most prominent,effect of the lycium barbarum water desalination was more obvious.With the increase of planting age,contents of alkali ions showed a downward trend,and mobility the ability of chloride,sodium and sulfate ions.With varying degrees of salinization of soil environmental quality and characteristics of alkalization was not obvious.Based on soil particle composition and RAD analysis of saline-alkali Ionic composition,0-10 cm,and 20-40 cm soil,affecting soil salinity changed of ion concentration and particle size of 6parameters,D≤0.002 mm and 0.002mmD≤0.02 mm size sand content of soil salinity ions responded significantly to explain（P=0.002）,they explained all the soil grain size parameters are interpreted respectively as 63.64%,33.77%and 69.12%,27.94%.60-80 cm soil,0.02mmD≤0.05 mm grain diameter sand content on soil saline ion response had significantly explained（P=0.004）,its explained volume accounted for all soil grain diameter parameter explained volume of 81.08%,but this explained volume only for37%.Different land management and utilization years led to significant changes in the basic distribution of soil particle composition and salt ions,secondary degradation of partial classes were still potential risks.There was a significant relationship between the salt ions and soil particle composition,soil clay and silt content significantly changed the distribution of salt ions in surface and plow soil,and fine sand may be more prominent role at the bottom of soil.