荒漠草原不同土壤类型柠条根际土壤养分与土壤颗粒分布特征研究

以宁夏盐池县3种典型土壤灰钙土、红黏土和风沙土为对象,研究柠条根际及非根际土壤的养分、颗粒组成及分布特征,并探讨土壤养分与土壤颗粒组成之间的相关性。结果表明,不同土壤类型柠条根际土壤的颗粒组成差异明显,灰钙土中粉粒含量最高为45.95%,红黏土、风沙土依次递减,风沙土中细砂含量最高为61%,红黏土、灰钙土依次递减;土壤pH值在不同土壤类型中差异不显著(P>0.05),红黏土根际中有机碳含量分别比灰钙土和风沙土高1.29、2.12g·kg^-1,灰钙土中全氮含量分别比红黏土、风沙土高0.07、0.19g·kg^-1,差异显著(P<0.05),柠条在不同土壤类型中对土壤养分的富集率不同,风沙土中有机碳、全氮的富集率分别是红黏土的6.82、1.00倍,红黏土中速效磷的富集率分别是灰钙土和风沙土的2.69、10.38倍。土壤有机碳、全氮、全磷、碱解氮与黏、粉粒含量极显著正相关(P<0.01),与细砂、中砂含量极显著负相关(P<0.01)。由此可见,不同土壤类型影响柠条根际养分的富集率,风沙土中能够富集更多的养分,红黏土对速效养分的富集作用更强,土壤中的粉粒、细砂含量与土壤养分含量的相关性最大。

Characteristics of Soil Nutrients and Particle Size Distribution in Rhizosphere of Caragana korshinskii under Different Soil Types

In this context,we aimed at studying the difference between rhizosphere and bulk soil nutrient,soil particle distribution and analyzing the difference and relationship among three different soil types,i.e.sierozem,red clay soil and aeolian sandy soil occurring in Yanchi Country of Ningxia.The results showed that no effect on the particle size composition of the rhizosphere soil of Caragana korshinskii among different soil types.The content of silt particles was 45.95%.The red clay and aeolian sandy soil decreased gradually.The content of fine sand in the sandy soil was 61%.The sierozem decreased in turn.Soil pH was no difference among different soil types (P >0.05).The content of organic carbon in the rhizosphere soil of red clay was 1.29 and 2.12 g·kg^-1 higher than those in sierozem soil and sandy soil,respectively.The content of total nitrogen in the sierozem soil was 0.07 and 0.19 g·kg^-1 higher than those in the red clay and aeolian sandy soil,respectively (P<0.05). C.korshinskii had different enrichment rates of soil nutrients in different soil types.The enrichment rates of organic carbon and total nitrogen in the aeolian sandy soil were 6.82 times and 1 time higher than that of the red clay,respectively.The enrichment rates of available phosphorus in the red clay were 2.69 and 10.38 times higher than those in the argillaceous sierozem soil and the aeolian sandy soil,respectively.The contents of soil organic carbon,total nitrogen,total phosphorus,alkali-hydrolyzed nitrogen,and clay and silt content were significantly and positively correlated (P<0.01),and negatively correlated with the content of fine sand and medium sand (P<0.01).In conclusion,different soil types affect the enrichment ratio of the nutrients in the rhizosphere soil of C.korshinskii .It is possible to accumulate more nutrients in the aeolian sandy soil,and the red clay has a stronger effect on the enrichment of available nutrients.The correlation among silt,fine sand and soil nutrient content is the greatest.