陕北黄土丘陵沟壑区高速公路边坡不同生物防护模式的土壤特性—以铜（川）-黄（陵）-延（安）高速公路为例

以陕西省铜川-黄陵-延安高速公路（简称铜延高速公路）为例，选取不同防护模式（穴状整地植草模式、挂网喷播植草模式、骨架植草模式）下有代表性的18个边坡为研究对象，通过边坡土壤特性数据的处理分析，发现：1）铜延高速公路边坡干旱缺水，肥力匮乏，有机质和全氮处于极缺乏和缺乏等级，速效磷处于中等等级，平均含量为16．28mg／kg；2）土壤水分、土壤养分以及植被盖度均表现为阴坡〉阳坡，而土壤密度则是阳坡〉阴坡；土壤水分含量呈现下坡位〉上坡位〉中坡位规律，土壤养分含量呈现从上坡位到下坡位逐渐升高，有自上而下累积的趋势，植被盖度呈现明显的分层现象，表现为下坡位〉上坡位〉中坡位；3）3种护坡模式中，骨架植草模式涵养水分能力最强，其次是穴状整地植草模式，最后是挂网喷播植草模式；4）水分是黄土高原地区高速公路边坡防护成功与否的关键因子，另外施加有机肥和氮肥，保护和收集表层土，增施磷肥以及合理确定边坡坡度和斜面长对边坡的保水保肥性和稳定性意义重大。

Soil features on slopes of expressway under different biological protection models in the Hilly-gully Region of Loess Plateau: Taking Tongchuan-Huangling-Yan' an expressway as an example

This paper selected 18 slopes under the protection models of hole shape soil prepared seeding(HSSPS),net-suspended spray seeding(NSSS),framework seeding(FS) as study objects,analyzed slopes' soil features.The results indicate: 1) The slope of Tong-Yan expressway is dry,and the fertility is deficient.Organic matter and total N are at the extremely deficient and deficient rank.The average content of available P is 16.28 mg/kg,at medium rank.2) The descending order of soil water、soil nutrient content and plant coverage performances is shady slopes,sunny slopes;order of soil bulk density performances is sunny slopes,shady slopes.Order of water content is lower slopes,upper slopes and middle slopes.Soil nutrient content elevates gradually from the upper slopes to the lower slopes.Order of plant coverage is lower slopes,upper slopes and middle slopes,and presents obvious stratification.3) Comparing the three slope protection models,FS model has the strongest ability of control moisture,then is the HSSPS model,and the lowest is the NSSS model.4) Water content is the key factor of expressway slope protection in Loess Plateau.Moreover,application of organic and nitrogenous fertilizer,protecting and collecting surface soil,increasing phosphate fertilizer and selecting the slope's degree and inclining length reasonably are very important on water and nutrient conservation and stability of slope.